import BaseClient from 'remotestoragejs/release/types/baseclient';
import Geohash from 'latlon-geohash';
import { ulid } from 'ulid';
import { FromSchema } from 'json-schema-to-ts';

const placeSchema = {
  type: 'object',
  properties: {
    id: { type: 'string' },
    title: { type: 'string' },
    lat: { type: 'number' },
    lon: { type: 'number' },
    geohash: { type: 'string' },
    zoom: { type: 'number' },
    url: { type: 'string' },
    osmId: { type: 'string' },
    osmType: { type: 'string' },
    osmTags: {
      type: 'object',
      additionalProperties: { type: 'string' },
    },
    description: { type: 'string' },
    tags: {
      type: 'array',
      items: { type: 'string' },
      default: [],
    },
    createdAt: { type: 'string', format: 'date-time' },
    updatedAt: { type: 'string', format: 'date-time' },
  },
  required: ['id', 'title', 'lat', 'lon', 'geohash', 'createdAt'],
} as const;

const listSchema = {
  type: 'object',
  properties: {
    id: { type: 'string' },
    title: { type: 'string' },
    color: { type: 'string' },
    placeRefs: {
      type: 'array',
      items: {
        type: 'object',
        properties: {
          id: { type: 'string' },
          geohash: { type: 'string' },
        },
        required: ['id', 'geohash'],
      },
      default: [],
    },
    createdAt: { type: 'string', format: 'date-time' },
    updatedAt: { type: 'string', format: 'date-time' },
  },
  required: ['id', 'title', 'placeRefs', 'createdAt'],
} as const;

export type List = FromSchema<typeof listSchema> & { [key: string]: any };

/**
 * Represents a Place object.
 *
 * Core properties enforced by schema:
 * - `id`: Unique identifier (ULID)
 * - `title`: Name of the place
 * - `lat`: Latitude
 * - `lon`: Longitude
 * - `geohash`: Geohash for indexing
 * - `createdAt`: ISO date string
 *
 * Optional properties:
 * - `description`: Text description
 * - `zoom`: Map zoom level
 * - `url`: Related URL
 * - `osmId`, `osmType`, `osmTags`: OpenStreetMap data
 * - `tags`: Array of string tags
 * - `updatedAt`: ISO date string
 */
export type Place = FromSchema<typeof placeSchema> & { [key: string]: any };

export interface PlacesClient {
  /**
   * Store a place.
   * Generates ID and Geohash if missing.
   * Path structure: `<geohash-prefix-2>/<geohash-prefix-2>/<id>`
   *
   * @param placeData - The data of the place to store.
   * @returns The stored place object.
   */
  store(placeData: Partial<Place>): Promise<Place>;

  /**
   * Remove a place.
   * Requires geohash to locate the folder.
   *
   * @param id - The ID of the place to remove.
   * @param geohash - The geohash of the place.
   */
  remove(id: string, geohash: string): Promise<unknown>;

  /**
   * Get a single place.
   * Requires geohash to locate the folder.
   *
   * @param id - The ID of the place to retrieve.
   * @param geohash - The geohash of the place.
   * @returns The place object.
   */
  get(id: string, geohash: string): Promise<Place | unknown>;

  /**
   * List places matching a geohash prefix.
   * Supports 2-char ("ab") or 4-char ("abcd") prefixes.
   * If 2-char, it returns the sub-folders (prefixes), not places.
   * If 4-char, it returns the places in that sector.
   *
   * @param prefix - The geohash prefix to filter by.
   * @returns A map of objects found at the prefix.
   */
  listByPrefix(prefix: string): Promise<unknown | { [key: string]: any }>;

  /**
   * Get places from specific prefixes.
   *
   * @param prefixes - Optional array of 4-character geohash prefixes to load (e.g. ['w1q7', 'w1q8']).
   *                 If not provided, it will attempt to scan ALL prefixes (recursive).
   * @returns An array of places.
   */
  getPlaces(prefixes?: string[]): Promise<Place[]>;

  lists: {
    /**
     * Get all lists.
     * @returns Array of List objects.
     */
    getAll(): Promise<List[]>;

    /**
     * Get a single list by ID (slug).
     * @param id - The slug ID of the list.
     */
    get(id: string): Promise<List | null>;

    /**
     * Create or update a list.
     * @param id - The slug ID (e.g., "to-go").
     * @param title - Human readable title.
     * @param color - Optional hex color code.
     */
    create(id: string, title: string, color?: string): Promise<List>;

    /**
     * Delete a list.
     * @param id - The slug ID of the list.
     */
    delete(id: string): Promise<void>;

    /**
     * Add or remove a place from a list.
     * @param listId - The slug ID of the list.
     * @param placeId - The ID of the place.
     * @param geohash - The geohash of the place (needed for reference).
     */
    togglePlace(
      listId: string,
      placeId: string,
      geohash: string
    ): Promise<List>;
  };
}

const Places = function (
  privateClient: BaseClient /*, publicClient: BaseClient */
): { exports: PlacesClient } {
  // Define Schema
  privateClient.declareType('place', placeSchema as any);
  privateClient.declareType('list', listSchema as any);

  // Helper to normalize place object
  function preparePlace(data: Partial<Place>): Place {
    const now = new Date().toISOString();
    const id = data.id || ulid();

    // Ensure essential data is present before processing (runtime check for safety, though caller should validate)
    // We default to 0/0 if missing to satisfy TS, relying on schema validation later if really empty
    const lat = typeof data.lat === 'number' ? data.lat : 0;
    const lon = typeof data.lon === 'number' ? data.lon : 0;
    const title = data.title || 'Untitled Place';

    // Compute full precision geohash (default from library is usually 9-10 chars)
    const geohash = data.geohash || Geohash.encode(lat, lon, 10);

    const place: Place = {
      ...data,
      id,
      lat,
      lon,
      geohash,
      title,
      tags: data.tags || [],
      createdAt: data.createdAt || now,
      updatedAt: data.id ? now : undefined,
    };

    // Explicitly remove undefined fields (like URL) so storeObject validation doesn't fail on them
    // RemoteStorage schemas are strict about types; undefined is not a string.
    Object.keys(place).forEach((key) => {
      if (place[key] === undefined) {
        delete place[key];
      }
    });

    return place;
  }

  // Get path for a place based on its geohash (group by first 4 chars: 2+2)
  function getPath(geohash: string, id: string): string {
    const p1 = geohash.substring(0, 2);
    const p2 = geohash.substring(2, 4);
    return `${p1}/${p2}/${id}`;
  }

  const lists = {
    async getAll(): Promise<List[]> {
      const result = await privateClient.getAll('_lists/');
      if (!result) return [];
      // Normalize result: remoteStorage.getAll returns { 'slug': object }
      return Object.values(result);
    },

    async get(id: string): Promise<List | null> {
      const path = `_lists/${id}`;
      return privateClient.getObject(path) as Promise<List | null>;
    },

    async create(id: string, title: string, color?: string): Promise<List> {
      const path = `_lists/${id}`;
      let list = (await privateClient.getObject(path)) as List;
      const now = new Date().toISOString();

      if (list) {
        // Update existing
        list.title = title;
        if (color) list.color = color;
        list.updatedAt = now;
      } else {
        // Create new
        list = {
          id,
          title,
          color,
          placeRefs: [],
          createdAt: now,
          updatedAt: now,
        } as List;
      }

      await privateClient.storeObject('list', path, list);
      return list;
    },

    async delete(id: string): Promise<void> {
      await privateClient.remove(`_lists/${id}`);
    },

    async togglePlace(
      listId: string,
      placeId: string,
      geohash: string
    ): Promise<List> {
      const path = `_lists/${listId}`;
      const list = (await privateClient.getObject(path)) as List;

      if (!list) {
        throw new Error(`List not found: ${listId}`);
      }

      const index = list.placeRefs.findIndex((ref: any) => ref.id === placeId);

      if (index !== -1) {
        // Remove
        list.placeRefs.splice(index, 1);
      } else {
        // Add
        list.placeRefs.push({ id: placeId, geohash });
      }

      list.updatedAt = new Date().toISOString();
      await privateClient.storeObject('list', path, list);
      return list;
    },

    async initDefaults(): Promise<void> {
      const defaults = [
        { id: 'to-go', title: 'Want to go', color: '#ff00ff' }, // Magenta
        { id: 'to-do', title: 'To do', color: '#008000' }, // Green
      ];

      for (const def of defaults) {
        const existing = await this.get(def.id);
        if (!existing) {
          await this.create(def.id, def.title, def.color);
        }
      }
    },
  };

  const places = {
    lists,
    /**
     * Store a place.
     * Generates ID and Geohash if missing.
     * Path structure: `<geohash-prefix-2>/<geohash-prefix-2>/<id>`
     */
    store: async function (placeData: Partial<Place>) {
      const place = preparePlace(placeData);
      const path = getPath(place.geohash, place.id);
      await privateClient.storeObject('place', path, place);
      return place;
    },

    /**
     * Remove a place.
     * Requires geohash to locate the folder.
     */
    remove: async function (id: string, geohash: string) {
      if (!id || !geohash) {
        throw new Error('Both id and geohash are required to remove a place');
      }
      const path = getPath(geohash, id);
      return privateClient.remove(path);
    },

    /**
     * Get a single place.
     * Requires geohash to locate the folder.
     */
    get: async function (id: string, geohash: string) {
      if (!id || !geohash) {
        throw new Error('Both id and geohash are required to get a place');
      }
      const path = getPath(geohash, id);
      return privateClient.getObject(path);
    },

    /**
     * List places matching a geohash prefix.
     * Supports 2-char ("ab") or 4-char ("abcd") prefixes.
     * If 2-char, it returns the sub-folders (prefixes), not places.
     * If 4-char, it returns the places in that sector.
     */
    listByPrefix: async function (prefix: string) {
      let path = '';
      if (prefix.length >= 2) {
        path += prefix.substring(0, 2) + '/';
      }
      if (prefix.length >= 4) {
        path += prefix.substring(2, 4) + '/';
      }
      return privateClient.getAll(path);
    },

    /**
     * Get places from specific prefixes.
     * @param prefixes Optional array of 4-character geohash prefixes to load (e.g. ['w1q7', 'w1q8']).
     *                 If not provided, it will attempt to scan ALL prefixes (recursive).
     */
    getPlaces: async function (prefixes?: string[]) {
      const places: Place[] = [];

      // Helper to process a specific 4-char path (e.g. "ab/cd/")
      const fetchPath = async (path: string) => {
        // Use getAll to load objects (places)
        // Set maxAge to false to skip cache check if configured
        const items = await privateClient.getAll(path, false);
        if (items) {
          Object.values(items).forEach((p) => {
            if (p && typeof p === 'object' && !p.toString().endsWith('/')) {
              places.push(p as Place);
            }
          });
        }
      };

      if (prefixes && prefixes.length > 0) {
        // Load specific sectors
        const promises = prefixes.map(async (prefix) => {
          if (prefix.length < 4) return;
          const p1 = prefix.substring(0, 2);
          const p2 = prefix.substring(2, 4);
          await fetchPath(`${p1}/${p2}/`);
        });
        await Promise.all(promises);
      } else {
        // Load EVERYTHING (Recursive scan)

        // Helper to extract keys from a listing result, handling both simple and detailed formats
        const getKeys = (listing: any): string[] => {
          if (!listing || typeof listing !== 'object') return [];

          let target = listing;
          if (listing.items && typeof listing.items === 'object') {
            target = listing.items;
          }

          return Object.keys(target).filter(
            (k) => k.endsWith('/') && !k.startsWith('@')
          );
        };

        // Level 1: xx/
        const level1 = await privateClient.getListing('', false);
        const l1Keys = getKeys(level1);

        await Promise.all(
          l1Keys.map(async (l1Key) => {
            // Level 2: xx/yy/
            const level2 = await privateClient.getListing(l1Key, false);
            const l2Keys = getKeys(level2);

            await Promise.all(
              l2Keys.map(async (l2Key) => {
                // Level 3: Items in xx/yy/
                await fetchPath(l1Key + l2Key);
              })
            );
          })
        );
      }

      return places;
    },
  };

  return { exports: places };
};

export default { name: 'places', builder: Places };