# -*- coding: utf-8 -*-
"""030 ひと箱の天気 / standalone tutorial / fictional discrete water model.
Original model: Pyxel 100 contributors. Teaching adaptation: 2026.
No external image/font asset is needed. Pyxel is imported only in main().
"""
# 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:
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# The above copyright notice and this permission notice shall be included in all
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# 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
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# SOFTWARE.
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# The bundled Noto-derived bitmap glyphs are separately licensed under SIL OFL.
# See assets/NOTO-LICENSE.txt.

from dataclasses import dataclass, replace, asdict
import hashlib, json

STAGE = 2
STAGE_TITLE = 'VERTICAL VISIBILITY'
GUIDE = 'LEFT/RIGHT: cloud  1/2/3: presets  UP/DOWN: S column only'

@dataclass(frozen=True)
class Node:
    name:str
    x:int
    y:int
    kind:str='dish'
    capacity:int=0
    target:str|None=None
    alternate:str|None=None
    catches:bool=True
    shades:bool=False

@dataclass(frozen=True)
class Level:
    title:str
    nodes:tuple[Node,...]
    start:tuple[int,...]
    total:int
    gate_linked:bool=True
    width:int=7
    cloud_capacity:int=3

@dataclass(frozen=True)
class State:
    x:int
    cloud:int
    water:tuple[int,...]
    absorbed:int=0  # Explicit accounting slot; authored soil holds water, never absorbs it.
    moves:int=0

@dataclass(frozen=True)
class Result:
    state:State
    accepted:bool
    reason:str
    trace:tuple[tuple[int,...],...]=()
    transfers:tuple[tuple[tuple[str,str,int],...],...]=()

# 原作Cの座標・容量・流路。列は0〜6、yは下へ増える。
BOARD = Level('C: keep one drop in K', (
    Node('S',1,5,capacity=3),
    Node('F',5,4,capacity=2,target='S'),
    Node('K',3,5,capacity=1,target='S'),
    Node('gate',5,2,'gate',target='F',alternate='S',shades=True),
), (3,0,0,0), 3)

def index(level,name):return next(i for i,n in enumerate(level.nodes) if n.name==name)

def amount(level,state,name):return state.water[index(level,name)]

def initial(level):return State(1,0,level.start)

def total(state):return state.cloud+sum(state.water)+state.absorbed

def check(level,state,stable=True):
    assert len(state.water)==len(level.nodes)
    assert 0<=state.x<level.width and 0<=state.cloud<=level.cloud_capacity
    assert state.absorbed>=0 and all(v>=0 for v in state.water)
    assert total(state)==level.total
    if stable:
        assert all(v<=n.capacity if n.kind=='dish' else v==0 for n,v in zip(level.nodes,state.water))

def state_hash(state):return hashlib.sha256(json.dumps(asdict(state),sort_keys=True).encode('utf-8')).hexdigest()

def source_exchange(level, state, action):
    """01/02の実験: Sの真上だけで所有者を1滴ずつ交換する。"""
    if action not in ('U','D'):
        return Result(state,False,'unused')
    if state.x != 1:
        return Result(state,False,'inspect_only')
    i = index(level,'S')
    water = list(state.water)
    if action == 'U':
        if state.cloud == level.cloud_capacity:
            return Result(state,False,'full')
        if water[i] == 0:
            return Result(state,False,'dry')
        water[i] -= 1
        cloud = state.cloud + 1
    else:
        if state.cloud == 0:
            return Result(state,False,'empty')
        water[i] += 1
        cloud = state.cloud - 1
    new = replace(state,cloud=cloud,water=tuple(water),moves=state.moves+1)
    check(level,new)
    return Result(new,True,'sun' if action=='U' else 'rain')

def gate_open(level,water):
    return not level.gate_linked or not any(n.name=='K' for n in level.nodes) or water[index(level,'K')]>=1

def visible(level,state,sun=False):
    candidates=[]
    for i,n in enumerate(level.nodes):
        if n.x!=state.x:continue
        if n.kind=='gate' and gate_open(level,state.water):continue
        if (sun and (n.kind=='dish' or n.shades)) or (not sun and n.catches):candidates.append((n.y,n.name,i))
    return min(candidates)[2] if candidates else None

def preview(level,state):
    sun=visible(level,state,True);rain=visible(level,state)
    rain=index(level,'S') if rain is None else rain
    return sun,rain

def survey_state(number):
    # 原作の到達状態: 初期 / UUURRD / UUURRDRRD。
    return (initial(BOARD), State(3,2,(0,0,1,0),moves=6),
            State(5,1,(0,1,1,0),moves=9))[number-1]

CONTROLS = ('LEFT','RIGHT','UP','DOWN','X','Z','R','1','2','3')
REPLAY = {'L':'LEFT','R':'RIGHT','U':'UP','D':'DOWN','X':'X','Z':'Z',
          'Q':'R','1':'1','2':'2','3':'3'}

class Controller:
    def __init__(self):
        self.lock = False
        self.reset()

    def reset(self):
        self.level = BOARD
        self.state = initial(BOARD)
        self.history = []
        self.trace = ()
        self.transfers = ()
        self.tick_count = 0
        self.reason = 'ready'
        self.preset = 1
        
        # reset中にlockは消さない。R後も全キー解放が必要。

    def tick(self, pressed=(), held=()):
        pressed = set(pressed) & set(CONTROLS)
        held = set(held) & set(CONTROLS)
        if self.lock:
            if not held:
                self.lock = False
            return
        if not pressed and len(held) <= 1:
            return
        if len(pressed) != 1 or pressed != held:
            self.lock = True
            self.reason = 'chord_rejected'
            return
        self.lock = True
        key = next(iter(pressed))
        if key == 'R':
            self.reset()
            return
        if key in ('1','2','3'):
            self.preset=int(key);self.state=survey_state(self.preset);self.reason='preset';return
        if key in ('LEFT','RIGHT'):
            x=self.state.x+(-1 if key=='LEFT' else 1)
            if 0<=x<self.level.width:
                self.state=replace(self.state,x=x,moves=self.state.moves+1);self.reason='move'
            else:self.reason='edge'
            return
        r=source_exchange(self.level,self.state,{'UP':'U','DOWN':'D'}.get(key,'?'))
        self.state=r.state;self.reason=r.reason

    def snapshot(self):
        sun, rain = preview(self.level,self.state) if STAGE >= 2 else (None,None)
        return {'state':asdict(self.state),'hash':state_hash(self.state),
                'total':total(self.state),'budget':self.level.total,
                'gate_open':gate_open(self.level,self.state.water) if STAGE>=2 else False,
                'won':won(self.level,self.state) if STAGE>=4 else False,
                'sun':None if sun is None else self.level.nodes[sun].name,
                'rain':None if rain is None else self.level.nodes[rain].name,
                'event':self.reason,'history_depth':len(self.history),
                'trace':self.trace,'transfers':self.transfers,
                'ticks':self.tick_count,'preset':self.preset,'lock':self.lock}

def draw_board(p,c):
    """描画は状態を読むだけ。水滴の絵を別資源として加算しない。"""
    s=c.state; level=c.level; snap=c.snapshot()
    p.cls(1)
    p.text(14,12,'BOX WEATHER / STEP '+str(STAGE)+' / '+STAGE_TITLE,10)
    p.text(14,27,'Fictional integer water model / no automatic evaporation / silent',6)
    ox,oy,dx,dy=47,105,54,42
    def xy(n): return ox+n.x*dx,oy+n.y*dy
    def arrow(x,y,xx,yy,color):
        p.line(x,y,xx,yy,color)
        if abs(xx-x)>abs(yy-y):
            sign=1 if xx>x else -1
            p.line(xx,yy,xx-sign*5,yy-3,color);p.line(xx,yy,xx-sign*5,yy+3,color)
        else:
            sign=1 if yy>y else -1
            p.line(xx,yy,xx-3,yy-sign*5,color);p.line(xx,yy,xx+3,yy-sign*5,color)
    p.rect(18,47,402,313,0);p.rectb(18,47,402,313,5)
    for x in range(7):
        p.text(ox+x*dx-2,53,str(x),13)
        for y in range(110,333,10): p.pset(ox+x*dx,y,1)
    for n in level.nodes:
        if n.target:
            dst=level.nodes[index(level,n.target)]
            x,y=xy(n);xx,yy=xy(dst)
            if n.kind!='dish':
                color=(11 if snap['gate_open'] else 5) if n.kind=='gate' else 6
                arrow(x,y+12,xx,yy-15,color)
        if n.kind=='gate':
            x,y=xy(n);color=5 if snap['gate_open'] else 6
            arrow(x+25,y,401,y,color);arrow(401,y,401,346,color)
    src=level.nodes[index(level,'S')];sx,sy=xy(src)
    arrow(401,346,sx,346,6);arrow(sx,346,sx,sy+13,6)
    p.text(190,349,'RETURN TO S',6)
    for i,n in enumerate(level.nodes):
        x,y=xy(n);value=s.water[i]
        if n.kind=='dish':
            p.rect(x-21,y-9,43,19,4);p.rect(x-18,y-10,37,14,1)
            for j in range(n.capacity):
                if j<value:p.circ(x-12+j*9,y-2,3,12)
                else:p.circb(x-12+j*9,y-2,3,5)
            p.text(x-22,y+16,f'{n.name}: {value}/{n.capacity}',7)
            if value>n.capacity: p.text(x-22,y+27,'EXCESS '+str(value-n.capacity),8)
            if n.name=='F':
                p.line(x,y-12,x,y-28,11);p.circ(x,y-30,5,10 if snap['won'] else 3)
        else:
            color=11 if n.kind=='gate' and snap['gate_open'] else 9
            p.rectb(x-23,y-10,47,20,color)
            p.text(x-20,y-3,n.name,7)
            p.text(x-21,y+15,'WATER '+str(value),12)
            if n.kind=='gate': p.text(x-20,y-21,'OPEN' if snap['gate_open'] else 'CLOSED',color)
        if n.name==snap['rain']:p.rectb(x-26,y-14,53,29,12)
        if n.name==snap['sun']:p.rectb(x-24,y-12,49,25,10)
    cx=ox+s.x*dx
    p.elli(cx-24,76,49,20,7);p.circ(cx-10,76,11,7);p.circ(cx+9,73,12,7)
    for j in range(level.cloud_capacity):
        if j<s.cloud:p.circ(cx-10+j*10,86,3,12)
        else:p.circb(cx-10+j*10,86,3,5)
    p.rect(437,47,269,313,0)
    lines=[('WATER OWNERS',10),('Cloud: '+str(s.cloud)+' / '+str(level.cloud_capacity),12)]
    lines += [(n.name+': '+str(s.water[i]),7) for i,n in enumerate(level.nodes)]
    lines += [('Absorbed ledger: '+str(s.absorbed),6),
              ('TOTAL '+str(total(s))+' = BUDGET '+str(level.total),11),
              ('Moves: '+str(s.moves)+'   ticks: '+str(c.tick_count),7),
              ('History: '+str(len(c.history)),7)]
    y=60
    for line,color in lines:p.text(450,y,line,color);y+=17
    p.text(450,275,'SUN : '+str(snap['sun']),10)
    p.text(450,292,'RAIN: '+str(snap['rain']),12)
    p.text(450,310,'CASE '+str(c.preset)+' / '+level.title,6)
    p.text(450,332,'WON' if snap['won'] else 'OBSERVE / TRY',10)
    p.text(14,376,'EVENT: '+c.reason,10)
    p.text(14,394,GUIDE,7)
    p.text(14,413,'R: reset  ESC: quit / release ALL controls between presses',6)
    if c.transfers:
        p.text(14,433,'LAST FLOW: '+str(c.transfers[-1]),12)
    else:p.text(14,433,'Blue=rain target  Yellow=sun target  /  x=0..6',13)
    p.text(14,458,'A flow tick sends at most one unit per emitting node. No water is deleted.',6)
    p.text(14,476,'01-03 are labs. 04-05 use original C rules. This is NOT physical hydrology.',13)


def main(headless=False,sequence='',screenshot=None,report=None):
    from pathlib import Path
    import time
    import pyxel  # モデルのimportやstdlibテストにPyxelは不要。
    c=Controller();codes={n:getattr(pyxel,'KEY_'+n) for n in CONTROLS}
    frame=0;events=[];last=max(12,2*len(sequence)+2);start=time.perf_counter()
    def update():
        nonlocal frame
        frame+=1
        if headless:
            i=(frame-1)//2
            if frame%2 and i<len(sequence):
                k=REPLAY[sequence[i]];c.tick((k,),(k,))
                events.append({'input':sequence[i],'snapshot':c.snapshot()})
            else:c.tick()
        else:c.tick([n for n,k in codes.items() if pyxel.btnp(k)],
                    [n for n,k in codes.items() if pyxel.btn(k)])
    def draw():
        draw_board(pyxel,c)
        if headless and frame>=last:
            if screenshot:pyxel.screenshot(str(Path(screenshot).resolve()),scale=1)
            if report:
                Path(report).write_text(json.dumps({
                    'label':'actual Pyxel headless / synthetic controller input / silent',
                    'stage':STAGE,'frames':frame,'logical_seconds':frame/30,
                    'wall_seconds_before_exit':round(time.perf_counter()-start,6),
                    'program_sha256':hashlib.sha256(Path(__file__).read_bytes()).hexdigest(),
                    'sequence':sequence,'events':events,'snapshot':c.snapshot()
                },ensure_ascii=False,indent=2)+'\n',encoding='utf-8')
            pyxel.quit()
    pyxel.init(720,500,title='Box Weather - Step '+str(STAGE),fps=30,headless=headless)
    pyxel.run(update,draw)


if __name__=='__main__':
    import argparse
    parser=argparse.ArgumentParser(description=__doc__)
    group=parser.add_mutually_exclusive_group()
    group.add_argument('--headless-smoke',action='store_true')
    group.add_argument('--headless-replay',help='L/R/U/D arrows; X/Z; Q reset; 1/2/3 presets')
    parser.add_argument('--screenshot');parser.add_argument('--report')
    args=parser.parse_args()
    headless=args.headless_smoke or args.headless_replay is not None
    if not headless and (args.screenshot or args.report):parser.error('Outputs require headless mode')
    seq=args.headless_replay or ''
    if any(k not in REPLAY for k in seq):parser.error('Unsupported replay character')
    main(headless,seq,args.screenshot,args.report)