import * as fs from "node:fs";
import * as path from "node:path";
import { glob } from "glob";
import type { CireConfig, FileIR } from "../types";
import { NavigationGenerator } from "../utils/navigation-generator";
import { WorkflowManager } from "./WorkflowManager";

export interface BuildStats {
	totalFiles: number;
	processedFiles: number;
	failedFiles: number;
	processingTime: number;
}

export class ProjectBuilder {
	private workflowManager: WorkflowManager | null = null;
	private cireConfig: CireConfig;

	constructor(config: CireConfig) {
		this.cireConfig = config;
	}

	

	async buildProject(): Promise<BuildStats> {
		const startTime = Date.now();

		try {
			// 1. Load configuration
			const config = this.cireConfig;

			if (config.logLevel === "info") {
				console.log(`📁 Loaded config for: ${config.name}`);
				console.log(`📂 Input root: ${config.input.root}`);
				console.log(`📤 Output directory: ${config.output.directory}`);
			}

			// 2. Scan source code files
			const sourceFiles = await this.scanSourceFiles(config);

			if (config.logLevel === "info") {
				console.log(`🔍 Found ${sourceFiles.length} source files`);
			}

			// 3. Create output directory
			const outputDir = config.output.directory;
			await this.ensureOutputDirectory(outputDir);

			// 4. Initialize WorkflowManager
			this.workflowManager = this.createWorkflowManager(config);

			// 5. Batch process files
			const stats = await this.processFiles(
				sourceFiles,
				outputDir,
				config,
			);

			// 6. Copy asset files
			await this.copyAssets(outputDir);

			// 7. Generate navigation index page (only for HTML output)
			if (config.outputFormat?.backend !== "markdown") {
				await this.generateNavigationIndex(
					sourceFiles,
					outputDir,
					config,
				);
			}

			const processingTime = Date.now() - startTime;

			return {
				...stats,
				processingTime,
			};
		} catch (error) {
			throw new Error(`Project build failed: ${error}`);
		}
	}

	

	private async scanSourceFiles(config: CireConfig): Promise<string[]> {
		const { root, include, exclude } = config.input;
		const sourceFiles: string[] = [];

		// Resolve absolute path
		const absoluteRoot = path.resolve(root);

		// Find files for each include pattern
		for (const pattern of include) {
			const fullPattern = path.join(absoluteRoot, pattern);

			if (this.cireConfig.description) {
				console.log(`🔍 Scanning pattern: ${fullPattern}`);
			}

			const files = await glob(fullPattern, {
				ignore: exclude?.map((exclude) =>
					path.join(absoluteRoot, exclude),
				),
				absolute: true,
			});

			sourceFiles.push(...files);
		}

		// Remove duplicates and sort
		return [...new Set(sourceFiles)].sort();
	}

	

	private async ensureOutputDirectory(outputDir: string): Promise<void> {
		const absoluteOutputDir = path.resolve(outputDir);

		if (!fs.existsSync(absoluteOutputDir)) {
			fs.mkdirSync(absoluteOutputDir, { recursive: true });
			console.log(`📁 Created output directory: ${absoluteOutputDir}`);
		}
	}

	

	private createWorkflowManager(config: CireConfig): WorkflowManager {
		return new WorkflowManager(config);
	}

	

	private async processFiles(
		sourceFiles: string[],
		outputDir: string,
		config: CireConfig,
		verbose: boolean = false,
	): Promise<{
		processedFiles: number;
		failedFiles: number;
		totalFiles: number;
	}> {
		let processedFiles = 0;
		let failedFiles = 0;

		console.log(`🚀 Processing ${sourceFiles.length} files...`);

		for (const sourceFile of sourceFiles) {
			try {
				await this.processSingleFile(sourceFile, outputDir, config);
				processedFiles++;

				if (verbose) {
					console.log(
						`✅ Processed: ${path.relative(process.cwd(), sourceFile)}`,
					);
				} else if (
					processedFiles % 10 === 0 ||
					processedFiles === sourceFiles.length
				) {
					// Show progress every 10 files or when complete
					const progress = Math.round(
						(processedFiles / sourceFiles.length) * 100,
					);
					process.stdout.write(
						`\r⏳ Progress: ${progress}% (${processedFiles}/${sourceFiles.length})`,
					);
				}
			} catch (error) {
				failedFiles++;
				console.error(`\n❌ Failed to process ${sourceFile}:`, error);
			}
		}

		// Clear progress line
		if (!verbose) {
			process.stdout.write(`\r${" ".repeat(50)}\r`);
		}

		console.log(
			`\n✨ Processing complete: ${processedFiles} success, ${failedFiles} failed`,
		);

		return {
			processedFiles,
			failedFiles,
			totalFiles: sourceFiles.length,
		};
	}

	

	private async processSingleFile(
		sourceFile: string,
		outputDir: string,
		config: CireConfig,
	): Promise<void> {
		if (!this.workflowManager) {
			throw new Error("WorkflowManager not initialized");
		}

		// Calculate relative path and create FileIR
		const projectRoot = config.input.root;
		const relativePath = path.relative(projectRoot, sourceFile);
		const fileIR: FileIR = {
			relativePath,
			language: config.input.language,
		};

		// Process file through WorkflowManager
		const output = this.workflowManager.processFile(fileIR, projectRoot);
		const outputPath = path.resolve(outputDir, relativePath);

		// Determine output file extension based on config
		const backend = this.cireConfig.outputFormat?.backend || "html";
		const outputExtension = backend === "markdown" ? ".md" : ".html";
		const outputFilePath = outputPath.replace(/\.[^.]+$/, outputExtension);

		// Ensure output file directory exists
		const outputDirPath = path.dirname(outputFilePath);
		if (!fs.existsSync(outputDirPath)) {
			fs.mkdirSync(outputDirPath, { recursive: true });
		}

		// Write output file
		fs.writeFileSync(outputFilePath, output, "utf-8");
	}

	

	private async copyAssets(
		outputDir: string,
		verbose: boolean = false,
	): Promise<void> {
		const templateDir = path.resolve(__dirname, "../../templates");
		const cssSourcePath = path.join(templateDir, "default.css");
		const cssTargetPath = path.resolve(outputDir, "default.css");

		if (fs.existsSync(cssSourcePath)) {
			fs.copyFileSync(cssSourcePath, cssTargetPath);

			if (verbose) {
				console.log(`📋 Copied CSS to: ${cssTargetPath}`);
			}
		} else {
			console.warn(`!  CSS file not found: ${cssSourcePath}`);
		}
	}

	

	private async generateNavigationIndex(
		sourceFiles: string[],
		outputDir: string,
		config: CireConfig,
	): Promise<void> {
		try {
			console.log("📋 Generating navigation index page...");

			// Convert absolute paths to relative paths for navigation display
			const relativeFiles = sourceFiles.map((file) =>
				path.relative(config.input.root, file),
			);

			const navigationGenerator = new NavigationGenerator(config);
			const navigationHTML = navigationGenerator.generateNavigationPage(
				relativeFiles,
				config,
			);

			// Determine index file name based on output format
			const backend = config.outputFormat?.backend || "html";
			const indexFileName =
				backend === "markdown" ? "cireIndex.md" : "cireIndex.html";

			await navigationGenerator.saveNavigationPage(
				navigationHTML,
				outputDir,
				indexFileName,
			);

			console.log("✅ Navigation index page generated successfully");
		} catch (error) {
			console.warn("⚠️  Failed to generate navigation index:", error);
		}
	}
}