// worldRenderer.js - Renders the tile-based game world on canvas
import { drawPlayer, drawTile, drawNPC, drawInteractionPrompt, drawDialogBox, TILE_SIZE, SCALE } from './sprites.js';
import { worldState } from './worldState.js';
import { getMap, getTile, getInteraction, getNPC } from './maps.js';
import { updateMovement } from './worldInput.js';

let canvas = null;
let ctx = null;
let animFrameId = null;
let lastTime = 0;

const TILE_PX = TILE_SIZE * SCALE; // 48px per tile on screen

export function initWorldRenderer() {
    canvas = document.getElementById('canvas');
    ctx = canvas.getContext('2d');
    resizeCanvas();
    window.addEventListener('resize', resizeCanvas);
    return true;
}

function resizeCanvas() {
    if (!canvas) return;
    canvas.width = canvas.offsetWidth || window.innerWidth;
    canvas.height = canvas.offsetHeight || window.innerHeight;
}

/** Convert tile coords → screen pixel coords (camera-relative) */
export function worldToScreen(tileX, tileY) {
    const p = worldState.player;
    const cx = canvas.width / 2;
    const cy = canvas.height / 2;
    // Player world position with interpolation
    const pwx = (p.x + p.px) * TILE_PX;
    const pwy = (p.y + p.py) * TILE_PX;
    return {
        x: cx + (tileX * TILE_PX - pwx),
        y: cy + (tileY * TILE_PX - pwy)
    };
}

/** Visible tile range for culling */
function getVisibleBounds() {
    const p = worldState.player;
    const halfW = canvas.width / 2;
    const halfH = canvas.height / 2;
    const pwx = (p.x + p.px) * TILE_PX;
    const pwy = (p.y + p.py) * TILE_PX;
    return {
        minX: Math.floor((pwx - halfW) / TILE_PX) - 1,
        minY: Math.floor((pwy - halfH) / TILE_PX) - 1,
        maxX: Math.ceil((pwx + halfW) / TILE_PX) + 1,
        maxY: Math.ceil((pwy + halfH) / TILE_PX) + 1
    };
}

/** Tile the player is facing */
function getFacingTile() {
    const p = worldState.player;
    let x = p.x, y = p.y;
    if (p.direction === 'up') y--;
    else if (p.direction === 'down') y++;
    else if (p.direction === 'left') x--;
    else if (p.direction === 'right') x++;
    return { x, y };
}

/** Main render frame */
export function renderWorld(timestamp) {
    const dt = (timestamp - lastTime) / 1000;
    lastTime = timestamp;

    // Update movement interpolation
    updateMovement(dt);

    // Resize check
    if (canvas.width !== canvas.offsetWidth || canvas.height !== canvas.offsetHeight) {
        resizeCanvas();
    }

    // Clear
    ctx.fillStyle = '#0a0a0f';
    ctx.fillRect(0, 0, canvas.width, canvas.height);

    const map = getMap(worldState.currentMap);
    if (!map) return;

    const bounds = getVisibleBounds();

    // === Layer 1: Tiles ===
    for (let ty = bounds.minY; ty <= bounds.maxY; ty++) {
        for (let tx = bounds.minX; tx <= bounds.maxX; tx++) {
            const tileType = getTile(worldState.currentMap, tx, ty);
            if (tileType === null) continue;
            const pos = worldToScreen(tx, ty);
            drawTile(ctx, pos.x, pos.y, tileType);
        }
    }

    // === Layer 2: NPCs ===
    if (map.npcs) {
        for (const npc of map.npcs) {
            const pos = worldToScreen(npc.x, npc.y);
            drawNPC(ctx, pos.x, pos.y, npc.type, 0);
        }
    }

    // === Layer 3: Player ===
    const pp = worldToScreen(worldState.player.x + worldState.player.px,
                              worldState.player.y + worldState.player.py);
    // Adjust: worldToScreen already offsets from player, so player is always at center
    const pcx = canvas.width / 2 - TILE_PX / 2;
    const pcy = canvas.height / 2 - TILE_PX / 2;
    const frame = worldState.player.moving ? (Math.floor(Date.now() / 120) % 2) : 0;
    drawPlayer(ctx, pcx, pcy, worldState.player.direction, frame);

    // === Layer 4: Interaction prompt ===
    if (!worldState.dialog && !worldState.player.moving) {
        const ft = getFacingTile();
        const inter = getInteraction(worldState.currentMap, ft.x, ft.y);
        const npc = getNPC(worldState.currentMap, ft.x, ft.y);
        if (inter || npc) {
            const pos = worldToScreen(ft.x, ft.y);
            drawInteractionPrompt(ctx, pos.x, pos.y);
        }
    }

    // === Layer 5: Dialog box ===
    if (worldState.dialog) {
        const line = worldState.dialog.lines[worldState.dialog.currentLine] || '';
        const speaker = worldState.dialog.speakerName || '';
        drawDialogBox(ctx, canvas.width, canvas.height, line, speaker);
    }

    // === HUD ===
    drawHUD();
}

function drawHUD() {
    const map = getMap(worldState.currentMap);
    const mapName = map ? map.name : worldState.currentMap;

    // Background bar
    ctx.fillStyle = 'rgba(10, 10, 15, 0.75)';
    ctx.fillRect(0, 0, canvas.width, 32);

    ctx.font = 'bold 13px "Segoe UI", system-ui, sans-serif';
    ctx.textBaseline = 'middle';

    // Map name
    ctx.fillStyle = '#00e599';
    ctx.textAlign = 'left';
    ctx.fillText(`📍 ${mapName}`, 12, 16);

    // Inventory
    ctx.fillStyle = '#ff44aa';
    ctx.textAlign = 'right';
    ctx.fillText(`🔧 Components: ${worldState.inventory.length}`, canvas.width - 12, 16);

    // Controls hint
    ctx.fillStyle = '#555';
    ctx.textAlign = 'center';
    ctx.font = '11px "Segoe UI", system-ui, sans-serif';
    ctx.fillText('WASD: Move | E: Interact | TAB: Workshop', canvas.width / 2, 16);
}

export function startWorldLoop() {
    lastTime = performance.now();
    function loop(ts) {
        renderWorld(ts);
        animFrameId = requestAnimationFrame(loop);
    }
    animFrameId = requestAnimationFrame(loop);
}

export function stopWorldLoop() {
    if (animFrameId !== null) {
        cancelAnimationFrame(animFrameId);
        animFrameId = null;
    }
}