import * as lib from "@clusterio/lib";
import { BaseControllerPlugin } from "@clusterio/controller";
import {
	TileDataEvent,
	GetRawTileRequest,
	GetChartTagsRequest,
	ChartData,
	ChartTagDataEvent,
	ChartTagData,
} from "./messages";
import * as fs from "fs-extra";
import * as path from "path";
import * as zlib from "zlib";
import { promisify } from "util";
import sharp from "sharp";
import {
	renderChunkToPixels, 
	extractChunkFromTile, 
	renderTileToPixels,
	pixelsToRGBA
} from "./tile-utils";

const CHUNK_SIZE = 32;
const inflateAsync = promisify(zlib.inflate);

interface PixelChange {
	x: number;
	y: number;
	newColor: number;
	oldColor: number;
}

export class ControllerPlugin extends BaseControllerPlugin {
	private tilesPath: string = "";
	private chartTagsPath: string = "";
	private chunkSavingQueue = new Map<string, Map<string, { data: ChartData, tick: number }>>();
	private chartTagQueues = new Map<string, ChartTagData[]>();
	private lastSeenTagContent = new Map<string, Map<number, {
		position: [number, number];
		text: string;
		icon?: any;
		last_user?: string;
	}>>();
	private savingTiles: boolean = false;
	private savingChartTags = new Set<string>();
	private saveInterval: NodeJS.Timeout | null = null;

	async init() {
		this.tilesPath = path.resolve(
			this.controller.config.get("controller.database_directory"),
			"minimap_tiles"
		);
		this.chartTagsPath = path.resolve(
			this.controller.config.get("controller.database_directory"),
			"minimap_chart_tags"
		);
		await fs.ensureDir(this.tilesPath);
		await fs.ensureDir(this.chartTagsPath);

		this.controller.handle(TileDataEvent, this.handleTileDataEvent.bind(this));
		this.controller.handle(ChartTagDataEvent, this.handleChartTagDataEvent.bind(this));
		this.controller.handle(GetRawTileRequest, this.handleGetRawTileRequest.bind(this));
		this.controller.handle(GetChartTagsRequest, this.handleGetChartTagsRequest.bind(this));

		// Set up HTTP routes for serving tiles
		this.setupTileRoutes();

		// Load existing tag numbers for deduplication
		await this.loadExistingTagContent();

		this.saveInterval = setInterval(() => {
			this.saveTiles().catch(err => this.logger.error(`Error saving tiles: ${err}`));
			this.saveChartTags().catch(err => this.logger.error(`Error saving chart tags: ${err}`));
		}, 5000);
	}

	async onShutdown() {
		if (this.saveInterval) {
			clearInterval(this.saveInterval);
			this.saveInterval = null;
		}
		
		// Perform final save before shutdown
		await this.saveTiles();
		await this.saveChartTags();
	}

	// Compare two pixel arrays and return changes
	private comparePixels(oldPixels: Uint16Array, newPixels: Uint16Array, chunkX: number, chunkY: number): PixelChange[] {
		const changes: PixelChange[] = [];
		
		for (let y = 0; y < 32; y++) {
			for (let x = 0; x < 32; x++) {
				const index = y * 32 + x;
				const oldColor = oldPixels[index];
				const newColor = newPixels[index];
				
				if (oldColor !== newColor) {
					// Calculate absolute position within the 256x256 tile
					const absoluteX = chunkX * 32 + x;
					const absoluteY = chunkY * 32 + y;
					
					changes.push({
						x: absoluteX,
						y: absoluteY,
						newColor,
						oldColor,
					});
				}
			}
		}
		
		return changes;
	}

	// Create pixel changeset data buffer
	private createPixelChangeset(changes: PixelChange[], tick: number): Buffer {
		if (changes.length === 0) {
			return Buffer.alloc(0);
		}
		
		// Type (1) + Tick (4) + Length (2) + Pixel data (6 bytes per pixel)
		const headerSize = 7;
		const pixelDataSize = changes.length * 6; // 6 bytes per pixel change
		const totalSize = headerSize + pixelDataSize;
		const buffer = Buffer.alloc(totalSize);
		
		let offset = 0;
		
		// Type 2 for pixels
		buffer.writeUInt8(2, offset);
		offset += 1;
		
		// Tick (converted to seconds)
		buffer.writeUInt32BE(Math.floor(tick / 60), offset);
		offset += 4;
		
		// Length (number of pixel changes, not bytes)
		buffer.writeUInt16BE(changes.length, offset);
		offset += 2;
		
		// Write pixel changes
		for (const change of changes) {
			buffer.writeUInt8(change.x, offset);
			offset += 1;
			buffer.writeUInt8(change.y, offset);
			offset += 1;
			buffer.writeUInt16BE(change.newColor, offset);
			offset += 2;
			buffer.writeUInt16BE(change.oldColor, offset);
			offset += 2;
		}
		
		return buffer;
	}

	private setupTileRoutes() {
		const app = this.controller.app;

		app.get("/api/minimap/tile/:instanceId/:surface/:force/:z/:x/:y.png", async (req, res) => {
			try {
				const { instanceId, surface, force, z, x, y } = req.params;
				const tileX = parseInt(x);
				const tileY = parseInt(y);

				const tileName = `${instanceId}_${surface}_${force}_${tileX}_${tileY}.bin`;
				const tilePath = path.join(this.tilesPath, tileName);

				if (!await fs.pathExists(tilePath)) {
					res.status(404).send("Tile not found");
					return;
				}

				const tileData = await fs.readFile(tilePath);
				const image = await this.renderTile(tileData);
				res.setHeader("Content-Type", "image/png");
				res.send(image);

			} catch (err) {
				this.logger.error(`Error serving tile: ${err}`);
				res.status(500).send("Error serving tile");
			}
		});

		app.get("/api/minimap/surfaces", async (req, res) => {
			try {
				const files = await fs.readdir(this.tilesPath);
				const surfaces = new Set<string>();
				const forces = new Set<string>();

				for (const file of files) {
					if (file.endsWith(".bin")) {
						const parts = file.split("_");
						if (parts.length === 5) {
							surfaces.add(parts[1]);
							forces.add(parts[2]);
						}
					}
				}

				res.json({
					surfaces: Array.from(surfaces),
					forces: Array.from(forces),
				});
			} catch (err) {
				this.logger.error(`Error listing surfaces and forces: ${err}`);
				res.status(500).json({ error: "Failed to list surfaces and forces" });
			}
		});
	}

	async renderTile(tileData: Buffer): Promise<Buffer> {
		// Use renderTileToPixels to get the current state, then convert to image
		const currentPixels = await renderTileToPixels(tileData);
		
		// Convert RGB565 pixel data to RGBA buffer for Sharp  
		const rgbaData = pixelsToRGBA(currentPixels);
		const raw = Buffer.from(rgbaData);

		// Create and return the image directly
		return sharp(raw, { 
			raw: { width: 256, height: 256, channels: 4 } 
		}).png().toBuffer();
	}

	async saveTiles() {
		if (this.savingTiles) {
			return;
		}

		const queue = this.chunkSavingQueue;
		if (queue.size === 0) {
			return;
		}
		this.logger.info(`Starting save for ${queue.size} tiles.`);

		this.savingTiles = true;
		this.chunkSavingQueue = new Map();

		try {
			const savePromises = [];
			for (const [tileName, chunks] of queue) {
				const promise = (async () => {
					const tilePath = path.join(this.tilesPath, tileName);
					let existingTile = Buffer.alloc(0);
					if (await fs.pathExists(tilePath)) {
						existingTile = await fs.readFile(tilePath);
					}
					const newTile = await this.updateTile(existingTile, chunks);
					if (newTile && newTile.length > 0) {
						await fs.writeFile(tilePath, newTile);
					}
				})();
				savePromises.push(promise);
			}
			await Promise.all(savePromises);
		} catch (err) {
			this.logger.error(`Error saving tiles: ${err}`);
		} finally {
			this.savingTiles = false;
		}
	}

	async updateTile(existingTile: Buffer, newChunks: Map<string, { data: ChartData, tick: number }>): Promise<Buffer | undefined> {
		const existingChunks = new Map<string, { tick: number, data: Buffer }>();
		
		// Parse existing tile data to find existing chunks
		let offset = 0;
		while (offset < existingTile.length) {
			if (offset + 1 > existingTile.length) {
				this.logger.error(`Invalid tile data: cannot read type at offset ${offset}`);
				break;
			}
			
			const type = existingTile.readUInt8(offset);
			offset += 1;
			
			if (type === 1) { // Chunk
				if (offset + 7 > existingTile.length) {
					this.logger.error(`Invalid tile data: insufficient chunk header data at offset ${offset}`);
					break;
				}
				
				const tick = existingTile.readUInt32BE(offset);
				offset += 4;
				const chunkCoordsByte = existingTile.readUInt8(offset);
				offset += 1;
				const length = existingTile.readUInt16BE(offset);
				offset += 2;
				
				if (offset + length > existingTile.length) {
					this.logger.error(`Invalid tile data: insufficient chunk data at offset ${offset}`);
					break;
				}
				
				const chunkX = chunkCoordsByte >> 4;
				const chunkY = chunkCoordsByte & 0x0F;
				const chunkName = `${chunkX}_${chunkY}`;
				const data = existingTile.slice(offset, offset + length);
				offset += length;
				existingChunks.set(chunkName, { tick, data });

			} else if (type === 2) { // Pixels
				if (offset + 6 > existingTile.length) {
					this.logger.error(`Invalid tile data: insufficient pixel header data at offset ${offset}`);
					break;
				}
				
				const tick = existingTile.readUInt32BE(offset);
				offset += 4;
				const pixelCount = existingTile.readUInt16BE(offset);
				offset += 2;
				const pixelDataLength = pixelCount * 6;
				
				if (offset + pixelDataLength > existingTile.length) {
					this.logger.error(`Invalid tile data: insufficient pixel data at offset ${offset}`);
					break;
				}
				
				// Skip pixel data since we're not rebuilding the file
				offset += pixelDataLength;
			} else {
				this.logger.error(`Unknown tile data type: ${type} at offset ${offset}`);
				break;
			}
		}

		// Render the current state of the entire tile if we have existing data
		let currentTilePixels: Uint16Array | null = null;
		if (existingTile.length > 0) {
			currentTilePixels = await renderTileToPixels(existingTile);
		}

		// Process new chunks and determine what to append
		const appendBuffers: Buffer[] = [];
		let hasChanges = false;
		
		for (const [chunkName, newChunk] of newChunks) {
			const newChunkData = Buffer.from(newChunk.data.chart_data, "base64");
			const [chunkX, chunkY] = chunkName.split("_").map(Number);
			
			if (!existingChunks.has(chunkName)) {
				// New chunk - append as chunk data (type 1)
				this.logger.info(`Adding new chunk ${chunkName} to tile`);
				const header = Buffer.alloc(8);
				header.writeUInt8(1, 0); // Type 1 (chunk)
				header.writeUInt32BE(Math.floor(newChunk.tick / 60), 1); // Tick
				header.writeUInt8((chunkX << 4) | chunkY, 5); // Coords
				header.writeUInt16BE(newChunkData.length, 6); // Length
				appendBuffers.push(header, newChunkData);
				hasChanges = true;
			} else {
				// Existing chunk - compare current tile state with new chunk data
				const newPixels = await renderChunkToPixels(newChunkData);
				
				let oldPixels: Uint16Array;
				if (currentTilePixels) {
					// Extract current chunk area from the rendered tile
					oldPixels = extractChunkFromTile(currentTilePixels, chunkX, chunkY);
				} else {
					// Fallback to black pixels if tile couldn't be rendered
					oldPixels = new Uint16Array(32 * 32);
				}
				
				const changes = this.comparePixels(oldPixels, newPixels, chunkX, chunkY);
				if (changes.length > 0) {
					this.logger.info(`Adding ${changes.length} pixel changes for chunk ${chunkName} to tile`);
					const changeset = this.createPixelChangeset(changes, newChunk.tick);
					if (changeset.length > 0) {
						appendBuffers.push(changeset);
						hasChanges = true;
					}
				}
			}
		}

		if (!hasChanges) {
			return;
		}

		// Append new data to existing tile (never modify existing data)
		return Buffer.concat([existingTile, ...appendBuffers]);
	}

	async loadExistingTagContent() {
		try {
			if (!await fs.pathExists(this.chartTagsPath)) {
				return;
			}

			const files = await fs.readdir(this.chartTagsPath);
			const tagFiles = files.filter(file => file.endsWith('_chart_tags.json'));

			for (const file of tagFiles) {
				const fileKey = file.replace('_chart_tags.json', '');
				const filePath = path.join(this.chartTagsPath, file);
				
				if (!this.lastSeenTagContent.has(fileKey)) {
					this.lastSeenTagContent.set(fileKey, new Map());
				}
				const seenTags = this.lastSeenTagContent.get(fileKey)!;

				try {
					const content = await fs.readFile(filePath, 'utf-8');
					const lines = content.trim().split('\n').filter(line => line.trim());
					
					for (const line of lines) {
						try {
							const tagData = JSON.parse(line);
							if (typeof tagData.tag_number === 'number' && !tagData.end_tick) {
								// Only store the latest content for tags that haven't been deleted
								seenTags.set(tagData.tag_number, {
									position: tagData.position,
									text: tagData.text,
									icon: tagData.icon,
									last_user: tagData.last_user
								});
							}
						} catch (parseErr) {
							this.logger.warn(`Failed to parse chart tag line in ${file}: ${parseErr}`);
						}
					}
					
					this.logger.info(`Loaded ${seenTags.size} existing tag contents from ${file}`);
				} catch (readErr) {
					this.logger.warn(`Failed to read chart tag file ${file}: ${readErr}`);
				}
			}
		} catch (err) {
			this.logger.error(`Error loading existing tag content: ${err}`);
		}
	}

	async saveChartTags() {
		if (this.chartTagQueues.size === 0) {
			return;
		}

		const savePromises = [];
		for (const [fileKey, tags] of this.chartTagQueues) {
			if (tags.length === 0 || this.savingChartTags.has(fileKey)) {
				// Remove empty queues to prevent repeated processing
				if (tags.length === 0 && !this.savingChartTags.has(fileKey)) {
					this.chartTagQueues.delete(fileKey);
				}
				continue;
			}

			const promise = (async () => {
				this.savingChartTags.add(fileKey);
				const tagsToSave = [...tags];
				tags.length = 0; // Clear the queue

				try {
					const filePath = path.join(this.chartTagsPath, `${fileKey}_chart_tags.json`);
					
					// Convert chart tags to newline-delimited JSON format
					const jsonLines = tagsToSave.map(tag => JSON.stringify(tag)).join('\n');
					
					await fs.appendFile(filePath, jsonLines + '\n');
					
					// Mark tags as successfully saved
					if (!this.lastSeenTagContent.has(fileKey)) {
						this.lastSeenTagContent.set(fileKey, new Map());
					}
					const seenTags = this.lastSeenTagContent.get(fileKey)!;
					for (const tag of tagsToSave) {
						seenTags.set(tag.tag_number, {
							position: tag.position,
							text: tag.text,
							icon: tag.icon,
							last_user: tag.last_user
						});
					}
					
					this.logger.info(`Saved ${tagsToSave.length} chart tag entries to ${fileKey}`);
				} catch (err) {
					this.logger.error(`Error saving chart tags for ${fileKey}: ${err}`);
					// Re-queue the failed tags
					tags.unshift(...tagsToSave);
				} finally {
					this.savingChartTags.delete(fileKey);
				}
			})();
			savePromises.push(promise);
		}

		await Promise.all(savePromises);
	}

	async handleChartTagDataEvent(event: ChartTagDataEvent) {
		try {
			const { instance_id, tag_data } = event;

			// Create file key based on instance, surface, and force
			const fileKey = `${instance_id}_${tag_data.surface}_${tag_data.force}`;

			// Initialize seen tags map if it doesn't exist
			if (!this.lastSeenTagContent.has(fileKey)) {
				this.lastSeenTagContent.set(fileKey, new Map());
			}

			// Check for duplicate content, but allow deletion events (end_tick set) even if we've seen the tag before
			const seenTags = this.lastSeenTagContent.get(fileKey)!;
			const lastSeenContent = seenTags.get(tag_data.tag_number);
			
			// For deletion events (end_tick set), always allow through
			if (tag_data.end_tick !== undefined) {
				// Don't skip deletion events
			} else if (lastSeenContent) {
				// For creation/modification events, check if content has actually changed
				const contentUnchanged = 
					lastSeenContent.position[0] === tag_data.position[0] &&
					lastSeenContent.position[1] === tag_data.position[1] &&
					lastSeenContent.text === tag_data.text &&
					JSON.stringify(lastSeenContent.icon) === JSON.stringify(tag_data.icon) &&
					lastSeenContent.last_user === tag_data.last_user;
				
				if (contentUnchanged) {
					return; // Skip if content hasn't changed
				}
			}

			// Add instance_id to the tag data for storage
			const enrichedTagData = {
				...tag_data,
				instance_id
			};

			// Initialize queue if it doesn't exist
			if (!this.chartTagQueues.has(fileKey)) {
				this.chartTagQueues.set(fileKey, []);
			}

			// Queue for batch saving
			this.chartTagQueues.get(fileKey)!.push(enrichedTagData);

			// Send live update to connected web clients
			const updateEvent = new ChartTagDataEvent(instance_id, tag_data);
			
			// Broadcast to web clients (overriding the formal src/dst routing)
			this.controller.sendTo(new lib.Address(lib.Address.broadcast, lib.Address.control), updateEvent);

		} catch (err) {
			this.logger.error(`Error processing chart tag data: ${err}`);
		}
	}

	async handleTileDataEvent(event: TileDataEvent) {
		try {
			const { instance_id, surface, force, x, y, tick, chunk } = event;

			// Calculate tile coordinates for 8x8 chunks per tile (256x256 pixels)
			const tileX = Math.floor(x / 32 / 8);
			const tileY = Math.floor(y / 32 / 8);
			const tileName = `${instance_id}_${surface}_${force}_${tileX}_${tileY}.bin`;

			// Fix negative modulo results by using proper modulo operation (0-7 range for 8x8)
			const chunkX = ((Math.floor(x / 32) % 8) + 8) % 8;
			const chunkY = ((Math.floor(y / 32) % 8) + 8) % 8;
			const chunkName = `${chunkX}_${chunkY}`;

			if (!this.chunkSavingQueue.has(tileName)) {
				this.chunkSavingQueue.set(tileName, new Map());
			}
			this.chunkSavingQueue.get(tileName)!.set(chunkName, { data: chunk, tick });

			// Send live update to connected web clients
			const updateEvent = new TileDataEvent(
				instance_id,
				surface,
				force,
				x,
				y,
				tick,
				chunk
			);
			
			// Broadcast to web clients (overriding the formal src/dst routing)
			this.controller.sendTo(new lib.Address(lib.Address.broadcast, lib.Address.control), updateEvent);

		} catch (err) {
			this.logger.error(`Error processing tile data: ${err}`);
		}
	}

	async handleGetRawTileRequest(request: GetRawTileRequest) {
		const { instance_id, surface, force, tile_x, tile_y, tick } = request;
		
		const tileName = `${instance_id}_${surface}_${force}_${tile_x}_${tile_y}.bin`;
		const tilePath = path.join(this.tilesPath, tileName);

		if (!await fs.pathExists(tilePath)) {
			return { tile_data: null, tick: tick || 0 };
		}

		try {
			const tileData = await fs.readFile(tilePath);
			
			const base64Data = tileData.toString('base64');
			
			return { 
				tile_data: base64Data
			};
		} catch (err) {
			this.logger.error(`Error reading tile file: ${err}`);
			return { tile_data: null };
		}
	}

	async handleGetChartTagsRequest(request: GetChartTagsRequest) {
		const { instance_id, surface, force } = request;
		
		const fileKey = `${instance_id}_${surface}_${force}`;
		const filePath = path.join(this.chartTagsPath, `${fileKey}_chart_tags.json`);

		if (!await fs.pathExists(filePath)) {
			return { chart_tags: [] };
		}

		try {
			const content = await fs.readFile(filePath, 'utf-8');
			const lines = content.trim().split('\n').filter(line => line.trim());
			
			const chartTags: ChartTagData[] = [];
			for (const line of lines) {
				try {
					const tagData = JSON.parse(line);
					chartTags.push(tagData);
				} catch (parseErr) {
					this.logger.warn(`Failed to parse chart tag line: ${parseErr}`);
				}
			}
			
			return { chart_tags: chartTags };
		} catch (err) {
			this.logger.error(`Error reading chart tag file: ${err}`);
			return { chart_tags: [] };
		}
	}
}