const sharp = require('sharp');
const fs = require('fs').promises;
const path = require('path');
const { db } = require('./database');

class MapProcessor {
    constructor() {
        this.mapDir = path.join(__dirname, 'uploads', 'map');
        this.outputDir = path.join(__dirname, 'uploads', 'processed');
        this.worldMapPath = path.join(this.outputDir, 'world-map.png');
        this.tileSize = 1024; // Xaero's World Map tiles are 1024x1024
    }

    async init() {
        try {
            await fs.mkdir(this.outputDir, { recursive: true });
            console.log('Map processor initialized');
        } catch (error) {
            console.error('Error initializing map processor:', error);
        }
    }

    async getMapTiles() {
        try {
            const files = await fs.readdir(this.mapDir);
            const tileFiles = files.filter(file => file.endsWith('.png'));
            
            // Parse tile coordinates from filenames like "0_3_x-3584_z1536.png"
            const tiles = tileFiles.map(file => {
                const match = file.match(/(\d+)_(\d+)_x(-?\d+)_z(-?\d+)\.png/);
                if (match) {
                    return {
                        filename: file,
                        gridX: parseInt(match[1]),
                        gridZ: parseInt(match[2]),
                        x: parseInt(match[3]),
                        z: parseInt(match[4])
                    };
                }
                return null;
            }).filter(tile => tile !== null);

            return tiles.sort((a, b) => {
                // Sort by grid coordinates
                if (a.gridX !== b.gridX) return a.gridX - b.gridX;
                return a.gridZ - b.gridZ;
            });
        } catch (error) {
            console.error('Error reading map tiles:', error);
            return [];
        }
    }

    async calculateMapDimensions(tiles) {
        if (tiles.length === 0) return { width: 0, height: 0, offsetX: 0, offsetZ: 0 };

        // Find the center tile (3_1_x-512_z-512.png)
        //const centerTile = tiles.find(t => t.filename === '3_1_x-512_z-512.png');
        
        let centerX, centerZ;
        
        //if (centerTile) {
            // Use the specified tile as center point
        //    centerX = centerTile.x + (this.tileSize / 2); // Center of the tile
         //   centerZ = centerTile.z + (this.tileSize / 2); // Center of the tile
        //    console.log(`Using tile ${centerTile.filename} as center point at (${centerX}, ${centerZ})`);
        //} else {
            // Fallback to original logic if center tile not found
            centerX = 0;
            centerZ = 0;
            console.log('Center tile 3_1_x-512_z-512.png not found, using origin (0,0) as center');
        //}

        // Calculate bounds relative to the center
        const minX = Math.min(...tiles.map(t => t.x));
        const maxX = Math.max(...tiles.map(t => t.x + this.tileSize));
        const minZ = Math.min(...tiles.map(t => t.z));
        const maxZ = Math.max(...tiles.map(t => t.z + this.tileSize));

        const width = maxX - minX;
        const height = maxZ - minZ;
        
        // Calculate offsets to make the center tile the origin (0,0)
        // We need to shift everything so that the center point becomes (0,0)
        const offsetX = -centerX;
        const offsetZ = -centerZ;

        return { width, height, offsetX, offsetZ };
    }

    async assembleWorldMap() {
        console.log('Starting world map assembly...');
        
        const tiles = await this.getMapTiles();
        if (tiles.length === 0) {
            console.log('No map tiles found');
            return false;
        }

        console.log(`Found ${tiles.length} map tiles`);

        const { width, height, offsetX, offsetZ } = await this.calculateMapDimensions(tiles);
        
        console.log(`Map dimensions: ${width}x${height}px`);
        console.log(`Offset: X=${offsetX}, Z=${offsetZ}`);

        // Create a blank canvas for the world map
        const worldMap = sharp({
            create: {
                width: width,
                height: height,
                channels: 4,
                background: { r: 0, g: 0, b: 0, alpha: 0 }
            }
        });

        // Composite each tile onto the world map
        const overlays = await Promise.all(tiles.map(async (tile) => {
            const tilePath = path.join(this.mapDir, tile.filename);
            const x = tile.x + offsetX;
            const y = tile.z + offsetZ;

            return {
                input: tilePath,
                left: x,
                top: y
            };
        }));

        try {
            await worldMap
                .composite(overlays)
                .png()
                .toFile(this.worldMapPath);

            // Update map metadata in database
            await this.updateMapMetadata({
                width: width,
                height: height,
                offsetX: offsetX,
                offsetZ: offsetZ,
                tileSize: this.tileSize,
                lastUpdated: new Date().toISOString()
            });

            console.log(`World map assembled: ${this.worldMapPath}`);
            return true;
        } catch (error) {
            console.error('Error assembling world map:', error);
            return false;
        }
    }

    async updateMapMetadata(metadata) {
        return new Promise((resolve, reject) => {
            const keys = Object.keys(metadata);
            const values = Object.values(metadata);
            
            const updatePromises = keys.map((key, index) => {
                return new Promise((resolve, reject) => {
                    db.run(
                        `INSERT INTO map_metadata (\`key\`, value) VALUES (?, ?) 
                         ON DUPLICATE KEY UPDATE value = VALUES(value)`,
                        [key, values[index]],
                        (err) => {
                            if (err) reject(err);
                            else resolve();
                        }
                    );
                });
            });

            Promise.all(updatePromises)
                .then(() => resolve())
                .catch(reject);
        });
    }

    async getMapMetadata() {
        return new Promise((resolve, reject) => {
            db.all('SELECT `key`, value FROM map_metadata', [], (err, rows) => {
                if (err) reject(err);
                else {
                    const metadata = {};
                    rows.forEach(row => {
                        metadata[row.key] = row.value;
                    });
                    resolve(metadata);
                }
            });
        });
    }

    async getWorldMapUrl() {
        const metadata = await this.getMapMetadata();
        if (metadata.width && metadata.height) {
            return '/api/map/world-map';
        }
        return null;
    }

    async getCoordinateConversion(x, z) {
        const metadata = await this.getMapMetadata();
        if (!metadata.width || !metadata.height) {
            return { x: 0, y: 0 };
        }

        const offsetX = parseInt(metadata.offsetX) || 0;
        const offsetZ = parseInt(metadata.offsetZ) || 0;
        const width = parseInt(metadata.width);
        const height = parseInt(metadata.height);

        // Convert Minecraft coordinates to pixel coordinates
        const pixelX = x + offsetX;
        const pixelY = z + offsetZ;

        // Convert to percentage for frontend (0-100%)
        const percentX = (pixelX / width) * 100;
        const percentY = (pixelY / height) * 100;

        return {
            x: percentX,
            y: percentY,
            pixelX: pixelX,
            pixelY: pixelY
        };
    }

    async getMarkersWithCoordinates() {
        return new Promise((resolve, reject) => {
            db.all('SELECT * FROM map_markers WHERE is_public = 1', [], async (err, markers) => {
                if (err) reject(err);
                else {
                    const markersWithCoords = await Promise.all(markers.map(async (marker) => {
                        const coords = await this.getCoordinateConversion(marker.x_coord, marker.z_coord);
                        return {
                            ...marker,
                            coordinates: coords
                        };
                    }));
                    resolve(markersWithCoords);
                }
            });
        });
    }
}

module.exports = MapProcessor;