反射便の作り方

# MIT License
#
# Copyright (c) 2026 Pyxel 100 contributors
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
#
# The bundled Noto-derived bitmap glyphs are separately licensed under SIL OFL.
# See assets/NOTO-LICENSE.txt.
# This teaching edition contains no Noto-derived glyph data.

"""反射便・教材 1/5。単独で起動できる学習用ファイル。
実行: python 01_aim.py
詳しい数式と段階ごとの差分は LESSON.md を参照。
"""
from dataclasses import dataclass, field
import math

FPS = 30
DT = 1 / 120
SPEED = 96.0                 # px / second
RADIUS = 2.0                 # envelope collision radius
EPS = 1e-8
INITIAL_ANGLE = -45.0
SOLUTION_ANGLE = -50.75


@dataclass(frozen=True)
class Wall:
    box: tuple
    mirror: bool = False
    name: str = "wall"


@dataclass(frozen=True)
class Level:
    start: tuple
    target: tuple
    radius: float
    walls: tuple


# 原作の2便目「塀の向こう」。壁の順序も原作と同じ。
LEVEL = Level((32, 96), (160, 96), 6, (
    Wall((0, 0, 192, 16), True, "top"),
    Wall((176, 16, 192, 128), False, "right"),
    Wall((0, 116, 176, 128)),
    Wall((0, 16, 16, 116)),
    Wall((92, 64, 100, 116)),
))


@dataclass
class Flight:
    pos: tuple
    vel: tuple = (0.0, 0.0)
    status: str = "flying"
    bounces: int = 0
    age: float = 0.0
    trace: list = field(default_factory=list)
    used: str = "none"

    def __post_init__(self):
        if not self.trace:
            self.trace = [self.pos]


class World:
    def __init__(self, level=LEVEL):
        self.level = level
        self.reset()

    def reset(self):
        self.angle = INITIAL_ANGLE
        self.shot_angle = None
        self.flight = None
        self.paused = False

    def fire(self):
        if self.flight is not None:
            return False
        self.shot_angle = self.angle
        self.flight = Flight(self.level.start, status="aimed")
        return True

    def control(self, pressed=(), held=()):
        # R と Space が同時でも初期化だけ。押下と長押しを分ける。
        if "R" in pressed:
            self.reset()
            return

        if self.flight is None:
            self.angle += 2 * (("RIGHT" in held) - ("LEFT" in held))
            self.angle += 0.25 * (("DOWN" in held) - ("UP" in held))
            self.angle = (self.angle + 180) % 360 - 180
            if "SPACE" in pressed:
                self.fire()


    def checkpoint(self):
        """QA専用の自動入力・モデル進行。人のプレイ記録ではない。"""
        self.angle = SOLUTION_ANGLE
        self.fire()
        return


STAGE = 1
STAGE_TITLE = 'AIM ONCE'
NOTE = 'SPACE SAVES THE ANGLE. MOVEMENT COMES NEXT.'
MIRROR_LABEL = 'MIRROR: NOT ACTIVE YET'


class App:
    def __init__(self, engine, headless=False, screenshot=None, checkpoint=False):
        self.pyxel = engine
        self.world = World()
        self.headless = headless
        self.screenshot = screenshot
        self.draws = 0
        if checkpoint:
            self.world.checkpoint()

    def update(self):
        p = self.pyxel
        # 12回描画した画面を保存。ゲームクリア検証とは別の起動検証。
        if self.headless and self.draws >= 12:
            if self.screenshot:
                p.screenshot(self.screenshot, scale=2)
            p.quit()
            return
        pressed = {key for key in ("R", "SPACE", "P") if p.btnp(getattr(p, "KEY_" + key))}
        held = {key for key in ("LEFT", "RIGHT", "UP", "DOWN") if p.btn(getattr(p, "KEY_" + key))}
        self.world.control(pressed, held)

    def draw(self):
        p, w = self.pyxel, self.world
        f = w.flight
        p.cls(1)
        p.rect(32, 32, 320, 200, 3)
        for x in range(40, 350, 16):
            for y in range(42, 230, 16):
                p.pset(x, y, 5)
        for wall in w.level.walls:
            x, y, xx, yy = wall.box
            p.rect(x * 2, y * 2, (xx - x) * 2, (yy - y) * 2, 13 if wall.mirror else 4)
            if wall.mirror:
                p.rect(x * 2, yy * 2 - 4, (xx - x) * 2, 4, 7)
                for a in range(int(x * 2), int(xx * 2), 12):
                    p.line(a, yy * 2 - 10, a + 5, yy * 2 - 5, 6)
            else:
                for b in range(int(y * 2) + 4, int(yy * 2), 10):
                    p.line(x * 2, b, xx * 2 - 1, b, 9)
        tx, ty = (value * 2 for value in w.level.target)
        p.rect(tx - 14, ty - 14, 29, 29, 8)
        p.circ(tx, ty, w.level.radius * 2 + 2, 7)
        p.circ(tx, ty, w.level.radius * 2, 0)
        p.text(tx - 12, ty - 26, "TARGET", 7)
        p.text(42, 39, MIRROR_LABEL, 6)
        sx, sy = (value * 2 for value in w.level.start)
        angle = math.radians(w.angle if w.shot_angle is None else w.shot_angle)
        ex, ey = sx + 28 * math.cos(angle), sy + 28 * math.sin(angle)
        p.circ(sx, sy, 9, 5)
        p.line(sx, sy, ex, ey, 10)
        for sign in (-1, 1):
            p.line(ex, ey, ex - 8 * math.cos(angle + sign * 0.45), ey - 8 * math.sin(angle + sign * 0.45), 10)
        p.text(sx - 10, sy + 17, "START", 6)
        if f:
            points = f.trace + [f.pos]
            for a, b in zip(points, points[1:]):
                p.line(a[0] * 2, a[1] * 2, b[0] * 2, b[1] * 2, 6)
            for x, y in f.trace[1:]:
                p.circb(x * 2, y * 2, 4, 10)
            if f.status == "delivered":
                p.circb(tx, ty, 19, 10)
                p.line(tx - 6, ty, tx - 1, ty + 5, 10)
                p.line(tx - 1, ty + 5, tx + 8, ty - 6, 10)
            elif f.status in ("wall", "twice", "outside"):
                x, y = f.pos[0] * 2, f.pos[1] * 2
                p.line(x - 5, y - 5, x + 5, y + 5, 8)
                p.line(x - 5, y + 5, x + 5, y - 5, 8)
        px, py = (f.pos if f and f.status in ("flying", "aimed") else w.level.start)
        p.rect(px * 2 - 5, py * 2 - 3, 11, 7, 10)
        p.rectb(px * 2 - 5, py * 2 - 3, 11, 7, 7)
        p.line(px * 2 - 5, py * 2 - 3, px * 2, py * 2 + 1, 9)
        p.line(px * 2 + 5, py * 2 - 3, px * 2, py * 2 + 1, 9)
        p.rect(0, 0, 384, 20, 1)
        p.text(12, 7, f"REFLECTION MAIL / {STAGE}/5 / {STAGE_TITLE}", 7)
        p.rect(0, 256, 384, 104, 1)
        status = "AIM: ONE SHOT PER TRY" if f is None else {
            "aimed": "LOCKED: DIRECTION SAVED", "flying": "FLYING",
            "delivered": "DELIVERED!", "wall": "STOP: WALL",
            "twice": "STOP: SECOND MIRROR", "outside": "STOP: OUTSIDE / 6 SECONDS",
        }[f.status]
        if w.paused:
            status = "PAUSED"
        p.text(12, 267, status, 10)
        p.text(12, 282, f"ANGLE {w.angle:+07.2f}   TIME {f.age if f else 0:04.2f}s   BOUNCES {f.bounces if f else 0}/1", 7)
        p.text(12, 296, NOTE, 6)
        p.text(12, 314, "LEFT/RIGHT: AIM   UP/DOWN: FINE   SPACE: SEND", 7)
        p.text(12, 328, "R: RETRY   ESC: QUIT" + ("   P: PAUSE" if STAGE == 5 else ""), 6)
        p.text(12, 345, "MODEL: PIXELS / SECONDS / ONE DELIVERY", 5)
        self.draws += 1


def main(headless=False, screenshot=None, checkpoint=False):
    import pyxel

    pyxel.init(384, 360, title=f"Reflection Mail - Stage {STAGE}", fps=FPS, headless=headless)
    app = App(pyxel, headless, screenshot, checkpoint)
    pyxel.run(app.update, app.draw)


if __name__ == "__main__":
    import argparse

    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("--headless-smoke", action="store_true", help="render 12 frames and quit")
    parser.add_argument("--screenshot", help="PNG path, requires --headless-smoke")
    parser.add_argument("--demo-checkpoint", action="store_true", help="synthetic model outcome for QA, not human play")
    args = parser.parse_args()
    if args.screenshot and not args.headless_smoke:
        parser.error("--screenshot requires --headless-smoke")
    main(args.headless_smoke, args.screenshot, args.demo_checkpoint)

# MIT License
#
# Copyright (c) 2026 Pyxel 100 contributors
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
#
# The bundled Noto-derived bitmap glyphs are separately licensed under SIL OFL.
# See assets/NOTO-LICENSE.txt.
# This teaching edition contains no Noto-derived glyph data.

"""反射便・教材 2/5。単独で起動できる学習用ファイル。
実行: python 02_velocity.py
詳しい数式と段階ごとの差分は LESSON.md を参照。
"""
from dataclasses import dataclass, field
import math

FPS = 30
DT = 1 / 120
SPEED = 96.0                 # px / second
RADIUS = 2.0                 # envelope collision radius
EPS = 1e-8
INITIAL_ANGLE = -45.0
SOLUTION_ANGLE = -50.75


@dataclass(frozen=True)
class Wall:
    box: tuple
    mirror: bool = False
    name: str = "wall"


@dataclass(frozen=True)
class Level:
    start: tuple
    target: tuple
    radius: float
    walls: tuple


# 原作の2便目「塀の向こう」。壁の順序も原作と同じ。
LEVEL = Level((32, 96), (160, 96), 6, (
    Wall((0, 0, 192, 16), True, "top"),
    Wall((176, 16, 192, 128), False, "right"),
    Wall((0, 116, 176, 128)),
    Wall((0, 16, 16, 116)),
    Wall((92, 64, 100, 116)),
))


@dataclass
class Flight:
    pos: tuple
    vel: tuple = (0.0, 0.0)
    status: str = "flying"
    bounces: int = 0
    age: float = 0.0
    trace: list = field(default_factory=list)
    used: str = "none"

    def __post_init__(self):
        if not self.trace:
            self.trace = [self.pos]


def launch(level, angle):
    """angle はラジアン。画面では右が0、下向きが正。"""
    if not math.isfinite(angle):
        raise ValueError("angle must be finite")
    return Flight(level.start, (SPEED * math.cos(angle), SPEED * math.sin(angle)))


def step(level, f, dt=DT):
    if dt < 0 or not math.isfinite(dt):
        raise ValueError("invalid dt")
    if f.status != "flying":
        return f
    f.age += dt
    f.pos = (f.pos[0] + f.vel[0] * dt, f.pos[1] + f.vel[1] * dt)
    if f.status == "flying" and (not 0 <= f.pos[0] <= 192 or not 0 <= f.pos[1] <= 128):
        f.status = "outside"
    if f.status == "flying" and f.age >= 6:
        f.status = "outside"  # 原作も時間切れと場外は同じ状態
    return f


class World:
    def __init__(self, level=LEVEL):
        self.level = level
        self.reset()

    def reset(self):
        self.angle = INITIAL_ANGLE
        self.shot_angle = None
        self.flight = None
        self.paused = False

    def fire(self):
        if self.flight is not None:
            return False
        self.shot_angle = self.angle
        self.flight = launch(self.level, math.radians(self.angle))
        return True

    def control(self, pressed=(), held=()):
        # R と Space が同時でも初期化だけ。押下と長押しを分ける。
        if "R" in pressed:
            self.reset()
            return

        if self.flight is None:
            self.angle += 2 * (("RIGHT" in held) - ("LEFT" in held))
            self.angle += 0.25 * (("DOWN" in held) - ("UP" in held))
            self.angle = (self.angle + 180) % 360 - 180
            if "SPACE" in pressed:
                self.fire()
        if self.flight is not None:
            for _ in range(4):
                step(self.level, self.flight, DT)

    def checkpoint(self):
        """QA専用の自動入力・モデル進行。人のプレイ記録ではない。"""
        self.angle = SOLUTION_ANGLE
        self.fire()
        for _ in range(900):
            if self.flight.status != "flying":
                return
            self.control()
        raise AssertionError("checkpoint did not stop")


STAGE = 2
STAGE_TITLE = 'VELOCITY'
NOTE = 'WALLS ARE VISUAL ONLY IN THIS STEP.'
MIRROR_LABEL = 'MIRROR: NOT ACTIVE YET'


class App:
    def __init__(self, engine, headless=False, screenshot=None, checkpoint=False):
        self.pyxel = engine
        self.world = World()
        self.headless = headless
        self.screenshot = screenshot
        self.draws = 0
        if checkpoint:
            self.world.checkpoint()

    def update(self):
        p = self.pyxel
        # 12回描画した画面を保存。ゲームクリア検証とは別の起動検証。
        if self.headless and self.draws >= 12:
            if self.screenshot:
                p.screenshot(self.screenshot, scale=2)
            p.quit()
            return
        pressed = {key for key in ("R", "SPACE", "P") if p.btnp(getattr(p, "KEY_" + key))}
        held = {key for key in ("LEFT", "RIGHT", "UP", "DOWN") if p.btn(getattr(p, "KEY_" + key))}
        self.world.control(pressed, held)

    def draw(self):
        p, w = self.pyxel, self.world
        f = w.flight
        p.cls(1)
        p.rect(32, 32, 320, 200, 3)
        for x in range(40, 350, 16):
            for y in range(42, 230, 16):
                p.pset(x, y, 5)
        for wall in w.level.walls:
            x, y, xx, yy = wall.box
            p.rect(x * 2, y * 2, (xx - x) * 2, (yy - y) * 2, 13 if wall.mirror else 4)
            if wall.mirror:
                p.rect(x * 2, yy * 2 - 4, (xx - x) * 2, 4, 7)
                for a in range(int(x * 2), int(xx * 2), 12):
                    p.line(a, yy * 2 - 10, a + 5, yy * 2 - 5, 6)
            else:
                for b in range(int(y * 2) + 4, int(yy * 2), 10):
                    p.line(x * 2, b, xx * 2 - 1, b, 9)
        tx, ty = (value * 2 for value in w.level.target)
        p.rect(tx - 14, ty - 14, 29, 29, 8)
        p.circ(tx, ty, w.level.radius * 2 + 2, 7)
        p.circ(tx, ty, w.level.radius * 2, 0)
        p.text(tx - 12, ty - 26, "TARGET", 7)
        p.text(42, 39, MIRROR_LABEL, 6)
        sx, sy = (value * 2 for value in w.level.start)
        angle = math.radians(w.angle if w.shot_angle is None else w.shot_angle)
        ex, ey = sx + 28 * math.cos(angle), sy + 28 * math.sin(angle)
        p.circ(sx, sy, 9, 5)
        p.line(sx, sy, ex, ey, 10)
        for sign in (-1, 1):
            p.line(ex, ey, ex - 8 * math.cos(angle + sign * 0.45), ey - 8 * math.sin(angle + sign * 0.45), 10)
        p.text(sx - 10, sy + 17, "START", 6)
        if f:
            points = f.trace + [f.pos]
            for a, b in zip(points, points[1:]):
                p.line(a[0] * 2, a[1] * 2, b[0] * 2, b[1] * 2, 6)
            for x, y in f.trace[1:]:
                p.circb(x * 2, y * 2, 4, 10)
            if f.status == "delivered":
                p.circb(tx, ty, 19, 10)
                p.line(tx - 6, ty, tx - 1, ty + 5, 10)
                p.line(tx - 1, ty + 5, tx + 8, ty - 6, 10)
            elif f.status in ("wall", "twice", "outside"):
                x, y = f.pos[0] * 2, f.pos[1] * 2
                p.line(x - 5, y - 5, x + 5, y + 5, 8)
                p.line(x - 5, y + 5, x + 5, y - 5, 8)
        px, py = (f.pos if f and f.status in ("flying", "aimed") else w.level.start)
        p.rect(px * 2 - 5, py * 2 - 3, 11, 7, 10)
        p.rectb(px * 2 - 5, py * 2 - 3, 11, 7, 7)
        p.line(px * 2 - 5, py * 2 - 3, px * 2, py * 2 + 1, 9)
        p.line(px * 2 + 5, py * 2 - 3, px * 2, py * 2 + 1, 9)
        p.rect(0, 0, 384, 20, 1)
        p.text(12, 7, f"REFLECTION MAIL / {STAGE}/5 / {STAGE_TITLE}", 7)
        p.rect(0, 256, 384, 104, 1)
        status = "AIM: ONE SHOT PER TRY" if f is None else {
            "aimed": "LOCKED: DIRECTION SAVED", "flying": "FLYING",
            "delivered": "DELIVERED!", "wall": "STOP: WALL",
            "twice": "STOP: SECOND MIRROR", "outside": "STOP: OUTSIDE / 6 SECONDS",
        }[f.status]
        if w.paused:
            status = "PAUSED"
        p.text(12, 267, status, 10)
        p.text(12, 282, f"ANGLE {w.angle:+07.2f}   TIME {f.age if f else 0:04.2f}s   BOUNCES {f.bounces if f else 0}/1", 7)
        p.text(12, 296, NOTE, 6)
        p.text(12, 314, "LEFT/RIGHT: AIM   UP/DOWN: FINE   SPACE: SEND", 7)
        p.text(12, 328, "R: RETRY   ESC: QUIT" + ("   P: PAUSE" if STAGE == 5 else ""), 6)
        p.text(12, 345, "MODEL: PIXELS / SECONDS / ONE DELIVERY", 5)
        self.draws += 1


def main(headless=False, screenshot=None, checkpoint=False):
    import pyxel

    pyxel.init(384, 360, title=f"Reflection Mail - Stage {STAGE}", fps=FPS, headless=headless)
    app = App(pyxel, headless, screenshot, checkpoint)
    pyxel.run(app.update, app.draw)


if __name__ == "__main__":
    import argparse

    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("--headless-smoke", action="store_true", help="render 12 frames and quit")
    parser.add_argument("--screenshot", help="PNG path, requires --headless-smoke")
    parser.add_argument("--demo-checkpoint", action="store_true", help="synthetic model outcome for QA, not human play")
    args = parser.parse_args()
    if args.screenshot and not args.headless_smoke:
        parser.error("--screenshot requires --headless-smoke")
    main(args.headless_smoke, args.screenshot, args.demo_checkpoint)

# MIT License
#
# Copyright (c) 2026 Pyxel 100 contributors
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
#
# The bundled Noto-derived bitmap glyphs are separately licensed under SIL OFL.
# See assets/NOTO-LICENSE.txt.
# This teaching edition contains no Noto-derived glyph data.

"""反射便・教材 3/5。単独で起動できる学習用ファイル。
実行: python 03_sweep.py
詳しい数式と段階ごとの差分は LESSON.md を参照。
"""
from dataclasses import dataclass, field
import math

FPS = 30
DT = 1 / 120
SPEED = 96.0                 # px / second
RADIUS = 2.0                 # envelope collision radius
EPS = 1e-8
INITIAL_ANGLE = -45.0
SOLUTION_ANGLE = -50.75


@dataclass(frozen=True)
class Wall:
    box: tuple
    mirror: bool = False
    name: str = "wall"


@dataclass(frozen=True)
class Level:
    start: tuple
    target: tuple
    radius: float
    walls: tuple


# 原作の2便目「塀の向こう」。壁の順序も原作と同じ。
LEVEL = Level((32, 96), (160, 96), 6, (
    Wall((0, 0, 192, 16), True, "top"),
    Wall((176, 16, 192, 128), False, "right"),
    Wall((0, 116, 176, 128)),
    Wall((0, 16, 16, 116)),
    Wall((92, 64, 100, 116)),
))


@dataclass
class Flight:
    pos: tuple
    vel: tuple = (0.0, 0.0)
    status: str = "flying"
    bounces: int = 0
    age: float = 0.0
    trace: list = field(default_factory=list)
    used: str = "none"

    def __post_init__(self):
        if not self.trace:
            self.trace = [self.pos]


def launch(level, angle):
    """angle はラジアン。画面では右が0、下向きが正。"""
    if not math.isfinite(angle):
        raise ValueError("angle must be finite")
    return Flight(level.start, (SPEED * math.cos(angle), SPEED * math.sin(angle)))


def ray_box(p, d, box, r=RADIUS):
    """p から p+d への掃引。最初の t と単位法線を返す。"""
    near, far = -math.inf, math.inf
    normal = (0, 0)
    for axis in (0, 1):       # 同時の角接触は X 軸を優先
        lo, hi = box[axis] - r, box[axis + 2] + r
        if abs(d[axis]) < EPS:
            if p[axis] < lo or p[axis] > hi:
                return None
            continue
        a, b = (lo - p[axis]) / d[axis], (hi - p[axis]) / d[axis]
        n = [0, 0]
        n[axis] = -1 if d[axis] > 0 else 1
        if a > b:
            a, b = b, a
        if a > near:
            near, normal = a, tuple(n)
        far = min(far, b)
        if near > far + EPS:
            return None
    if far < 0 or near > 1 or near < -EPS:
        return None
    return max(0, near), normal


def ray_circle(p, d, c, r):
    """中心 p+t*d と受取口の距離が r になる最初の t。"""
    a = d[0] ** 2 + d[1] ** 2
    q = (p[0] - c[0], p[1] - c[1])
    cc = q[0] ** 2 + q[1] ** 2 - r * r
    if cc <= 0:
        return 0.0
    if a < EPS:
        return None
    b = 2 * (q[0] * d[0] + q[1] * d[1])
    discriminant = b * b - 4 * a * cc
    if discriminant < 0:
        return None
    t = (-b - math.sqrt(max(0, discriminant))) / (2 * a)
    return t if 0 <= t <= 1 else None


def first_contact(level, p, d):
    hits = []
    for index, wall in enumerate(level.walls):
        hit = ray_box(p, d, wall.box)
        if hit is not None:
            hits.append((hit[0], index, hit[1], wall))
    # 原作の決定規則: 小数9桁に丸めた時刻、次に壁の番号。
    wall_hit = min(hits, key=lambda hit: (round(hit[0], 9), hit[1])) if hits else None
    target_t = ray_circle(p, d, level.target, level.radius)
    # 同時または EPS 以内なら壁を優先する。
    if target_t is not None and (wall_hit is None or target_t < wall_hit[0] - EPS):
        return (target_t, "target", (0, 0), None)
    if wall_hit is not None:
        t, _, normal, wall = wall_hit
        return (t, "wall", normal, wall)
    return None


def step(level, f, dt=DT):
    if dt < 0 or not math.isfinite(dt):
        raise ValueError("invalid dt")
    if f.status != "flying":
        return f
    f.age += dt
    d = (f.vel[0] * dt, f.vel[1] * dt)
    hit = first_contact(level, f.pos, d)
    if hit is None:
        f.pos = (f.pos[0] + d[0], f.pos[1] + d[1])
    else:
        t, kind, normal, wall = hit
        f.pos = (f.pos[0] + d[0] * t, f.pos[1] + d[1] * t)
        f.trace.append(f.pos)
        f.status = "delivered" if kind == "target" else "wall"
    if f.status == "flying" and (not 0 <= f.pos[0] <= 192 or not 0 <= f.pos[1] <= 128):
        f.status = "outside"
    if f.status == "flying" and f.age >= 6:
        f.status = "outside"  # 原作も時間切れと場外は同じ状態
    return f


class World:
    def __init__(self, level=LEVEL):
        self.level = level
        self.reset()

    def reset(self):
        self.angle = INITIAL_ANGLE
        self.shot_angle = None
        self.flight = None
        self.paused = False

    def fire(self):
        if self.flight is not None:
            return False
        self.shot_angle = self.angle
        self.flight = launch(self.level, math.radians(self.angle))
        return True

    def control(self, pressed=(), held=()):
        # R と Space が同時でも初期化だけ。押下と長押しを分ける。
        if "R" in pressed:
            self.reset()
            return

        if self.flight is None:
            self.angle += 2 * (("RIGHT" in held) - ("LEFT" in held))
            self.angle += 0.25 * (("DOWN" in held) - ("UP" in held))
            self.angle = (self.angle + 180) % 360 - 180
            if "SPACE" in pressed:
                self.fire()
        if self.flight is not None:
            for _ in range(4):
                step(self.level, self.flight, DT)

    def checkpoint(self):
        """QA専用の自動入力・モデル進行。人のプレイ記録ではない。"""
        self.angle = SOLUTION_ANGLE
        self.fire()
        for _ in range(900):
            if self.flight.status != "flying":
                return
            self.control()
        raise AssertionError("checkpoint did not stop")


STAGE = 3
STAGE_TITLE = 'FIRST CONTACT'
NOTE = 'ALL WALLS STOP THE LETTER IN THIS STEP.'
MIRROR_LABEL = 'MIRROR: NOT ACTIVE YET'


class App:
    def __init__(self, engine, headless=False, screenshot=None, checkpoint=False):
        self.pyxel = engine
        self.world = World()
        self.headless = headless
        self.screenshot = screenshot
        self.draws = 0
        if checkpoint:
            self.world.checkpoint()

    def update(self):
        p = self.pyxel
        # 12回描画した画面を保存。ゲームクリア検証とは別の起動検証。
        if self.headless and self.draws >= 12:
            if self.screenshot:
                p.screenshot(self.screenshot, scale=2)
            p.quit()
            return
        pressed = {key for key in ("R", "SPACE", "P") if p.btnp(getattr(p, "KEY_" + key))}
        held = {key for key in ("LEFT", "RIGHT", "UP", "DOWN") if p.btn(getattr(p, "KEY_" + key))}
        self.world.control(pressed, held)

    def draw(self):
        p, w = self.pyxel, self.world
        f = w.flight
        p.cls(1)
        p.rect(32, 32, 320, 200, 3)
        for x in range(40, 350, 16):
            for y in range(42, 230, 16):
                p.pset(x, y, 5)
        for wall in w.level.walls:
            x, y, xx, yy = wall.box
            p.rect(x * 2, y * 2, (xx - x) * 2, (yy - y) * 2, 13 if wall.mirror else 4)
            if wall.mirror:
                p.rect(x * 2, yy * 2 - 4, (xx - x) * 2, 4, 7)
                for a in range(int(x * 2), int(xx * 2), 12):
                    p.line(a, yy * 2 - 10, a + 5, yy * 2 - 5, 6)
            else:
                for b in range(int(y * 2) + 4, int(yy * 2), 10):
                    p.line(x * 2, b, xx * 2 - 1, b, 9)
        tx, ty = (value * 2 for value in w.level.target)
        p.rect(tx - 14, ty - 14, 29, 29, 8)
        p.circ(tx, ty, w.level.radius * 2 + 2, 7)
        p.circ(tx, ty, w.level.radius * 2, 0)
        p.text(tx - 12, ty - 26, "TARGET", 7)
        p.text(42, 39, MIRROR_LABEL, 6)
        sx, sy = (value * 2 for value in w.level.start)
        angle = math.radians(w.angle if w.shot_angle is None else w.shot_angle)
        ex, ey = sx + 28 * math.cos(angle), sy + 28 * math.sin(angle)
        p.circ(sx, sy, 9, 5)
        p.line(sx, sy, ex, ey, 10)
        for sign in (-1, 1):
            p.line(ex, ey, ex - 8 * math.cos(angle + sign * 0.45), ey - 8 * math.sin(angle + sign * 0.45), 10)
        p.text(sx - 10, sy + 17, "START", 6)
        if f:
            points = f.trace + [f.pos]
            for a, b in zip(points, points[1:]):
                p.line(a[0] * 2, a[1] * 2, b[0] * 2, b[1] * 2, 6)
            for x, y in f.trace[1:]:
                p.circb(x * 2, y * 2, 4, 10)
            if f.status == "delivered":
                p.circb(tx, ty, 19, 10)
                p.line(tx - 6, ty, tx - 1, ty + 5, 10)
                p.line(tx - 1, ty + 5, tx + 8, ty - 6, 10)
            elif f.status in ("wall", "twice", "outside"):
                x, y = f.pos[0] * 2, f.pos[1] * 2
                p.line(x - 5, y - 5, x + 5, y + 5, 8)
                p.line(x - 5, y + 5, x + 5, y - 5, 8)
        px, py = (f.pos if f and f.status in ("flying", "aimed") else w.level.start)
        p.rect(px * 2 - 5, py * 2 - 3, 11, 7, 10)
        p.rectb(px * 2 - 5, py * 2 - 3, 11, 7, 7)
        p.line(px * 2 - 5, py * 2 - 3, px * 2, py * 2 + 1, 9)
        p.line(px * 2 + 5, py * 2 - 3, px * 2, py * 2 + 1, 9)
        p.rect(0, 0, 384, 20, 1)
        p.text(12, 7, f"REFLECTION MAIL / {STAGE}/5 / {STAGE_TITLE}", 7)
        p.rect(0, 256, 384, 104, 1)
        status = "AIM: ONE SHOT PER TRY" if f is None else {
            "aimed": "LOCKED: DIRECTION SAVED", "flying": "FLYING",
            "delivered": "DELIVERED!", "wall": "STOP: WALL",
            "twice": "STOP: SECOND MIRROR", "outside": "STOP: OUTSIDE / 6 SECONDS",
        }[f.status]
        if w.paused:
            status = "PAUSED"
        p.text(12, 267, status, 10)
        p.text(12, 282, f"ANGLE {w.angle:+07.2f}   TIME {f.age if f else 0:04.2f}s   BOUNCES {f.bounces if f else 0}/1", 7)
        p.text(12, 296, NOTE, 6)
        p.text(12, 314, "LEFT/RIGHT: AIM   UP/DOWN: FINE   SPACE: SEND", 7)
        p.text(12, 328, "R: RETRY   ESC: QUIT" + ("   P: PAUSE" if STAGE == 5 else ""), 6)
        p.text(12, 345, "MODEL: PIXELS / SECONDS / ONE DELIVERY", 5)
        self.draws += 1


def main(headless=False, screenshot=None, checkpoint=False):
    import pyxel

    pyxel.init(384, 360, title=f"Reflection Mail - Stage {STAGE}", fps=FPS, headless=headless)
    app = App(pyxel, headless, screenshot, checkpoint)
    pyxel.run(app.update, app.draw)


if __name__ == "__main__":
    import argparse

    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("--headless-smoke", action="store_true", help="render 12 frames and quit")
    parser.add_argument("--screenshot", help="PNG path, requires --headless-smoke")
    parser.add_argument("--demo-checkpoint", action="store_true", help="synthetic model outcome for QA, not human play")
    args = parser.parse_args()
    if args.screenshot and not args.headless_smoke:
        parser.error("--screenshot requires --headless-smoke")
    main(args.headless_smoke, args.screenshot, args.demo_checkpoint)

# MIT License
#
# Copyright (c) 2026 Pyxel 100 contributors
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
#
# The bundled Noto-derived bitmap glyphs are separately licensed under SIL OFL.
# See assets/NOTO-LICENSE.txt.
# This teaching edition contains no Noto-derived glyph data.

"""反射便・教材 4/5。単独で起動できる学習用ファイル。
実行: python 04_reflect.py
詳しい数式と段階ごとの差分は LESSON.md を参照。
"""
from dataclasses import dataclass, field
import math

FPS = 30
DT = 1 / 120
SPEED = 96.0                 # px / second
RADIUS = 2.0                 # envelope collision radius
EPS = 1e-8
INITIAL_ANGLE = -45.0
SOLUTION_ANGLE = -50.75


@dataclass(frozen=True)
class Wall:
    box: tuple
    mirror: bool = False
    name: str = "wall"


@dataclass(frozen=True)
class Level:
    start: tuple
    target: tuple
    radius: float
    walls: tuple


# 原作の2便目「塀の向こう」。壁の順序も原作と同じ。
LEVEL = Level((32, 96), (160, 96), 6, (
    Wall((0, 0, 192, 16), True, "top"),
    Wall((176, 16, 192, 128), False, "right"),
    Wall((0, 116, 176, 128)),
    Wall((0, 16, 16, 116)),
    Wall((92, 64, 100, 116)),
))


@dataclass
class Flight:
    pos: tuple
    vel: tuple = (0.0, 0.0)
    status: str = "flying"
    bounces: int = 0
    age: float = 0.0
    trace: list = field(default_factory=list)
    used: str = "none"

    def __post_init__(self):
        if not self.trace:
            self.trace = [self.pos]


def launch(level, angle):
    """angle はラジアン。画面では右が0、下向きが正。"""
    if not math.isfinite(angle):
        raise ValueError("angle must be finite")
    return Flight(level.start, (SPEED * math.cos(angle), SPEED * math.sin(angle)))


def ray_box(p, d, box, r=RADIUS):
    """p から p+d への掃引。最初の t と単位法線を返す。"""
    near, far = -math.inf, math.inf
    normal = (0, 0)
    for axis in (0, 1):       # 同時の角接触は X 軸を優先
        lo, hi = box[axis] - r, box[axis + 2] + r
        if abs(d[axis]) < EPS:
            if p[axis] < lo or p[axis] > hi:
                return None
            continue
        a, b = (lo - p[axis]) / d[axis], (hi - p[axis]) / d[axis]
        n = [0, 0]
        n[axis] = -1 if d[axis] > 0 else 1
        if a > b:
            a, b = b, a
        if a > near:
            near, normal = a, tuple(n)
        far = min(far, b)
        if near > far + EPS:
            return None
    if far < 0 or near > 1 or near < -EPS:
        return None
    return max(0, near), normal


def ray_circle(p, d, c, r):
    """中心 p+t*d と受取口の距離が r になる最初の t。"""
    a = d[0] ** 2 + d[1] ** 2
    q = (p[0] - c[0], p[1] - c[1])
    cc = q[0] ** 2 + q[1] ** 2 - r * r
    if cc <= 0:
        return 0.0
    if a < EPS:
        return None
    b = 2 * (q[0] * d[0] + q[1] * d[1])
    discriminant = b * b - 4 * a * cc
    if discriminant < 0:
        return None
    t = (-b - math.sqrt(max(0, discriminant))) / (2 * a)
    return t if 0 <= t <= 1 else None


def first_contact(level, p, d):
    hits = []
    for index, wall in enumerate(level.walls):
        hit = ray_box(p, d, wall.box)
        if hit is not None:
            hits.append((hit[0], index, hit[1], wall))
    # 原作の決定規則: 小数9桁に丸めた時刻、次に壁の番号。
    wall_hit = min(hits, key=lambda hit: (round(hit[0], 9), hit[1])) if hits else None
    target_t = ray_circle(p, d, level.target, level.radius)
    # 同時または EPS 以内なら壁を優先する。
    if target_t is not None and (wall_hit is None or target_t < wall_hit[0] - EPS):
        return (target_t, "target", (0, 0), None)
    if wall_hit is not None:
        t, _, normal, wall = wall_hit
        return (t, "wall", normal, wall)
    return None


def reflect(v, n):
    """n は長さ1の法線。接線方向は残し、法線方向だけ逆にする。"""
    dot = v[0] * n[0] + v[1] * n[1]
    return (v[0] - 2 * dot * n[0], v[1] - 2 * dot * n[1])


def step(level, f, dt=DT):
    if dt < 0 or not math.isfinite(dt):
        raise ValueError("invalid dt")
    if f.status != "flying":
        return f
    f.age += dt
    d = (f.vel[0] * dt, f.vel[1] * dt)
    hit = first_contact(level, f.pos, d)
    if hit is None:
        f.pos = (f.pos[0] + d[0], f.pos[1] + d[1])
    else:
        t, kind, normal, wall = hit
        f.pos = (f.pos[0] + d[0] * t, f.pos[1] + d[1] * t)
        f.trace.append(f.pos)
        if kind == "target":
            f.status = "delivered"
        elif not wall.mirror:
            f.status = "wall"
        elif f.bounces >= 1:
            f.status = "twice"
        else:
            f.bounces += 1
            f.used = wall.name
            f.vel = reflect(f.vel, normal)
            f.pos = (f.pos[0] + normal[0] * 0.01, f.pos[1] + normal[1] * 0.01)
            # この段階の意図的な簡略化: 接触後の余り時間は捨てる。
            # 第5段階で直す。DT のとき最大0.8pxぶん遅れる。
    if f.status == "flying" and (not 0 <= f.pos[0] <= 192 or not 0 <= f.pos[1] <= 128):
        f.status = "outside"
    if f.status == "flying" and f.age >= 6:
        f.status = "outside"  # 原作も時間切れと場外は同じ状態
    return f


class World:
    def __init__(self, level=LEVEL):
        self.level = level
        self.reset()

    def reset(self):
        self.angle = INITIAL_ANGLE
        self.shot_angle = None
        self.flight = None
        self.paused = False

    def fire(self):
        if self.flight is not None:
            return False
        self.shot_angle = self.angle
        self.flight = launch(self.level, math.radians(self.angle))
        return True

    def control(self, pressed=(), held=()):
        # R と Space が同時でも初期化だけ。押下と長押しを分ける。
        if "R" in pressed:
            self.reset()
            return

        if self.flight is None:
            self.angle += 2 * (("RIGHT" in held) - ("LEFT" in held))
            self.angle += 0.25 * (("DOWN" in held) - ("UP" in held))
            self.angle = (self.angle + 180) % 360 - 180
            if "SPACE" in pressed:
                self.fire()
        if self.flight is not None:
            for _ in range(4):
                step(self.level, self.flight, DT)

    def checkpoint(self):
        """QA専用の自動入力・モデル進行。人のプレイ記録ではない。"""
        self.angle = SOLUTION_ANGLE
        self.fire()
        for _ in range(900):
            if self.flight.status != "flying":
                return
            self.control()
        raise AssertionError("checkpoint did not stop")


STAGE = 4
STAGE_TITLE = 'REFLECTION'
NOTE = 'BOUNCE RESTS UNTIL NEXT TICK IN THIS STEP.'
MIRROR_LABEL = 'WHITE MIRROR'


class App:
    def __init__(self, engine, headless=False, screenshot=None, checkpoint=False):
        self.pyxel = engine
        self.world = World()
        self.headless = headless
        self.screenshot = screenshot
        self.draws = 0
        if checkpoint:
            self.world.checkpoint()

    def update(self):
        p = self.pyxel
        # 12回描画した画面を保存。ゲームクリア検証とは別の起動検証。
        if self.headless and self.draws >= 12:
            if self.screenshot:
                p.screenshot(self.screenshot, scale=2)
            p.quit()
            return
        pressed = {key for key in ("R", "SPACE", "P") if p.btnp(getattr(p, "KEY_" + key))}
        held = {key for key in ("LEFT", "RIGHT", "UP", "DOWN") if p.btn(getattr(p, "KEY_" + key))}
        self.world.control(pressed, held)

    def draw(self):
        p, w = self.pyxel, self.world
        f = w.flight
        p.cls(1)
        p.rect(32, 32, 320, 200, 3)
        for x in range(40, 350, 16):
            for y in range(42, 230, 16):
                p.pset(x, y, 5)
        for wall in w.level.walls:
            x, y, xx, yy = wall.box
            p.rect(x * 2, y * 2, (xx - x) * 2, (yy - y) * 2, 13 if wall.mirror else 4)
            if wall.mirror:
                p.rect(x * 2, yy * 2 - 4, (xx - x) * 2, 4, 7)
                for a in range(int(x * 2), int(xx * 2), 12):
                    p.line(a, yy * 2 - 10, a + 5, yy * 2 - 5, 6)
            else:
                for b in range(int(y * 2) + 4, int(yy * 2), 10):
                    p.line(x * 2, b, xx * 2 - 1, b, 9)
        tx, ty = (value * 2 for value in w.level.target)
        p.rect(tx - 14, ty - 14, 29, 29, 8)
        p.circ(tx, ty, w.level.radius * 2 + 2, 7)
        p.circ(tx, ty, w.level.radius * 2, 0)
        p.text(tx - 12, ty - 26, "TARGET", 7)
        p.text(42, 39, MIRROR_LABEL, 6)
        sx, sy = (value * 2 for value in w.level.start)
        angle = math.radians(w.angle if w.shot_angle is None else w.shot_angle)
        ex, ey = sx + 28 * math.cos(angle), sy + 28 * math.sin(angle)
        p.circ(sx, sy, 9, 5)
        p.line(sx, sy, ex, ey, 10)
        for sign in (-1, 1):
            p.line(ex, ey, ex - 8 * math.cos(angle + sign * 0.45), ey - 8 * math.sin(angle + sign * 0.45), 10)
        p.text(sx - 10, sy + 17, "START", 6)
        if f:
            points = f.trace + [f.pos]
            for a, b in zip(points, points[1:]):
                p.line(a[0] * 2, a[1] * 2, b[0] * 2, b[1] * 2, 6)
            for x, y in f.trace[1:]:
                p.circb(x * 2, y * 2, 4, 10)
            if f.status == "delivered":
                p.circb(tx, ty, 19, 10)
                p.line(tx - 6, ty, tx - 1, ty + 5, 10)
                p.line(tx - 1, ty + 5, tx + 8, ty - 6, 10)
            elif f.status in ("wall", "twice", "outside"):
                x, y = f.pos[0] * 2, f.pos[1] * 2
                p.line(x - 5, y - 5, x + 5, y + 5, 8)
                p.line(x - 5, y + 5, x + 5, y - 5, 8)
        px, py = (f.pos if f and f.status in ("flying", "aimed") else w.level.start)
        p.rect(px * 2 - 5, py * 2 - 3, 11, 7, 10)
        p.rectb(px * 2 - 5, py * 2 - 3, 11, 7, 7)
        p.line(px * 2 - 5, py * 2 - 3, px * 2, py * 2 + 1, 9)
        p.line(px * 2 + 5, py * 2 - 3, px * 2, py * 2 + 1, 9)
        p.rect(0, 0, 384, 20, 1)
        p.text(12, 7, f"REFLECTION MAIL / {STAGE}/5 / {STAGE_TITLE}", 7)
        p.rect(0, 256, 384, 104, 1)
        status = "AIM: ONE SHOT PER TRY" if f is None else {
            "aimed": "LOCKED: DIRECTION SAVED", "flying": "FLYING",
            "delivered": "DELIVERED!", "wall": "STOP: WALL",
            "twice": "STOP: SECOND MIRROR", "outside": "STOP: OUTSIDE / 6 SECONDS",
        }[f.status]
        if w.paused:
            status = "PAUSED"
        p.text(12, 267, status, 10)
        p.text(12, 282, f"ANGLE {w.angle:+07.2f}   TIME {f.age if f else 0:04.2f}s   BOUNCES {f.bounces if f else 0}/1", 7)
        p.text(12, 296, NOTE, 6)
        p.text(12, 314, "LEFT/RIGHT: AIM   UP/DOWN: FINE   SPACE: SEND", 7)
        p.text(12, 328, "R: RETRY   ESC: QUIT" + ("   P: PAUSE" if STAGE == 5 else ""), 6)
        p.text(12, 345, "MODEL: PIXELS / SECONDS / ONE DELIVERY", 5)
        self.draws += 1


def main(headless=False, screenshot=None, checkpoint=False):
    import pyxel

    pyxel.init(384, 360, title=f"Reflection Mail - Stage {STAGE}", fps=FPS, headless=headless)
    app = App(pyxel, headless, screenshot, checkpoint)
    pyxel.run(app.update, app.draw)


if __name__ == "__main__":
    import argparse

    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("--headless-smoke", action="store_true", help="render 12 frames and quit")
    parser.add_argument("--screenshot", help="PNG path, requires --headless-smoke")
    parser.add_argument("--demo-checkpoint", action="store_true", help="synthetic model outcome for QA, not human play")
    args = parser.parse_args()
    if args.screenshot and not args.headless_smoke:
        parser.error("--screenshot requires --headless-smoke")
    main(args.headless_smoke, args.screenshot, args.demo_checkpoint)

# MIT License
#
# Copyright (c) 2026 Pyxel 100 contributors
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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# SOFTWARE.
#
# The bundled Noto-derived bitmap glyphs are separately licensed under SIL OFL.
# See assets/NOTO-LICENSE.txt.
# This teaching edition contains no Noto-derived glyph data.

"""反射便・教材 5/5。単独で起動できる学習用ファイル。
実行: python 05_remaining.py
詳しい数式と段階ごとの差分は LESSON.md を参照。
"""
from dataclasses import dataclass, field
import math

FPS = 30
DT = 1 / 120
SPEED = 96.0                 # px / second
RADIUS = 2.0                 # envelope collision radius
EPS = 1e-8
INITIAL_ANGLE = -45.0
SOLUTION_ANGLE = -50.75


@dataclass(frozen=True)
class Wall:
    box: tuple
    mirror: bool = False
    name: str = "wall"


@dataclass(frozen=True)
class Level:
    start: tuple
    target: tuple
    radius: float
    walls: tuple


# 原作の2便目「塀の向こう」。壁の順序も原作と同じ。
LEVEL = Level((32, 96), (160, 96), 6, (
    Wall((0, 0, 192, 16), True, "top"),
    Wall((176, 16, 192, 128), False, "right"),
    Wall((0, 116, 176, 128)),
    Wall((0, 16, 16, 116)),
    Wall((92, 64, 100, 116)),
))


@dataclass
class Flight:
    pos: tuple
    vel: tuple = (0.0, 0.0)
    status: str = "flying"
    bounces: int = 0
    age: float = 0.0
    trace: list = field(default_factory=list)
    used: str = "none"

    def __post_init__(self):
        if not self.trace:
            self.trace = [self.pos]


def launch(level, angle):
    """angle はラジアン。画面では右が0、下向きが正。"""
    if not math.isfinite(angle):
        raise ValueError("angle must be finite")
    return Flight(level.start, (SPEED * math.cos(angle), SPEED * math.sin(angle)))


def ray_box(p, d, box, r=RADIUS):
    """p から p+d への掃引。最初の t と単位法線を返す。"""
    near, far = -math.inf, math.inf
    normal = (0, 0)
    for axis in (0, 1):       # 同時の角接触は X 軸を優先
        lo, hi = box[axis] - r, box[axis + 2] + r
        if abs(d[axis]) < EPS:
            if p[axis] < lo or p[axis] > hi:
                return None
            continue
        a, b = (lo - p[axis]) / d[axis], (hi - p[axis]) / d[axis]
        n = [0, 0]
        n[axis] = -1 if d[axis] > 0 else 1
        if a > b:
            a, b = b, a
        if a > near:
            near, normal = a, tuple(n)
        far = min(far, b)
        if near > far + EPS:
            return None
    if far < 0 or near > 1 or near < -EPS:
        return None
    return max(0, near), normal


def ray_circle(p, d, c, r):
    """中心 p+t*d と受取口の距離が r になる最初の t。"""
    a = d[0] ** 2 + d[1] ** 2
    q = (p[0] - c[0], p[1] - c[1])
    cc = q[0] ** 2 + q[1] ** 2 - r * r
    if cc <= 0:
        return 0.0
    if a < EPS:
        return None
    b = 2 * (q[0] * d[0] + q[1] * d[1])
    discriminant = b * b - 4 * a * cc
    if discriminant < 0:
        return None
    t = (-b - math.sqrt(max(0, discriminant))) / (2 * a)
    return t if 0 <= t <= 1 else None


def first_contact(level, p, d):
    hits = []
    for index, wall in enumerate(level.walls):
        hit = ray_box(p, d, wall.box)
        if hit is not None:
            hits.append((hit[0], index, hit[1], wall))
    # 原作の決定規則: 小数9桁に丸めた時刻、次に壁の番号。
    wall_hit = min(hits, key=lambda hit: (round(hit[0], 9), hit[1])) if hits else None
    target_t = ray_circle(p, d, level.target, level.radius)
    # 同時または EPS 以内なら壁を優先する。
    if target_t is not None and (wall_hit is None or target_t < wall_hit[0] - EPS):
        return (target_t, "target", (0, 0), None)
    if wall_hit is not None:
        t, _, normal, wall = wall_hit
        return (t, "wall", normal, wall)
    return None


def reflect(v, n):
    """n は長さ1の法線。接線方向は残し、法線方向だけ逆にする。"""
    dot = v[0] * n[0] + v[1] * n[1]
    return (v[0] - 2 * dot * n[0], v[1] - 2 * dot * n[1])


def step(level, f, dt=DT):
    if dt < 0 or not math.isfinite(dt):
        raise ValueError("invalid dt")
    if f.status != "flying":
        return f
    f.age += dt
    remaining = dt
    for _ in range(4):       # 1刻みでの接触解決も有限にする
        d = (f.vel[0] * remaining, f.vel[1] * remaining)
        hit = first_contact(level, f.pos, d)
        if hit is None:
            f.pos = (f.pos[0] + d[0], f.pos[1] + d[1])
            break
        t, kind, normal, wall = hit
        f.pos = (f.pos[0] + d[0] * t, f.pos[1] + d[1] * t)
        f.trace.append(f.pos)
        if kind == "target":
            f.status = "delivered"
            break
        if not wall.mirror:
            f.status = "wall"
            break
        if f.bounces >= 1:
            f.status = "twice"
            break
        f.bounces += 1
        f.used = wall.name
        f.vel = reflect(f.vel, normal)
        f.pos = (f.pos[0] + normal[0] * 0.01, f.pos[1] + normal[1] * 0.01)
        remaining *= 1 - t
        if remaining < EPS:
            break
    if f.status == "flying" and (not 0 <= f.pos[0] <= 192 or not 0 <= f.pos[1] <= 128):
        f.status = "outside"
    if f.status == "flying" and f.age >= 6:
        f.status = "outside"  # 原作も時間切れと場外は同じ状態
    return f


class World:
    def __init__(self, level=LEVEL):
        self.level = level
        self.reset()

    def reset(self):
        self.angle = INITIAL_ANGLE
        self.shot_angle = None
        self.flight = None
        self.paused = False

    def fire(self):
        if self.flight is not None:
            return False
        self.shot_angle = self.angle
        self.flight = launch(self.level, math.radians(self.angle))
        return True

    def control(self, pressed=(), held=()):
        # R と Space が同時でも初期化だけ。押下と長押しを分ける。
        if "R" in pressed:
            self.reset()
            return
        if "P" in pressed:
            self.paused = not self.paused
            return
        if self.paused:
            return
        if self.flight is None:
            self.angle += 2 * (("RIGHT" in held) - ("LEFT" in held))
            self.angle += 0.25 * (("DOWN" in held) - ("UP" in held))
            self.angle = (self.angle + 180) % 360 - 180
            if "SPACE" in pressed:
                self.fire()
        if self.flight is not None:
            for _ in range(4):
                step(self.level, self.flight, DT)

    def checkpoint(self):
        """QA専用の自動入力・モデル進行。人のプレイ記録ではない。"""
        self.angle = SOLUTION_ANGLE
        self.fire()
        for _ in range(900):
            if self.flight.status != "flying":
                return
            self.control()
        raise AssertionError("checkpoint did not stop")


STAGE = 5
STAGE_TITLE = 'REMAINING TIME'
NOTE = 'SWEEP -> FIRST HIT -> REFLECT -> USE TIME.'
MIRROR_LABEL = 'WHITE MIRROR'


class App:
    def __init__(self, engine, headless=False, screenshot=None, checkpoint=False):
        self.pyxel = engine
        self.world = World()
        self.headless = headless
        self.screenshot = screenshot
        self.draws = 0
        if checkpoint:
            self.world.checkpoint()

    def update(self):
        p = self.pyxel
        # 12回描画した画面を保存。ゲームクリア検証とは別の起動検証。
        if self.headless and self.draws >= 12:
            if self.screenshot:
                p.screenshot(self.screenshot, scale=2)
            p.quit()
            return
        pressed = {key for key in ("R", "SPACE", "P") if p.btnp(getattr(p, "KEY_" + key))}
        held = {key for key in ("LEFT", "RIGHT", "UP", "DOWN") if p.btn(getattr(p, "KEY_" + key))}
        self.world.control(pressed, held)

    def draw(self):
        p, w = self.pyxel, self.world
        f = w.flight
        p.cls(1)
        p.rect(32, 32, 320, 200, 3)
        for x in range(40, 350, 16):
            for y in range(42, 230, 16):
                p.pset(x, y, 5)
        for wall in w.level.walls:
            x, y, xx, yy = wall.box
            p.rect(x * 2, y * 2, (xx - x) * 2, (yy - y) * 2, 13 if wall.mirror else 4)
            if wall.mirror:
                p.rect(x * 2, yy * 2 - 4, (xx - x) * 2, 4, 7)
                for a in range(int(x * 2), int(xx * 2), 12):
                    p.line(a, yy * 2 - 10, a + 5, yy * 2 - 5, 6)
            else:
                for b in range(int(y * 2) + 4, int(yy * 2), 10):
                    p.line(x * 2, b, xx * 2 - 1, b, 9)
        tx, ty = (value * 2 for value in w.level.target)
        p.rect(tx - 14, ty - 14, 29, 29, 8)
        p.circ(tx, ty, w.level.radius * 2 + 2, 7)
        p.circ(tx, ty, w.level.radius * 2, 0)
        p.text(tx - 12, ty - 26, "TARGET", 7)
        p.text(42, 39, MIRROR_LABEL, 6)
        sx, sy = (value * 2 for value in w.level.start)
        angle = math.radians(w.angle if w.shot_angle is None else w.shot_angle)
        ex, ey = sx + 28 * math.cos(angle), sy + 28 * math.sin(angle)
        p.circ(sx, sy, 9, 5)
        p.line(sx, sy, ex, ey, 10)
        for sign in (-1, 1):
            p.line(ex, ey, ex - 8 * math.cos(angle + sign * 0.45), ey - 8 * math.sin(angle + sign * 0.45), 10)
        p.text(sx - 10, sy + 17, "START", 6)
        if f:
            points = f.trace + [f.pos]
            for a, b in zip(points, points[1:]):
                p.line(a[0] * 2, a[1] * 2, b[0] * 2, b[1] * 2, 6)
            for x, y in f.trace[1:]:
                p.circb(x * 2, y * 2, 4, 10)
            if f.status == "delivered":
                p.circb(tx, ty, 19, 10)
                p.line(tx - 6, ty, tx - 1, ty + 5, 10)
                p.line(tx - 1, ty + 5, tx + 8, ty - 6, 10)
            elif f.status in ("wall", "twice", "outside"):
                x, y = f.pos[0] * 2, f.pos[1] * 2
                p.line(x - 5, y - 5, x + 5, y + 5, 8)
                p.line(x - 5, y + 5, x + 5, y - 5, 8)
        px, py = (f.pos if f and f.status in ("flying", "aimed") else w.level.start)
        p.rect(px * 2 - 5, py * 2 - 3, 11, 7, 10)
        p.rectb(px * 2 - 5, py * 2 - 3, 11, 7, 7)
        p.line(px * 2 - 5, py * 2 - 3, px * 2, py * 2 + 1, 9)
        p.line(px * 2 + 5, py * 2 - 3, px * 2, py * 2 + 1, 9)
        p.rect(0, 0, 384, 20, 1)
        p.text(12, 7, f"REFLECTION MAIL / {STAGE}/5 / {STAGE_TITLE}", 7)
        p.rect(0, 256, 384, 104, 1)
        status = "AIM: ONE SHOT PER TRY" if f is None else {
            "aimed": "LOCKED: DIRECTION SAVED", "flying": "FLYING",
            "delivered": "DELIVERED!", "wall": "STOP: WALL",
            "twice": "STOP: SECOND MIRROR", "outside": "STOP: OUTSIDE / 6 SECONDS",
        }[f.status]
        if w.paused:
            status = "PAUSED"
        p.text(12, 267, status, 10)
        p.text(12, 282, f"ANGLE {w.angle:+07.2f}   TIME {f.age if f else 0:04.2f}s   BOUNCES {f.bounces if f else 0}/1", 7)
        p.text(12, 296, NOTE, 6)
        p.text(12, 314, "LEFT/RIGHT: AIM   UP/DOWN: FINE   SPACE: SEND", 7)
        p.text(12, 328, "R: RETRY   ESC: QUIT" + ("   P: PAUSE" if STAGE == 5 else ""), 6)
        p.text(12, 345, "MODEL: PIXELS / SECONDS / ONE DELIVERY", 5)
        self.draws += 1


def main(headless=False, screenshot=None, checkpoint=False):
    import pyxel

    pyxel.init(384, 360, title=f"Reflection Mail - Stage {STAGE}", fps=FPS, headless=headless)
    app = App(pyxel, headless, screenshot, checkpoint)
    pyxel.run(app.update, app.draw)


if __name__ == "__main__":
    import argparse

    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("--headless-smoke", action="store_true", help="render 12 frames and quit")
    parser.add_argument("--screenshot", help="PNG path, requires --headless-smoke")
    parser.add_argument("--demo-checkpoint", action="store_true", help="synthetic model outcome for QA, not human play")
    args = parser.parse_args()
    if args.screenshot and not args.headless_smoke:
        parser.error("--screenshot requires --headless-smoke")
    main(args.headless_smoke, args.screenshot, args.demo_checkpoint)