import { writable } from 'svelte/store';
import type { Feed, FeedEntry } from './types';

// Create a store for feeds
function createFeedsStore() {
	const { subscribe, set, update } = writable<Feed[]>([]);

	// Create a store object with methods
	const store = {
		subscribe,
		load: async (): Promise<Feed[]> => {
			try {
				const response = await fetch('/api/feeds');
				if (!response.ok) {
					throw new Error(`Failed to load feeds: ${response.statusText}`);
				}
				const feeds = await response.json();
				// Convert date strings to Date objects
				const processedFeeds = feeds.map(
					(
						feed: Omit<Feed, 'lastFetched' | 'createdAt' | 'updatedAt'> & {
							lastFetched?: string;
							createdAt: string;
							updatedAt: string;
						}
					) => ({
						...feed,
						lastFetched: feed.lastFetched ? new Date(feed.lastFetched) : undefined,
						createdAt: new Date(feed.createdAt),
						updatedAt: new Date(feed.updatedAt)
					})
				);
				set(processedFeeds);
				return processedFeeds;
			} catch (error) {
				console.error('Error loading feeds:', error);
				throw error;
			}
		},
		add: async (url: string): Promise<Feed> => {
			try {
				const response = await fetch('/api/feeds', {
					method: 'POST',
					headers: {
						'Content-Type': 'application/json'
					},
					body: JSON.stringify({ url })
				});

				if (!response.ok) {
					throw new Error(`Failed to add feed: ${response.statusText}`);
				}

				const newFeed = await response.json();
				// Convert date strings to Date objects
				const processedFeed = {
					...newFeed,
					lastFetched: newFeed.lastFetched ? new Date(newFeed.lastFetched) : undefined,
					createdAt: new Date(newFeed.createdAt),
					updatedAt: new Date(newFeed.updatedAt)
				};

				update((feeds) => [...feeds, processedFeed]);
				return processedFeed;
			} catch (error) {
				console.error('Error adding feed:', error);
				throw error;
			}
		},
		delete: async (id: string): Promise<void> => {
			try {
				const response = await fetch(`/api/feeds/${id}`, {
					method: 'DELETE'
				});

				if (!response.ok) {
					throw new Error(`Failed to delete feed: ${response.statusText}`);
				}

				update((feeds) => feeds.filter((feed) => feed.id !== id));
			} catch (error) {
				console.error('Error deleting feed:', error);
				throw error;
			}
		},
		refresh: async (id?: string): Promise<void> => {
			try {
				const endpoint = id ? `/api/feeds/${id}/refresh` : '/api/feeds/refresh';
				const response = await fetch(endpoint, {
					method: 'POST'
				});

				if (!response.ok) {
					throw new Error(`Failed to refresh feeds: ${response.statusText}`);
				}

				// Reload feeds to get updated data
				await store.load();
			} catch (error) {
				console.error('Error refreshing feeds:', error);
				throw error;
			}
		},
		importOPML: async (file: File): Promise<{ imported: number }> => {
			try {
				// Validate file type
				if (
					!file.name.toLowerCase().endsWith('.opml') &&
					!file.name.toLowerCase().endsWith('.xml')
				) {
					throw new Error('Please select a valid OPML or XML file');
				}

				// Validate file size (max 10MB)
				const maxSize = 10 * 1024 * 1024; // 10MB
				if (file.size > maxSize) {
					throw new Error('File size exceeds the maximum limit of 10MB');
				}

				console.log('Importing OPML file:', file.name, 'Size:', file.size, 'Type:', file.type);

				const formData = new FormData();
				formData.append('file', file);

				try {
					const response = await fetch('/api/feeds/import', {
						method: 'POST',
						body: formData
					});

					console.log('OPML import response status:', response.status, response.statusText);

					// Log headers in a type-safe way
					const headerLog: Record<string, string> = {};
					response.headers.forEach((value, key) => {
						headerLog[key] = value;
					});
					console.log('OPML import response headers:', headerLog);

					// Handle non-OK responses
					if (!response.ok) {
						const contentType = response.headers.get('content-type');
						console.log('OPML import error content-type:', contentType);

						if (contentType && contentType.includes('application/json')) {
							// Try to parse error as JSON
							try {
								const errorData = await response.json();
								console.log('OPML import error data:', errorData);
								throw new Error(errorData.error || `Failed to import OPML: ${response.statusText}`);
							} catch (jsonError) {
								console.error('Error parsing JSON error response:', jsonError);
								throw new Error(
									`Failed to import OPML: ${response.statusText} (Error parsing error response)`
								);
							}
						} else {
							// Handle non-JSON responses
							try {
								const text = await response.text();
								console.log('OPML import error text (first 200 chars):', text.substring(0, 200));
								throw new Error(
									`Server returned HTML instead of JSON. Status: ${response.status} ${response.statusText}`
								);
							} catch (textError) {
								console.error('Error reading response text:', textError);
								throw new Error(
									`Failed to import OPML: ${response.statusText} (Could not read response)`
								);
							}
						}
					}

					const result = await response.json();
					console.log('OPML import success:', result);

					// Reload feeds to get the newly imported ones
					await store.load();

					return result;
				} catch (fetchError) {
					console.error('OPML import fetch error:', fetchError);
					throw fetchError;
				}
			} catch (error) {
				console.error('Error importing OPML:', error);
				throw error;
			}
		},
		importOPMLFromURL: async (url: string): Promise<{ imported: number }> => {
			try {
				const response = await fetch('/api/feeds/import-url', {
					method: 'POST',
					headers: {
						'Content-Type': 'application/json'
					},
					body: JSON.stringify({ url })
				});

				if (!response.ok) {
					throw new Error(`Failed to import OPML from URL: ${response.statusText}`);
				}

				const result = await response.json();

				// Reload feeds to get the newly imported ones
				await store.load();

				return result;
			} catch (error) {
				console.error('Error importing OPML from URL:', error);
				throw error;
			}
		}
	};

	return store;
}

// Create a store for feed entries
function createEntriesStore() {
	const { subscribe, set, update } = writable<FeedEntry[]>([]);

	return {
		subscribe,
		loadEntries: async (feedId?: string, unreadOnly = false): Promise<FeedEntry[]> => {
			try {
				const params = new URLSearchParams();
				if (feedId) params.append('feedId', feedId);
				if (unreadOnly) params.append('unreadOnly', 'true');

				const response = await fetch(`/api/feeds/entries?${params.toString()}`);
				if (!response.ok) throw new Error('Failed to load entries');

				const data = await response.json();
				const entries = data.map((entry: FeedEntry) => ({
					...entry,
					published: entry.published ? new Date(entry.published) : null,
					updated: entry.updated ? new Date(entry.updated) : null,
					readAt: entry.readAt ? new Date(entry.readAt) : null
				}));
				set(entries);
				return entries;
			} catch (error) {
				console.error('Error loading entries:', error);
				throw error;
			}
		},
		getEntry: async (id: string): Promise<FeedEntry> => {
			try {
				const response = await fetch(`/api/feeds/entries/${id}`);
				if (!response.ok) throw new Error('Failed to load entry');

				const entry = await response.json();
				return {
					...entry,
					published: entry.published ? new Date(entry.published) : null,
					updated: entry.updated ? new Date(entry.updated) : null,
					readAt: entry.readAt ? new Date(entry.readAt) : null
				};
			} catch (error) {
				console.error('Error loading entry:', error);
				throw error;
			}
		},
		markAsRead: async (id: string): Promise<void> => {
			try {
				const response = await fetch(`/api/feeds/entries/${id}/read`, {
					method: 'POST'
				});
				if (!response.ok) throw new Error('Failed to mark entry as read');

				// Update the entry in the store
				update((entries) => {
					return entries.map((entry) => {
						if (entry.id === id) {
							return { ...entry, readAt: new Date() };
						}
						return entry;
					});
				});
			} catch (error) {
				console.error('Error marking entry as read:', error);
				throw error;
			}
		},
		markAllAsRead: async (feedId?: string): Promise<void> => {
			try {
				const params = new URLSearchParams();
				if (feedId) params.append('feedId', feedId);

				const response = await fetch(`/api/feeds/entries/read-all?${params.toString()}`, {
					method: 'POST'
				});
				if (!response.ok) throw new Error('Failed to mark all entries as read');

				// Update all entries in the store
				update((entries) => {
					return entries.map((entry) => {
						if (!entry.readAt && (!feedId || entry.feedId === feedId)) {
							return { ...entry, readAt: new Date() };
						}
						return entry;
					});
				});
			} catch (error) {
				console.error('Error marking all entries as read:', error);
				throw error;
			}
		},
		fetchFullContent: async (id: string): Promise<void> => {
			try {
				const response = await fetch(`/api/feeds/entries/${id}/full-content`, {
					method: 'POST'
				});
				if (!response.ok) throw new Error('Failed to fetch full content');
			} catch (error) {
				console.error('Error fetching full content:', error);
				throw error;
			}
		}
	};
}

export const feeds = createFeedsStore();
export const entries = createEntriesStore();