FileSource.ts

/**
 * FileSource - Main implementation for FileSource feature
 *
 * This source integrates files as tasks into the dataflow architecture.
 * It follows the same patterns as ObsidianSource and IcsSource.
 */

import type { App, TFile, EventRef, CachedMetadata } from "obsidian";
import type TaskProgressBarPlugin from "@/index";
import type { Task } from "@/types/task";
import type {
	FileSourceConfiguration,
	FileSourceTaskMetadata,
	FileSourceStats,
	FileTaskCache,
	RecognitionStrategy,
	PathRecognitionConfig,
	TemplateRecognitionConfig,
	MetadataMappingConfig,
} from "@/types/file-source";

import { Events, emit, Seq, on } from "../events/Events";
import { FileSourceConfig } from "./FileSourceConfig";

import { FileFilterManager } from "@/managers/file-filter-manager";

/**
 * FileSource - Independent event source for file-based tasks
 *
 * Subscribes to file events and transforms qualifying files into tasks
 * following the established dataflow patterns.
 */
export class FileSource {
	/**
	 * Default status mappings from textual values to task symbols
	 * Provides fallback mappings when user configuration doesn't specify a mapping
	 */
	private static readonly DEFAULT_STATUS_MAPPINGS: Record<string, string> = {
		completed: "x",
		done: "x",
		finished: "x",
		"in-progress": "/",
		"in progress": "/",
		doing: "/",
		planned: "?",
		todo: "?",
		cancelled: "-",
		canceled: "-",
		"not-started": " ",
		"not started": " ",
	};

	private config: FileSourceConfig;
	private isInitialized = false;
	private lastUpdateSeq = 0;

	// Event references for cleanup
	private eventRefs: EventRef[] = [];

	// Cache for tracking file task state
	private fileTaskCache = new Map<string, FileTaskCache>();

	// Debouncing for rapid changes
	private pendingUpdates = new Map<string, NodeJS.Timeout>();
	private readonly DEBOUNCE_DELAY = 300; // ms

	// Statistics tracking
	private stats: FileSourceStats = {
		initialized: false,
		trackedFileCount: 0,
		recognitionBreakdown: {
			metadata: 0,
			tag: 0,
			template: 0,
			path: 0,
		},
		lastUpdate: 0,
		lastUpdateSeq: 0,
	};

	constructor(
		private app: App,
		initialConfig?: Partial<FileSourceConfiguration>,
		private fileFilterManager?: FileFilterManager,
		private plugin?: TaskProgressBarPlugin
	) {
		this.config = new FileSourceConfig(initialConfig);
	}

	/**
	 * Initialize FileSource and start listening for events
	 */
	async initialize(): Promise<void> {
		if (this.isInitialized) return;
		if (!this.config.isEnabled()) return;

		console.log("[FileSource] Initializing FileSource...");

		// Subscribe to configuration changes
		this.config.onChange((newConfig) => {
			this.handleConfigChange(newConfig);
		});

		// Subscribe to file events
		this.subscribeToFileEvents();

		this.isInitialized = true;
		this.stats.initialized = true;

		try {
			await this.performInitialScan();
		} catch (error) {
			console.error("[FileSource] Initial scan failed", error);
		}

		console.log(
			`[FileSource] Initialized with strategies: ${this.config
				.getEnabledStrategies()
				.join(", ")}`
		);
	}

	/**
	 * Subscribe to relevant file events
	 */
	private subscribeToFileEvents(): void {
		// Subscribe to FILE_UPDATED events from ObsidianSource
		this.eventRefs.push(
			on(this.app, Events.FILE_UPDATED, (payload) => {
				if (payload?.path) {
					this.handleFileUpdate(payload.path, payload.reason);
				}
			})
		);

		// Subscribe to more granular events if they exist
		// These would be added to Events.ts later in Phase 2
		this.eventRefs.push(
			on(
				this.app,
				"task-genius:file-metadata-changed" as any,
				(payload) => {
					if (payload?.path) {
						this.handleFileMetadataChange(payload.path);
					}
				}
			)
		);

		this.eventRefs.push(
			on(
				this.app,
				"task-genius:file-content-changed" as any,
				(payload) => {
					if (payload?.path) {
						this.handleFileContentChange(payload.path);
					}
				}
			)
		);
	}

	/**
	 * Handle file update events with debouncing
	 */
	private handleFileUpdate(filePath: string, reason: string): void {
		if (!this.isInitialized || !this.config.isEnabled()) return;
		const relevant = this.isRelevantFile(filePath);

		if (!relevant) return;

		// Clear existing timeout for this file
		const existingTimeout = this.pendingUpdates.get(filePath);
		if (existingTimeout) {
			clearTimeout(existingTimeout);
		}

		// Set new debounced timeout
		const timeout = setTimeout(async () => {
			this.pendingUpdates.delete(filePath);

			try {
				await this.processFileUpdate(filePath, reason);
			} catch (error) {
				console.error(
					`[FileSource] Error processing file update for ${filePath}:`,
					error
				);
			}
		}, this.DEBOUNCE_DELAY);

		this.pendingUpdates.set(filePath, timeout);
	}

	/**
	 * Handle granular metadata changes (Phase 2 enhancement)
	 */
	private handleFileMetadataChange(filePath: string): void {
		if (!this.shouldUpdateFileTask(filePath, "metadata")) return;
		this.handleFileUpdate(filePath, "frontmatter");
	}

	/**
	 * Handle granular content changes (Phase 2 enhancement)
	 */
	private handleFileContentChange(filePath: string): void {
		if (!this.shouldUpdateFileTask(filePath, "content")) return;
		this.handleFileUpdate(filePath, "modify");
	}

	/**
	 * Process a file update and determine if it should be a file task
	 */
	private async processFileUpdate(
		filePath: string,
		reason: string
	): Promise<void> {
		if (reason === "delete") {
			await this.removeFileTask(filePath);
			return;
		}

		const shouldBeTask = await this.shouldCreateFileTask(filePath);
		const existingCache = this.fileTaskCache.get(filePath);
		const wasTask = existingCache?.fileTaskExists ?? false;

		if (shouldBeTask && !wasTask) {
			// File should become a task
			await this.createFileTask(filePath);
		} else if (shouldBeTask && wasTask) {
			// File is already a task, check if it needs updating
			await this.updateFileTask(filePath);
		} else if (!shouldBeTask && wasTask) {
			// File should no longer be a task
			await this.removeFileTask(filePath);
		}
		// else: File is not and should not be a task, do nothing
	}

	/**
	 * Check if a file should be treated as a task
	 */
	async shouldCreateFileTask(filePath: string): Promise<boolean> {
		// Fast reject non-relevant files before any IO
		if (!this.isRelevantFile(filePath)) return false;

		const file = this.app.vault.getAbstractFileByPath(filePath) as TFile;
		if (!file) return false;

		try {
			const fileContent = await this.app.vault.cachedRead(file);
			const fileCache = this.app.metadataCache.getFileCache(file);

			return this.evaluateRecognitionStrategies(
				filePath,
				fileContent,
				fileCache
			);
		} catch (error) {
			console.error(
				`[FileSource] Error reading file ${filePath}:`,
				error
			);
			return false;
		}
	}

	/**
	 * Evaluate all enabled recognition strategies
	 */
	private evaluateRecognitionStrategies(
		filePath: string,
		fileContent: string,
		fileCache: CachedMetadata | null
	): boolean {
		const config = this.config.getConfig();
		const { recognitionStrategies } = config;

		// Check metadata strategy
		if (recognitionStrategies.metadata.enabled) {
			if (
				this.matchesMetadataStrategy(
					filePath,
					fileContent,
					fileCache,
					recognitionStrategies.metadata
				)
			) {
				return true;
			}
		}

		// Check tag strategy
		if (recognitionStrategies.tags.enabled) {
			if (
				this.matchesTagStrategy(
					filePath,
					fileContent,
					fileCache,
					recognitionStrategies.tags
				)
			) {
				return true;
			}
		}

		// Check template strategy (Phase 2)
		if (recognitionStrategies.templates.enabled) {
			if (
				this.matchesTemplateStrategy(
					filePath,
					fileContent,
					fileCache,
					recognitionStrategies.templates
				)
			) {
				return true;
			}
		}

		// Check path strategy (Phase 2)
		if (recognitionStrategies.paths.enabled) {
			if (
				this.matchesPathStrategy(
					filePath,
					fileContent,
					fileCache,
					recognitionStrategies.paths
				)
			) {
				return true;
			}
		}

		return false;
	}

	/**
	 * Check if file matches metadata strategy
	 */
	private matchesMetadataStrategy(
		filePath: string,
		fileContent: string,
		fileCache: CachedMetadata | null,
		config: any
	): boolean {
		if (!fileCache?.frontmatter) return false;

		const { taskFields, requireAllFields } = config;
		const frontmatter = fileCache.frontmatter;

		const matchingFields = taskFields.filter(
			(field: string) =>
				frontmatter.hasOwnProperty(field) &&
				frontmatter[field] !== undefined
		);

		if (requireAllFields) {
			return matchingFields.length === taskFields.length;
		} else {
			return matchingFields.length > 0;
		}
	}

	/**
	 * Check if file matches tag strategy
	 */
	private matchesTagStrategy(
		filePath: string,
		fileContent: string,
		fileCache: CachedMetadata | null,
		config: any
	): boolean {
		if (!fileCache?.tags) return false;

		const { taskTags, matchMode } = config;
		const fileTags = fileCache.tags.map((tag) => tag.tag);

		return taskTags.some((taskTag: string) => {
			return fileTags.some((fileTag) => {
				switch (matchMode) {
					case "exact":
						return fileTag === taskTag;
					case "prefix":
						return fileTag.startsWith(taskTag);
					case "contains":
						return fileTag.includes(taskTag);
					default:
						return fileTag === taskTag;
				}
			});
		});
	}

	/**
	 * Check if file matches template strategy
	 */
	private matchesTemplateStrategy(
		filePath: string,
		fileContent: string,
		fileCache: CachedMetadata | null,
		config: TemplateRecognitionConfig
	): boolean {
		if (
			!config.enabled ||
			!config.templatePaths ||
			config.templatePaths.length === 0
		) {
			return false;
		}

		// Check if file matches any template path
		return config.templatePaths.some((templatePath) => {
			// Check direct path inclusion
			if (filePath.includes(templatePath)) {
				return true;
			}

			// Check frontmatter template references
			if (config.checkTemplateMetadata && fileCache?.frontmatter) {
				const frontmatter = fileCache.frontmatter;
				return (
					frontmatter.template === templatePath ||
					frontmatter.templateFile === templatePath ||
					frontmatter.templatePath === templatePath
				);
			}

			return false;
		});
	}

	/**
	 * Check if file matches path strategy
	 */
	private matchesPathStrategy(
		filePath: string,
		fileContent: string,
		fileCache: CachedMetadata | null,
		config: PathRecognitionConfig
	): boolean {
		if (
			!config.enabled ||
			!config.taskPaths ||
			config.taskPaths.length === 0
		) {
			return false;
		}

		// Normalize path (use forward slashes)
		const normalizedPath = filePath.replace(/\\/g, "/");

		// Check each configured path pattern
		for (const pattern of config.taskPaths) {
			const normalizedPattern = pattern.replace(/\\/g, "/");

			switch (config.matchMode) {
				case "prefix":
					if (normalizedPath.startsWith(normalizedPattern)) {
						console.log(
							`[FileSource] Path matches prefix pattern: ${pattern} for ${filePath}`
						);
						return true;
					}
					break;

				case "regex":
					try {
						const regex = new RegExp(normalizedPattern);
						if (regex.test(normalizedPath)) {
							console.log(
								`[FileSource] Path matches regex pattern: ${pattern} for ${filePath}`
							);
							return true;
						}
					} catch (e) {
						console.warn(
							`[FileSource] Invalid regex pattern: ${pattern}`,
							e
						);
					}
					break;

				case "glob":
					if (
						this.matchGlobPattern(normalizedPath, normalizedPattern)
					) {
						console.log(
							`[FileSource] Path matches glob pattern: ${pattern} for ${filePath}`
						);
						return true;
					}
					break;
			}
		}

		return false;
	}

	/**
	 * Match a path against a glob pattern
	 * Supports: * (any chars except /), ** (any chars), ? (single char)
	 */
	private matchGlobPattern(path: string, pattern: string): boolean {
		// Convert glob pattern to regular expression
		let regexPattern = pattern
			.replace(/[.+^${}()|[\]\\]/g, "\\$&") // Escape special chars
			.replace(/\*\*/g, "§§§") // Temporary placeholder for **
			.replace(/\*/g, "[^/]*") // * matches any chars except /
			.replace(/§§§/g, ".*") // ** matches any chars
			.replace(/\?/g, "[^/]"); // ? matches single char

		// If pattern ends with /, match all files in that directory
		if (pattern.endsWith("/")) {
			regexPattern = `^${regexPattern}.*`;
		} else {
			regexPattern = `^${regexPattern}$`;
		}

		try {
			const regex = new RegExp(regexPattern);
			return regex.test(path);
		} catch (e) {
			console.warn(
				`[FileSource] Failed to compile glob pattern: ${pattern}`,
				e
			);
			return false;
		}
	}

	/**
	 * Create a new file task
	 */
	async createFileTask(
		filePath: string
	): Promise<Task<FileSourceTaskMetadata> | null> {
		const file = this.app.vault.getAbstractFileByPath(filePath) as TFile;
		if (!file) return null;

		try {
			const fileContent = await this.app.vault.cachedRead(file);
			const fileCache = this.app.metadataCache.getFileCache(file);

			const fileTask = await this.buildFileTask(
				filePath,
				fileContent,
				fileCache
			);
			if (!fileTask) return null;

			// Update cache
			this.updateFileTaskCache(filePath, fileTask);

			// Update statistics
			this.updateStatistics(fileTask.metadata.recognitionStrategy, 1);

			// Emit file task event
			this.emitFileTaskUpdate("created", fileTask);

			return fileTask;
		} catch (error) {
			console.error(
				`[FileSource] Error creating file task for ${filePath}:`,
				error
			);
			return null;
		}
	}

	/**
	 * Update an existing file task
	 */
	async updateFileTask(
		filePath: string
	): Promise<Task<FileSourceTaskMetadata> | null> {
		// For Phase 1, just recreate the task
		// Phase 2 will add smart update detection
		return await this.createFileTask(filePath);
	}

	/**
	 * Remove a file task
	 */
	async removeFileTask(filePath: string): Promise<void> {
		const existingCache = this.fileTaskCache.get(filePath);
		if (!existingCache?.fileTaskExists) return;

		// Remove from cache
		this.fileTaskCache.delete(filePath);

		// Update statistics
		this.stats.trackedFileCount = Math.max(
			0,
			this.stats.trackedFileCount - 1
		);

		// Emit removal event
		const seq = Seq.next();
		this.lastUpdateSeq = seq;

		emit(this.app, Events.FILE_TASK_REMOVED, {
			filePath,
			timestamp: Date.now(),
			seq,
		});

		console.log(`[FileSource] Removed file task: ${filePath}`);
	}

	/**
	 * Build a file task from file data
	 */
	private async buildFileTask(
		filePath: string,
		fileContent: string,
		fileCache: CachedMetadata | null
	): Promise<Task<FileSourceTaskMetadata> | null> {
		const config = this.config.getConfig();
		const file = this.app.vault.getAbstractFileByPath(filePath) as TFile;
		if (!file) return null;

		// Determine which strategy matched
		const strategy = this.getMatchingStrategy(
			filePath,
			fileContent,
			fileCache
		);
		if (!strategy) return null;

		// Generate task content based on configuration
		const content = this.generateTaskContent(
			filePath,
			fileContent,
			fileCache
		);
		const safeContent =
			typeof content === "string"
				? content
				: filePath.split("/").pop() || filePath;

		// Extract metadata from frontmatter
		const metadataResult = this.extractTaskMetadata(
			filePath,
			fileContent,
			fileCache,
			strategy
		);

		// Separate rawStatus from metadata (rawStatus is not part of FileSourceTaskMetadata)
		const { rawStatus, ...metadata } = metadataResult;

		// Compute status symbol from raw frontmatter value (BaseTask layer)
		const status = this.computeStatusSymbol(
			rawStatus,
			config.fileTaskProperties.defaultStatus
		);

		// Log status mapping if conversion occurred
		if (rawStatus && status !== rawStatus) {
			console.log(
				`[FileSource] Mapped status '${rawStatus}' to '${status}' for ${filePath}`
			);
		}

		// Create the file task
		const fileTask: Task<FileSourceTaskMetadata> = {
			id: `file-source:${filePath}`,
			content: safeContent,
			filePath,
			line: 0, // File tasks are at line 0
			completed: status === "x" || status === "X",
			status: status,
			originalMarkdown: `**${safeContent}**`,
			metadata: {
				...metadata,
				source: "file-source",
				recognitionStrategy: strategy.name,
				recognitionCriteria: strategy.criteria,
				fileTimestamps: {
					created: file.stat.ctime,
					modified: file.stat.mtime,
				},
				childTasks: [], // Will be populated in Phase 3
				tags: metadata.tags || [],
				children: [], // Required by StandardTaskMetadata
			},
		};

		return fileTask;
	}

	/**
	 * Get the matching recognition strategy for a file
	 */
	private getMatchingStrategy(
		filePath: string,
		fileContent: string,
		fileCache: CachedMetadata | null
	): { name: RecognitionStrategy; criteria: string } | null {
		const config = this.config.getConfig();

		if (
			config.recognitionStrategies.metadata.enabled &&
			this.matchesMetadataStrategy(
				filePath,
				fileContent,
				fileCache,
				config.recognitionStrategies.metadata
			)
		) {
			return { name: "metadata", criteria: "frontmatter" };
		}

		if (
			config.recognitionStrategies.tags.enabled &&
			this.matchesTagStrategy(
				filePath,
				fileContent,
				fileCache,
				config.recognitionStrategies.tags
			)
		) {
			return { name: "tag", criteria: "file-tags" };
		}

		// Check path strategy
		if (
			config.recognitionStrategies.paths.enabled &&
			this.matchesPathStrategy(
				filePath,
				fileContent,
				fileCache,
				config.recognitionStrategies.paths
			)
		) {
			return {
				name: "path",
				criteria:
					config.recognitionStrategies.paths.taskPaths.join(", "),
			};
		}

		// Template-based recognition
		const templateConfig = config.recognitionStrategies.templates;
		if (templateConfig.enabled && templateConfig.templatePaths.length > 0) {
			// Check if file matches any template path
			const matchesTemplate = templateConfig.templatePaths.some(
				(templatePath) => {
					// Simple path matching - could be enhanced with more sophisticated matching
					return (
						filePath.includes(templatePath) ||
						fileCache?.frontmatter?.template === templatePath ||
						fileCache?.frontmatter?.templateFile === templatePath
					);
				}
			);

			if (matchesTemplate) {
				return {
					name: "template",
					criteria: templateConfig.templatePaths.join(", "),
				};
			}
		}

		return null;
	}

	/**
	 * Generate task content based on configuration
	 */
	private generateTaskContent(
		filePath: string,
		fileContent: string,
		fileCache: CachedMetadata | null
	): string {
		const config = this.config.getConfig().fileTaskProperties;
		const fileName = filePath.split("/").pop() || filePath;
		const fileNameWithoutExt = fileName.replace(/\.[^/.]+$/, "");

		switch (config.contentSource) {
			case "filename":
				// If user prefers frontmatter title, show it over filename
				if (
					config.preferFrontmatterTitle &&
					fileCache?.frontmatter?.title
				) {
					return fileCache.frontmatter.title as string;
				}
				return config.stripExtension ? fileNameWithoutExt : fileName;

			case "title":
				// Always prefer frontmatter title if available, fallback to filename without extension
				return (
					(fileCache?.frontmatter?.title as string) ||
					fileNameWithoutExt
				);

			case "h1":
				const h1 = fileCache?.headings?.find((h) => h.level === 1);
				return (h1?.heading as string) || fileNameWithoutExt;

			case "custom":
				if (config.customContentField && fileCache?.frontmatter) {
					const val =
						fileCache.frontmatter[config.customContentField];
					if (val) return val as string;
					// If custom field not present, optionally prefer frontmatter title
					if (
						config.preferFrontmatterTitle &&
						fileCache.frontmatter.title
					) {
						return fileCache.frontmatter.title as string;
					}
					return fileNameWithoutExt;
				}
				// No custom field specified: optionally prefer frontmatter title
				if (
					config.preferFrontmatterTitle &&
					fileCache?.frontmatter?.title
				) {
					return fileCache.frontmatter.title as string;
				}
				return fileNameWithoutExt;

			default:
				// Default to respecting preferFrontmatterTitle when available
				if (
					config.preferFrontmatterTitle &&
					fileCache?.frontmatter?.title
				) {
					return fileCache.frontmatter.title as string;
				}
				return config.stripExtension ? fileNameWithoutExt : fileName;
		}
	}

	/**
	 * Compute task status symbol from raw metadata value
	 * Maps textual status values (e.g., "completed", "in-progress") to task status symbols (e.g., "x", "/")
	 */
	private computeStatusSymbol(
		rawStatus: string | undefined,
		defaultStatus: string
	): string {
		if (!rawStatus) return defaultStatus;
		// Already a single-character mark
		if (rawStatus.length === 1) return rawStatus;

		const sm = this.config.getConfig().statusMapping;
		const target = sm.caseSensitive
			? rawStatus
			: String(rawStatus).toLowerCase();

		// Try configured metadata->symbol table first
		for (const [k, sym] of Object.entries(sm.metadataToSymbol || {})) {
			const key = sm.caseSensitive ? k : k.toLowerCase();
			if (key === target) return sym;
		}

		// Fallback to common defaults to be robust
		const norm = String(rawStatus).toLowerCase();
		const defaultMapping = FileSource.DEFAULT_STATUS_MAPPINGS[norm];
		if (defaultMapping !== undefined) return defaultMapping;

		return defaultStatus;
	}

	/**
	 * Extract task metadata from file
	 * Returns metadata along with rawStatus for status symbol computation
	 */
	private extractTaskMetadata(
		filePath: string,
		fileContent: string,
		fileCache: CachedMetadata | null,
		strategy: { name: RecognitionStrategy; criteria: string }
	): Partial<FileSourceTaskMetadata> & { rawStatus?: string } {
		const config = this.config.getConfig();
		const frontmatter = fileCache?.frontmatter || {};
		const resolvedFrontmatter = this.applyMetadataMappings(
			frontmatter,
			config.metadataMappings
		);

		// Extract raw status value from frontmatter for later symbol mapping
		const rawStatusVal = resolvedFrontmatter.status ?? "";
		const rawStatus: string = typeof rawStatusVal === "string" ? rawStatusVal : String(rawStatusVal ?? "");

		// TODO: Future enhancement - read frontmatter.repeat and map into FileSourceTaskMetadata (e.g., as recurrence)

		// Collect all tags (from file cache and frontmatter)
		const allTags = this.mergeTags(
			fileCache?.tags?.map((tag) => tag.tag) || [],
			resolvedFrontmatter.tags
		);

		// Extract project from tags as a fallback (only if not in frontmatter)
		// Note: In FileSource mode, context and area come ONLY from frontmatter,
		// not from tags like #context/xxx or #area/xxx
		const projectTagExtraction = this.extractProjectFromTags(allTags);
		const projectFromTags = projectTagExtraction.project;

		// Priority order for project:
		// 1. Direct frontmatter field (project: xxx) - highest priority
		// 2. Metadata mapping (e.g., custom_project mapped to project via metadataMappings)
		// 3. Tag extraction (#project/xxx) - lowest priority, only if frontmatter has nothing
		const projectVal = resolvedFrontmatter.project ?? projectFromTags;
		let projectValue: string | undefined;
		if (projectVal === true) {
			const fileName = filePath.split("/").pop() || filePath;
			projectValue = fileName.replace(/\.md$/i, "");
		} else if (typeof projectVal === "string" && projectVal.trim()) {
			projectValue = projectVal.trim();
		}

		const shouldStripProjectTags =
			!resolvedFrontmatter.project &&
			Boolean(projectFromTags) &&
			projectTagExtraction.matchedTags.length > 0;
		const tagsForMetadata = shouldStripProjectTags
			? allTags.filter(
					(tag) => !projectTagExtraction.matchedTags.includes(tag)
			  )
			: allTags;

		// Extract standard task metadata
		const metadata: Partial<FileSourceTaskMetadata> = {
			dueDate: this.parseDate(
				resolvedFrontmatter.dueDate ?? resolvedFrontmatter.due
			),
			startDate: this.parseDate(
				resolvedFrontmatter.startDate ?? resolvedFrontmatter.start
			),
			scheduledDate: this.parseDate(
				resolvedFrontmatter.scheduledDate ??
					resolvedFrontmatter.scheduled
			),
			completedDate: this.parseDate(resolvedFrontmatter.completedDate),
			createdDate: this.parseDate(resolvedFrontmatter.createdDate),
			recurrence:
				typeof resolvedFrontmatter.recurrence === "string"
					? resolvedFrontmatter.recurrence
					: (resolvedFrontmatter.recurrence != null
						? String(resolvedFrontmatter.recurrence)
						: undefined),
			priority:
				this.parsePriority(resolvedFrontmatter.priority) ??
				config.fileTaskProperties.defaultPriority,
			// Project: frontmatter (direct or mapped) > tags (#project/xxx)
			project: projectValue,
			// Context and area: ONLY from frontmatter (direct or mapped via metadataMappings)
			context:
				resolvedFrontmatter.context !== undefined &&
				resolvedFrontmatter.context !== null
					? String(resolvedFrontmatter.context)
					: undefined,
			area:
				resolvedFrontmatter.area !== undefined &&
				resolvedFrontmatter.area !== null
					? String(resolvedFrontmatter.area)
					: undefined,
			tags: tagsForMetadata,
			children: [],
		};

		// Return metadata with rawStatus for status computation in buildFileTask
		return { ...metadata, rawStatus };
	}

	/**
	 * Extract project from tags
	 * Only extracts #project/xxx format tags as a fallback when frontmatter doesn't have project
	 * Note: context and area are NOT extracted from tags in FileSource mode,
	 * they should be defined directly in frontmatter (context: xxx, area: xxx)
	 */
	private extractProjectFromTags(tags: string[]): {
		project?: string;
		matchedTags: string[];
	} {
		// Get configurable project prefix from plugin settings, with fallback default
		const configuredPrefix =
			this.plugin?.settings?.projectTagPrefix?.["tasks"];
		const projectPrefix =
			typeof configuredPrefix === "string" && configuredPrefix.trim()
				? configuredPrefix.trim()
				: "project";

		const matchedTags: string[] = [];
		let projectValue: string | undefined;

		for (const tag of tags) {
			if (!tag || typeof tag !== "string") continue;

			// Remove leading # if present
			const tagWithoutHash = tag.startsWith("#") ? tag.substring(1) : tag;

			// Check for project tags (case-insensitive prefix match)
			if (
				tagWithoutHash
					.toLowerCase()
					.startsWith(`${projectPrefix.toLowerCase()}/`)
			) {
				matchedTags.push(tag);
				if (!projectValue) {
					// Extract the value using the actual prefix length (preserving case in the value)
					const slashIndex = tagWithoutHash.indexOf("/");
					if (slashIndex !== -1) {
						const value = tagWithoutHash.substring(slashIndex + 1);
						if (value) {
							projectValue = value;
						}
					}
				}
			}
		}

		if (projectValue) {
			console.log(
				`[FileSource] Extracted project from tag: ${projectValue}`
			);
		}

		return { project: projectValue, matchedTags };
	}

	/**
	 * Apply configured metadata mappings to normalize frontmatter keys
	 */
	private applyMetadataMappings(
		frontmatter: Record<string, any>,
		mappings: MetadataMappingConfig[]
	): Record<string, any> {
		if (!Array.isArray(mappings) || mappings.length === 0) {
			return { ...frontmatter };
		}

		const result = { ...frontmatter };

		for (const mapping of mappings) {
			if (!mapping?.enabled) continue;
			const sourceKey = mapping.sourceKey;
			const targetKey = mapping.targetKey;
			if (!sourceKey || !targetKey) continue;

			const value = frontmatter[sourceKey];
			if (value !== undefined) {
				result[targetKey] = value;
			}
		}

		return result;
	}

	/**
	 * Merge vault tags with mapped frontmatter tag values
	 */
	private mergeTags(existing: string[], extra: unknown): string[] {
		const tagSet = new Set(existing);

		if (Array.isArray(extra)) {
			for (const value of extra) {
				if (typeof value !== "string") continue;
				const normalized = this.normalizeTag(value);
				if (normalized) tagSet.add(normalized);
			}
		} else if (typeof extra === "string") {
			const segments = extra
				.split(/[,\s]+/)
				.map((segment) => this.normalizeTag(segment))
				.filter((segment): segment is string => Boolean(segment));

			for (const segment of segments) {
				tagSet.add(segment);
			}
		}

		return Array.from(tagSet);
	}

	private normalizeTag(value: string): string | null {
		const trimmed = value.trim();
		if (!trimmed) return null;
		return trimmed.startsWith("#") ? trimmed : `#${trimmed}`;
	}

	private parsePriority(value: unknown): number | undefined {
		if (value === undefined || value === null) {
			return undefined;
		}
		if (typeof value === "number" && !Number.isNaN(value)) {
			return value;
		}
		if (typeof value === "string") {
			const trimmed = value.trim();
			if (!trimmed) return undefined;
			const parsed = Number(trimmed);
			if (!Number.isNaN(parsed)) {
				return parsed;
			}
		}
		return undefined;
	}

	/**
	 * Parse date from various formats
	 */
	private parseDate(dateValue: any): number | undefined {
		if (!dateValue) return undefined;

		if (typeof dateValue === "number") {
			return dateValue;
		}

		if (typeof dateValue === "string") {
			const parsed = Date.parse(dateValue);
			return isNaN(parsed) ? undefined : parsed;
		}

		if (dateValue instanceof Date) {
			return dateValue.getTime();
		}

		return undefined;
	}

	/**
	 * Update file task cache
	 */
	private updateFileTaskCache(
		filePath: string,
		task: Task<FileSourceTaskMetadata>
	): void {
		const frontmatterHash = this.generateFrontmatterHash(filePath);

		this.fileTaskCache.set(filePath, {
			fileTaskExists: true,
			frontmatterHash,
			childTaskIds: new Set(task.metadata.childTasks || []),
			lastUpdated: Date.now(),
		});
	}

	/**
	 * Generate hash for frontmatter for change detection
	 */
	private generateFrontmatterHash(filePath: string): string {
		const file = this.app.vault.getAbstractFileByPath(filePath) as TFile;
		if (!file) return "";

		const fileCache = this.app.metadataCache.getFileCache(file);
		if (!fileCache?.frontmatter) return "";

		// Simple hash of frontmatter JSON
		const frontmatterStr = JSON.stringify(
			fileCache.frontmatter,
			Object.keys(fileCache.frontmatter).sort()
		);
		return this.simpleHash(frontmatterStr);
	}

	/**
	 * Simple hash function
	 */
	private simpleHash(str: string): string {
		let hash = 0;
		for (let i = 0; i < str.length; i++) {
			const char = str.charCodeAt(i);
			hash = (hash << 5) - hash + char;
			hash = hash & hash; // Convert to 32-bit integer
		}
		return hash.toString(36);
	}

	/**
	 * Check if file needs updating (stub for Phase 2)
	 */
	private shouldUpdateFileTask(
		filePath: string,
		changeType: "metadata" | "content"
	): boolean {
		// Simple check for Phase 1 - always update if file is tracked
		return this.fileTaskCache.has(filePath);
	}

	/**
	 * Update statistics
	 */
	private updateStatistics(
		strategy: RecognitionStrategy,
		delta: number
	): void {
		this.stats.recognitionBreakdown[strategy] += delta;
		this.stats.trackedFileCount += delta;
		this.stats.lastUpdate = Date.now();
		this.stats.lastUpdateSeq = this.lastUpdateSeq;
	}

	/**
	 * Emit file task update event
	 */
	private emitFileTaskUpdate(
		action: "created" | "updated" | "removed",
		task: Task<FileSourceTaskMetadata>
	): void {
		const seq = Seq.next();
		this.lastUpdateSeq = seq;

		emit(this.app, Events.FILE_TASK_UPDATED, {
			action,
			task,
			timestamp: Date.now(),
			seq,
		});

		console.log(`[FileSource] File task ${action}: ${task.filePath}`);
	}

	/**
	 * Check if file is relevant for processing
	 */
	private isRelevantFile(filePath: string): boolean {
		// Fast-path filters first
		// Only process markdown files for now (additional file type support can be added later)
		if (!filePath.endsWith(".md")) {
			return false;
		}

		// Skip system/hidden files
		if (filePath.startsWith(".") || filePath.includes("/.")) {
			return false;
		}

		// Apply centralized FileFilterManager for 'file' scope filtering if available
		if (this.fileFilterManager) {
			const include = this.fileFilterManager.shouldIncludePath(
				filePath,
				"file"
			);
			if (!include) return false;
		}

		return true;
	}

	/**
	 * Perform initial scan of existing files
	 */
	private async performInitialScan(): Promise<void> {
		console.log("[FileSource] Performing initial scan...");

		const mdFiles = this.app.vault.getMarkdownFiles();
		console.log(
			`[FileSource] Found ${mdFiles.length} markdown files to check`
		);

		let scannedCount = 0;
		let taskCount = 0;
		let relevantCount = 0;

		for (const file of mdFiles) {
			if (this.isRelevantFile(file.path)) {
				relevantCount++;
				try {
					const shouldBeTask = await this.shouldCreateFileTask(
						file.path
					);
					if (shouldBeTask) {
						const task = await this.createFileTask(file.path);
						if (task) {
							taskCount++;
						}
					}
					scannedCount++;
				} catch (error) {
					console.error(
						`[FileSource] Error scanning ${file.path}:`,
						error
					);
				}
			}
		}

		console.log(
			`[FileSource] Initial scan complete: ${mdFiles.length} total files, ${relevantCount} relevant, ${scannedCount} scanned, ${taskCount} file tasks created`
		);

		if (taskCount === 0 && relevantCount > 0) {
			console.log(
				`[FileSource] No file tasks created. Check if your files match the configured recognition strategies:`
			);
			const config = this.config.getConfig();
			if (config.recognitionStrategies.metadata.enabled) {
				console.log(
					`[FileSource] - Metadata strategy: requires frontmatter with fields: ${config.recognitionStrategies.metadata.taskFields.join(
						", "
					)}`
				);
			}
			if (config.recognitionStrategies.tags.enabled) {
				console.log(
					`[FileSource] - Tag strategy: requires tags: ${config.recognitionStrategies.tags.taskTags.join(
						", "
					)}`
				);
			}
			if (config.recognitionStrategies.paths.enabled) {
				console.log(
					`[FileSource] - Path strategy: requires files in paths: ${config.recognitionStrategies.paths.taskPaths.join(
						", "
					)}`
				);
			}
		}
	}

	/**
	 * Handle configuration changes
	 */
	private handleConfigChange(newConfig: FileSourceConfiguration): void {
		if (!newConfig.enabled && this.isInitialized) {
			// FileSource is being disabled
			this.destroy();
			return;
		}

		if (newConfig.enabled && !this.isInitialized) {
			// FileSource is being enabled
			this.initialize();
			return;
		}

		// Configuration changed while active - might need to rescan
		// This is a Phase 2 enhancement
		console.log("[FileSource] Configuration updated");
	}

	/**
	 * Get current statistics
	 */
	getStats(): FileSourceStats {
		return { ...this.stats };
	}

	/**
	 * Get all file tasks (stub for Phase 2)
	 */
	async getAllFileTasks(): Promise<Task<FileSourceTaskMetadata>[]> {
		// This will be implemented properly in Phase 3 with Repository integration
		return [];
	}

	/**
	 * Update configuration
	 */
	updateConfiguration(config: Partial<FileSourceConfiguration>): void {
		this.config.updateConfig(config);
	}

	/**
	 * Sync FileSource status mapping from plugin TaskStatus settings
	 */
	public syncStatusMappingFromSettings(
		taskStatuses: Record<string, string>
	): void {
		try {
			this.config.syncWithTaskStatuses(taskStatuses);
		} catch (e) {
			console.warn(
				"[FileSource] Failed to sync status mapping from settings",
				e
			);
		}
	}

	/**
	 * Alias for updateConfiguration to match expected interface
	 */
	updateConfig(config: Partial<FileSourceConfiguration>): void {
		this.updateConfiguration(config);
	}

	/**
	 * Force refresh of all file tasks
	 */
	async refresh(): Promise<void> {
		if (!this.isInitialized || !this.config.isEnabled()) return;

		// Clear cache and re-scan
		this.fileTaskCache.clear();
		this.stats.trackedFileCount = 0;
		this.stats.recognitionBreakdown = {
			metadata: 0,
			tag: 0,
			template: 0,
			path: 0,
		};

		await this.performInitialScan();
	}

	/**
	 * Cleanup and destroy FileSource
	 */
	destroy(): void {
		if (!this.isInitialized) return;

		console.log("[FileSource] Destroying FileSource...");

		// Clear all debouncing timeouts
		for (const timeout of this.pendingUpdates.values()) {
			clearTimeout(timeout);
		}
		this.pendingUpdates.clear();

		// Clear event listeners
		for (const ref of this.eventRefs) {
			this.app.vault.offref(ref);
		}
		this.eventRefs = [];

		// Clear cache
		this.fileTaskCache.clear();

		// Reset statistics
		this.stats = {
			initialized: false,
			trackedFileCount: 0,
			recognitionBreakdown: { metadata: 0, tag: 0, template: 0, path: 0 },
			lastUpdate: 0,
			lastUpdateSeq: 0,
		};

		// Emit cleanup event
		emit(this.app, Events.FILE_TASK_REMOVED, {
			filePath: null, // Indicates all file tasks removed
			timestamp: Date.now(),
			seq: Seq.next(),
			destroyed: true,
		});

		this.isInitialized = false;

		console.log("[FileSource] Cleanup complete");
	}

	/**
	 * Cleanup resources and stop listening to events
	 */
	cleanup(): void {
		// Unsubscribe from all events
		this.eventRefs.forEach((ref) => {
			if (
				this.app.workspace &&
				typeof this.app.workspace.offref === "function"
			) {
				this.app.workspace.offref(ref);
			}
		});
		this.eventRefs = [];

		// Clear pending updates
		this.pendingUpdates.forEach((timeout) => clearTimeout(timeout));
		this.pendingUpdates.clear();

		// Clear cache
		this.fileTaskCache.clear();

		// Reset state
		this.isInitialized = false;
		this.stats.initialized = false;

		console.log("[FileSource] Cleaned up and stopped");
	}
}