// gameMode.js - Central coordinator: switches between World and Workshop modes
import { worldState, setPlayerPosition, warpToMap, isPuzzleSolved, solvePuzzle, startDialog } from './worldState.js';
import { initWorldRenderer, startWorldLoop, stopWorldLoop } from './worldRenderer.js';
import { initWorldInput, destroyWorldInput, setInteractionHandler } from './worldInput.js';
import { getMap } from './maps.js';
import { saveGadget, openBackpack, getGadgets, openNamingScreen, showNotification } from './inventory.js';

// Circuit editor stop function (to stop its render loop when switching modes)
import { stopCircuitLoop } from '../renderer.js';
import { state as circuitState } from '../state.js';

// Circuit editor modules (registered from app.js to avoid circular deps)
let circuitEditorInit = null;
let circuitEditorDestroy = null;

let currentMode = 'none'; // 'world' | 'workshop'

/**
 * Register the circuit editor's init/destroy functions.
 * Called from app.js so we don't create circular imports.
 */
export function registerCircuitEditor(initFn, destroyFn) {
    circuitEditorInit = initFn;
    circuitEditorDestroy = destroyFn;
}

/**
 * Boot the game — start in world mode
 */
export function startGame() {
    // Set spawn
    const map = getMap(worldState.currentMap);
    if (map && map.spawn) {
        setPlayerPosition(map.spawn.x, map.spawn.y);
    }

    // Wire up interaction handler
    setInteractionHandler(handleInteraction);

    // Wire save-gadget button
    const saveGadgetBtn = document.getElementById('save-gadget-btn');
    if (saveGadgetBtn) {
        saveGadgetBtn.addEventListener('click', handleSaveGadget);
    }

    // Enter world mode
    enterWorldMode();
}

// ==================== Mode switching ====================

export function enterWorldMode() {
    if (currentMode === 'world') return;

    // Tear down workshop if active
    if (currentMode === 'workshop') {
        stopCircuitLoop();
        if (circuitEditorDestroy) circuitEditorDestroy();
        hideWorkshopUI();
    }

    currentMode = 'world';
    worldState.mode = 'world';

    showWorldUI();
    initWorldRenderer();
    initWorldInput();
    startWorldLoop();

    console.log('[gameMode] entered world mode');
}

export function enterWorkshopMode() {
    if (currentMode === 'workshop') return;

    // Tear down world
    if (currentMode === 'world') {
        stopWorldLoop();
        destroyWorldInput();
        hideWorldUI();
    }

    currentMode = 'workshop';
    worldState.mode = 'workshop';

    showWorkshopUI();
    if (circuitEditorInit) circuitEditorInit();

    console.log('[gameMode] entered workshop mode');
}

export function getCurrentMode() { return currentMode; }

// ==================== Interaction handler ====================

function handleInteraction(event) {
    switch (event.type) {
        case 'enterWorkshop':
            enterWorkshopMode();
            break;

        case 'puzzleDoor': {
            const inter = event.data;
            if (isPuzzleSolved(inter.puzzleId)) {
                startDialog(['This door is already unlocked.'], 'System');
                return;
            }
            // Open backpack to let player choose a gadget
            const gadgets = getGadgets();
            if (gadgets.length === 0) {
                startDialog([
                    'This door requires a logic circuit to open.',
                    `Required output: [${inter.requiredOutputs.join(', ')}]`,
                    'Craft a circuit in your Workshop (TAB) and save it as a gadget!'
                ], 'System');
                return;
            }
            // Open backpack with a "use" callback that tests the gadget
            openBackpack((gadget) => {
                const result = testGadgetOnPuzzle(gadget, inter);
                if (result) {
                    solvePuzzle(inter.puzzleId);
                    startDialog([
                        `🎉 "${gadget.name}" solved the puzzle!`,
                        'The door unlocks with a satisfying click.'
                    ], 'System');
                } else {
                    startDialog([
                        `"${gadget.name}" didn't produce the right output.`,
                        `Required: [${inter.requiredOutputs.join(', ')}]`,
                        'Try a different gadget or tweak your circuit!'
                    ], 'System');
                }
            });
            break;
        }

        case 'mapExit': {
            // Every exit MUST have targetX/targetY — bidirectional door links.
            // No spawn fallback. Spawn is only for the initial game start.
            const { targetMap, targetX, targetY } = event.data;
            warpToMap(targetMap, targetX, targetY);
            console.log(`[gameMode] warped to ${targetMap} (${targetX}, ${targetY})`);
            break;
        }

        case 'openInventory':
            // TODO: inventory UI
            console.log('[gameMode] inventory:', worldState.inventory);
            break;
    }
}

// ==================== Save Gadget ====================

function handleSaveGadget() {
    // Gather current circuit from the editor state
    const gates = circuitState.gates;
    const connections = circuitState.connections;

    const inputGates = gates.filter(g => g.type === 'INPUT');
    const outputGates = gates.filter(g => g.type === 'OUTPUT');

    if (inputGates.length === 0 || outputGates.length === 0) {
        showNotification('Need at least 1 INPUT and 1 OUTPUT!', '⚠️', '#ff5555');
        return;
    }

    // Switch to world render temporarily to show the naming screen on canvas
    // (workshop mode uses its own render loop, so we overlay on the canvas)
    openNamingScreen(
        '🎒 Name your gadget',
        `Gadget ${getGadgets().length + 1}`,
        (name) => {
            if (!name) return; // cancelled

            const component = {
                id: name.toLowerCase().replace(/[^a-z0-9_]/g, '_').replace(/_+/g, '_'),
                name,
                inputCount: inputGates.length,
                outputCount: outputGates.length,
                inputIds: inputGates.map(g => g.id),
                outputIds: outputGates.map(g => g.id),
                gates: JSON.parse(JSON.stringify(gates)),
                connections: JSON.parse(JSON.stringify(connections))
            };

            const result = saveGadget(component);
            if (result.success) {
                showNotification(`"${name}" saved to backpack!`, '🎒', '#ff44aa');
            } else {
                showNotification(result.error, '⚠️', '#ff5555');
            }
        }
    );
}

// ==================== Puzzle testing ====================

/**
 * Test a gadget against a puzzle door's required outputs.
 * Runs the gadget's internal circuit with all possible input combos
 * and checks if outputs match.
 */
function testGadgetOnPuzzle(gadget, puzzleInter) {
    const required = puzzleInter.requiredOutputs;
    if (!required || !gadget.gates || !gadget.connections) return false;

    // Clone internal circuit for evaluation
    const gates = JSON.parse(JSON.stringify(gadget.gates));
    const conns = gadget.connections;
    const inputIds = gadget.inputIds || [];
    const outputIds = gadget.outputIds || [];

    // Test with all inputs = 0, then all = 1, etc.
    // For simplicity: test all 2^n input combos and collect outputs for each
    const n = inputIds.length;
    const allOutputs = [];

    for (let combo = 0; combo < (1 << n); combo++) {
        // Reset gates
        const evalGates = JSON.parse(JSON.stringify(gates));

        // Set inputs
        for (let i = 0; i < n; i++) {
            const inputGate = evalGates.find(g => g.id === inputIds[i]);
            if (inputGate) inputGate.value = (combo >> i) & 1;
        }

        // Evaluate (fixed-point iteration)
        for (let iter = 0; iter < 20; iter++) {
            let changed = false;
            for (const g of evalGates) {
                if (g.type === 'INPUT' || g.type === 'CLOCK') continue;
                const inCount = g.type === 'NOT' || g.type === 'OUTPUT' ? 1 : 2;
                const gInputs = [];
                for (let j = 0; j < inCount; j++) {
                    const conn = conns.find(c => c.to === g.id && c.toPort === j);
                    if (conn) {
                        const src = evalGates.find(s => s.id === conn.from);
                        gInputs.push(src ? (src.value || 0) : 0);
                    } else {
                        gInputs.push(0);
                    }
                }
                let result = 0;
                switch (g.type) {
                    case 'AND':    result = (gInputs[0] && gInputs[1]) ? 1 : 0; break;
                    case 'OR':     result = (gInputs[0] || gInputs[1]) ? 1 : 0; break;
                    case 'NOT':    result = gInputs[0] ? 0 : 1; break;
                    case 'NAND':   result = (gInputs[0] && gInputs[1]) ? 0 : 1; break;
                    case 'NOR':    result = (gInputs[0] || gInputs[1]) ? 0 : 1; break;
                    case 'XOR':    result = (gInputs[0] !== gInputs[1]) ? 1 : 0; break;
                    case 'OUTPUT': result = gInputs[0] || 0; break;
                    default:       result = 0;
                }
                if (result !== g.value) { g.value = result; changed = true; }
            }
            if (!changed) break;
        }

        // Collect outputs
        for (const outId of outputIds) {
            const outGate = evalGates.find(g => g.id === outId);
            allOutputs.push(outGate ? (outGate.value || 0) : 0);
        }
    }

    // Compare: the required outputs should match the output pattern
    // Simple comparison: check if required matches any combo's outputs
    // Or: required is the full truth table (outputs for combo 0, then combo 1, etc.)
    if (allOutputs.length === required.length) {
        return allOutputs.every((v, i) => v === required[i]);
    }

    // Fallback: check if any single combo's outputs match
    const outPerCombo = outputIds.length;
    for (let combo = 0; combo < (1 << n); combo++) {
        const comboOutputs = allOutputs.slice(combo * outPerCombo, (combo + 1) * outPerCombo);
        if (comboOutputs.length === required.length && comboOutputs.every((v, i) => v === required[i])) {
            return true;
        }
    }

    return false;
}

// ==================== UI visibility ====================

function showWorldUI() {
    // Hide workshop-specific elements
    const toolbar = document.getElementById('toolbar');
    const wavePanel = document.getElementById('waveform-panel');
    const canvas = document.getElementById('canvas');

    if (toolbar) toolbar.style.display = 'none';
    if (wavePanel) wavePanel.style.display = 'none';
    if (canvas) {
        canvas.style.top = '0';
        canvas.style.cursor = 'default';
    }

    // Hide game buttons (we're IN world, not workshop)
    const backBtn = document.getElementById('back-to-world-btn');
    if (backBtn) backBtn.style.display = 'none';
    const saveBtn = document.getElementById('save-gadget-btn');
    if (saveBtn) saveBtn.style.display = 'none';
}

function hideWorldUI() {
    // Nothing special to hide — canvas stays
}

function showWorkshopUI() {
    const toolbar = document.getElementById('toolbar');
    const canvas = document.getElementById('canvas');

    if (toolbar) toolbar.style.display = 'flex';
    if (canvas) {
        canvas.style.top = '56px';
        canvas.style.cursor = 'default';
    }

    // Move game buttons into toolbar-right so they sit inline with Export/Import
    const toolbarRight = document.querySelector('.toolbar-right');
    const saveBtn = document.getElementById('save-gadget-btn');
    const backBtn = document.getElementById('back-to-world-btn');
    if (toolbarRight && saveBtn) {
        toolbarRight.insertBefore(saveBtn, toolbarRight.firstChild);
        saveBtn.style.display = 'inline-block';
    }
    if (toolbarRight && backBtn) {
        toolbarRight.insertBefore(backBtn, toolbarRight.firstChild);
        backBtn.style.display = 'inline-block';
    }
}

function hideWorkshopUI() {
    const toolbar = document.getElementById('toolbar');
    if (toolbar) toolbar.style.display = 'none';

    // Hide game buttons and move them back out of toolbar
    const backBtn = document.getElementById('back-to-world-btn');
    if (backBtn) { backBtn.style.display = 'none'; document.body.insertBefore(backBtn, document.body.firstChild); }
    const saveBtn = document.getElementById('save-gadget-btn');
    if (saveBtn) { saveBtn.style.display = 'none'; document.body.insertBefore(saveBtn, document.body.firstChild); }
}