// --- Constants ---
export const MAX_HP = 20;
export const MAX_UNDO_STEPS = 1;
export const STORAGE_KEY = 'scoundrel_state_v1';

export const SUITS = {
    HEARTS: { symbol: '♥', color: 'red', type: 'POTION' },
    DIAMONDS: { symbol: '♦', color: 'red', type: 'WEAPON' },
    CLUBS: { symbol: '♣', color: 'black', type: 'MONSTER' },
    SPADES: { symbol: '♠', color: 'black', type: 'MONSTER' }
};

export const RANKS = ['2', '3', '4', '5', '6', '7', '8', '9', '10', 'J', 'Q', 'K', 'A'];

export const THEMES = {
    'Text': { label: 'Classic (Text)' },
    'SimpleSVG': { label: 'Simple SVG', ext: 'svg', path: 'assets/themes/SimpleSVG' }
};

export const INITIAL_STATE = {
    hp: 20,
    max_hp: 20,
    deck: [],
    room: [null, null, null, null], // Fixed indices
    discard_pile: [],
    defeated_monsters: [],
    weapon: null,
    last_enemy_value: Infinity,
    cards_played_this_turn: 0,
    potion_used_this_turn: false,
    can_flee: true,
    game_over: false,
    won: false,
    fled_last_turn: false,
    msg: "Welcome to the dungeon.",
    theme: 'Text',
    history: []
};

// --- Helpers ---
export const getCardValue = (rank) => {
    if (rank === 'A') return 14;
    if (rank === 'K') return 13;
    if (rank === 'Q') return 12;
    if (rank === 'J') return 11;
    return parseInt(rank, 10);
};

export const createDeck = () => {
    let deck = [];
    let id_counter = 0;
    for (const [suit_key, suit_data] of Object.entries(SUITS)) {
        for (const rank of RANKS) {
            if ((suit_key === 'HEARTS' || suit_key === 'DIAMONDS') && ['J', 'Q', 'K', 'A'].includes(rank)) continue;
            deck.push({
                id: `card-${id_counter++}`,
                suit: suit_data.symbol,
                color: suit_data.color,
                type: suit_data.type,
                rank: rank,
                value: getCardValue(rank),
                suit_key: suit_key
            });
        }
    }
    return deck;
};

export const shuffleDeck = (deck) => {
    const new_deck = [...deck];
    for (let i = new_deck.length - 1; i > 0; i--) {
        const j = Math.floor(Math.random() * (i + 1));
        [new_deck[i], new_deck[j]] = [new_deck[j], new_deck[i]];
    }
    return new_deck;
};

export const saveHistory = (currentState) => {
    // Deep copy state excluding history itself to avoid recursion/heavy memory usage
    const { history, ...stateToSave } = currentState;
    // Basic deep copy for this simple state structure (arrays/objects)
    const snapshot = JSON.parse(JSON.stringify(stateToSave));
    // Limit history to MAX_UNDO_STEPS
    return [...history, snapshot].slice(-MAX_UNDO_STEPS);
};

export const saveState = (state) => {
    try {
        // Convert Infinity to a placeholder string for JSON serialization
        const serialized = JSON.stringify(state, (key, value) => {
            return value === Infinity ? '___Infinity___' : value;
        });
        localStorage.setItem(STORAGE_KEY, serialized);
    } catch (e) {
        console.error("Failed to save state:", e);
    }
};

export const loadState = () => {
    try {
        const saved = localStorage.getItem(STORAGE_KEY);
        if (!saved) return null;
        return JSON.parse(saved, (key, value) => {
            return value === '___Infinity___' ? Infinity : value;
        });
    } catch (e) {
        console.error("Failed to load state:", e);
        return null;
    }
};