'use client';

import { useState, useEffect } from 'react';
import { getTodayISOString } from './dateUtils';

export interface GameState {
    date: string;
    guesses: string[]; // Array of song titles or IDs guessed
    isSolved: boolean;
    isFailed: boolean;
    lastPlayed: number; // Timestamp
    score: number;
    replayCount: number;
    skipCount: number;
    scoreBreakdown: Array<{ value: number; reason: string }>;
    yearGuessed: boolean;
}

export interface Statistics {
    solvedIn1: number;
    solvedIn2: number;
    solvedIn3: number;
    solvedIn4: number;
    solvedIn5: number;
    solvedIn6: number;
    solvedIn7: number;
    failed: number;
}

const STORAGE_KEY_PREFIX = 'hoerdle_game_state';
const STATS_KEY_PREFIX = 'hoerdle_statistics';

const INITIAL_SCORE = 90;

export function useGameState(genre: string | null = null, maxAttempts: number = 7) {
    const [gameState, setGameState] = useState<GameState | null>(null);
    const [statistics, setStatistics] = useState<Statistics | null>(null);

    const getStorageKey = () => genre ? `${STORAGE_KEY_PREFIX}_${genre}` : STORAGE_KEY_PREFIX;
    const getStatsKey = () => genre ? `${STATS_KEY_PREFIX}_${genre}` : STATS_KEY_PREFIX;

    const createNewState = (date: string): GameState => ({
        date,
        guesses: [],
        isSolved: false,
        isFailed: false,
        lastPlayed: Date.now(),
        score: INITIAL_SCORE,
        replayCount: 0,
        skipCount: 0,
        scoreBreakdown: [{ value: INITIAL_SCORE, reason: 'Start value' }],
        yearGuessed: false
    });

    useEffect(() => {
        // Load game state
        const storageKey = getStorageKey();
        const stored = localStorage.getItem(storageKey);
        const today = getTodayISOString();

        if (stored) {
            const parsed = JSON.parse(stored);
            if (parsed.date === today) {
                // Migration for existing states without score
                if (parsed.score === undefined) {
                    parsed.score = INITIAL_SCORE;
                    parsed.replayCount = 0;
                    parsed.skipCount = 0;
                    parsed.scoreBreakdown = [{ value: INITIAL_SCORE, reason: 'Start value' }];
                    parsed.yearGuessed = false;

                    // Retroactively deduct points for existing guesses if possible, 
                    // but simpler to just start at 90 for active games to avoid confusion
                }
                setGameState(parsed as GameState);
            } else {
                // New day
                const newState = createNewState(today);
                setGameState(newState);
                localStorage.setItem(storageKey, JSON.stringify(newState));
            }
        } else {
            // No state
            const newState = createNewState(today);
            setGameState(newState);
            localStorage.setItem(storageKey, JSON.stringify(newState));
        }

        // Load statistics
        const statsKey = getStatsKey();
        const storedStats = localStorage.getItem(statsKey);
        if (storedStats) {
            const parsedStats = JSON.parse(storedStats);
            // Migration for existing stats without solvedIn7
            if (parsedStats.solvedIn7 === undefined) {
                parsedStats.solvedIn7 = 0;
            }
            setStatistics(parsedStats);
        } else {
            const newStats: Statistics = {
                solvedIn1: 0,
                solvedIn2: 0,
                solvedIn3: 0,
                solvedIn4: 0,
                solvedIn5: 0,
                solvedIn6: 0,
                solvedIn7: 0,
                failed: 0,
            };
            setStatistics(newStats);
            localStorage.setItem(statsKey, JSON.stringify(newStats));
        }
    }, [genre]); // Re-run when genre changes

    const saveState = (newState: GameState) => {
        setGameState(newState);
        localStorage.setItem(getStorageKey(), JSON.stringify(newState));
    };

    const updateStatistics = (attempts: number, solved: boolean) => {
        if (!statistics) return;

        const newStats = { ...statistics };

        if (solved) {
            switch (attempts) {
                case 1: newStats.solvedIn1++; break;
                case 2: newStats.solvedIn2++; break;
                case 3: newStats.solvedIn3++; break;
                case 4: newStats.solvedIn4++; break;
                case 5: newStats.solvedIn5++; break;
                case 6: newStats.solvedIn6++; break;
                case 7: newStats.solvedIn7++; break;
                default:
                    break;
            }
        } else {
            newStats.failed++;
        }

        setStatistics(newStats);
        localStorage.setItem(getStatsKey(), JSON.stringify(newStats));
    };

    const addGuess = (guess: string, correct: boolean) => {
        if (!gameState) return;

        const newGuesses = [...gameState.guesses, guess];
        const isSolved = correct;
        const isFailed = !correct && newGuesses.length >= maxAttempts;

        let newScore = gameState.score;
        const newBreakdown = [...gameState.scoreBreakdown];

        if (correct) {
            newScore += 20;
            newBreakdown.push({ value: 20, reason: 'Correct Answer' });
        } else {
            if (guess === 'SKIPPED') {
                newScore -= 5;
                newBreakdown.push({ value: -5, reason: 'Skip' });
            } else {
                newScore -= 3;
                newBreakdown.push({ value: -3, reason: 'Wrong guess' });
            }
        }

        // If failed, reset score to 0
        if (isFailed) {
            if (newScore > 0) {
                newBreakdown.push({ value: -newScore, reason: 'Game Over' });
                newScore = 0;
            }
        }

        // Ensure score doesn't go below 0
        newScore = Math.max(0, newScore);

        const newState = {
            ...gameState,
            guesses: newGuesses,
            isSolved,
            isFailed,
            lastPlayed: Date.now(),
            score: newScore,
            scoreBreakdown: newBreakdown,
            // Update skip count if skipped
            skipCount: guess === 'SKIPPED' ? gameState.skipCount + 1 : gameState.skipCount
        };

        saveState(newState);

        // Update statistics when game ends
        if (isSolved || isFailed) {
            updateStatistics(newGuesses.length, isSolved);
        }
    };

    const giveUp = () => {
        if (!gameState || gameState.isSolved || gameState.isFailed) return;

        let newScore = 0;
        const newBreakdown = [...gameState.scoreBreakdown];

        if (gameState.score > 0) {
            newBreakdown.push({ value: -gameState.score, reason: 'Gave Up' });
        }

        const newState = {
            ...gameState,
            isFailed: true,
            score: 0,
            scoreBreakdown: newBreakdown,
            lastPlayed: Date.now()
        };
        saveState(newState);
        updateStatistics(gameState.guesses.length, false);
    };

    const addReplay = () => {
        if (!gameState || gameState.isSolved || gameState.isFailed) return;

        let newScore = gameState.score - 1;
        // Ensure score doesn't go below 0
        newScore = Math.max(0, newScore);

        const newBreakdown = [...gameState.scoreBreakdown, { value: -1, reason: 'Replay snippet' }];

        const newState = {
            ...gameState,
            replayCount: gameState.replayCount + 1,
            score: newScore,
            scoreBreakdown: newBreakdown
        };
        saveState(newState);
    };

    const addYearBonus = (correct: boolean) => {
        if (!gameState) return;

        let newScore = gameState.score;
        const newBreakdown = [...gameState.scoreBreakdown];

        if (correct) {
            newScore += 10;
            newBreakdown.push({ value: 10, reason: 'Bonus: Correct Year' });
        } else {
            newBreakdown.push({ value: 0, reason: 'Bonus: Wrong Year' });
        }

        const newState = {
            ...gameState,
            score: newScore,
            scoreBreakdown: newBreakdown,
            yearGuessed: true
        };
        saveState(newState);
    };

    const skipYearBonus = () => {
        if (!gameState) return;

        const newBreakdown = [...gameState.scoreBreakdown, { value: 0, reason: 'Bonus: Skipped' }];

        const newState = {
            ...gameState,
            scoreBreakdown: newBreakdown,
            yearGuessed: true
        };
        saveState(newState);
    };

    return { gameState, statistics, addGuess, giveUp, addReplay, addYearBonus, skipYearBonus };
}