import { defaultConfigurationService } from "../../config/ConfigurationService";
import { ProviderError, SearchFailedError } from "../../models/errors";
import { SearchOptions } from "../../types/search";
import { Logger } from "../../utils/Logger";
import { ImageSearchResult, LocalImage } from "../models";
import { BaseImageProvider } from "../providers/BaseImageProvider";
import { ImageProviderRegistry } from "../providers/ImageProviderRegistry";
import { ImageDownloader } from "../utils/ImageDownloader";

export interface ImageSearchEngineOptions {
  providers?: BaseImageProvider[];
  downloader?: ImageDownloader;
}

/**
 * Central Image Search Engine orchestrator.
 * Manages provider registration, dynamic configuration resolution, provider fallback execution,
 * and passes search results to ImageDownloader for local image caching.
 * Mapped from Python `image_search/engine.py` ImageSearchEngine.
 */
export class ImageSearchEngine {
  private providers: Map<string, BaseImageProvider> = new Map();
  private downloader: ImageDownloader;
  private searchCounter: number = 0;

  constructor(
    providersOrOptions?: BaseImageProvider[] | BaseImageProvider | ImageSearchEngineOptions,
    downloader?: ImageDownloader
  ) {
    if (Array.isArray(providersOrOptions)) {
      this.downloader = downloader ?? new ImageDownloader();
      for (const p of providersOrOptions) {
        this.registerProvider(p);
      }
    } else if (
      providersOrOptions &&
      typeof providersOrOptions === "object" &&
      "providers" in providersOrOptions
    ) {
      const opts = providersOrOptions as ImageSearchEngineOptions;
      this.downloader = opts.downloader ?? new ImageDownloader();
      if (opts.providers) {
        for (const p of opts.providers) {
          this.registerProvider(p);
        }
      }
    } else if (providersOrOptions instanceof BaseImageProvider) {
      this.downloader = downloader ?? new ImageDownloader();
      this.registerProvider(providersOrOptions);
    } else {
      this.downloader = downloader ?? new ImageDownloader();
    }
  }

  /**
   * Register an image provider instance with the engine.
   */
  public registerProvider(provider: BaseImageProvider): void {
    this.providers.set(provider.providerName.toLowerCase().trim(), provider);
  }

  /**
   * Unregister an image provider by name.
   */
  public unregisterProvider(providerName: string): boolean {
    return this.providers.delete(providerName.toLowerCase().trim());
  }

  /**
   * Retrieve a registered image provider instance by name.
   */
  public getProvider(providerName: string): BaseImageProvider | undefined {
    return this.providers.get(providerName.toLowerCase().trim());
  }

  /**
   * List all currently registered image provider names.
   */
  public listProviders(): string[] {
    return Array.from(this.providers.keys());
  }

  public getProviders(): BaseImageProvider[] {
    return Array.from(this.providers.values());
  }

  /**
   * Execute image search across registered image providers with automatic provider fallback.
   *
   * @param query Non-empty search query string.
   * @param options Search options containing numResults, workingDirectory, and requestId.
   * @returns Array of processed LocalImage objects.
   * @throws ProviderError if workingDirectory is missing from options or no providers registered.
   * @throws SearchFailedError if all image search providers fail during fallback.
   */
  public async searchImages(
    query: string,
    options: SearchOptions = {}
  ): Promise<LocalImage[]> {
    if (!query || !query.trim()) {
      return [];
    }

    this.searchCounter += 1;
    const reqId = options.requestId || `IMG-${Math.random().toString(36).substring(2, 6).toUpperCase()}`;
    const startTime = Date.now();
    const requestedProvider = options.provider?.toLowerCase().trim() || "auto";
    const configuredDefault = defaultConfigurationService.getImageDefaultProvider() || "auto";

    Logger.info("[ImageSearch]", `[${reqId}] Image search execution started for query: "${query}"`);

    const workingDir = String(options.workingDirectory || "").trim();
    if (!workingDir) {
      Logger.error(
        "[ImageSearch]",
        `Image search failed: missing workingDirectory parameter.`
      );
      throw new ProviderError("ImageSearchEngine requires a valid workingDirectory in SearchOptions.");
    }

    const availableProviders = Array.from(this.providers.values());
    if (availableProviders.length === 0) {
      Logger.error("[ImageSearch]", `[${reqId}] Image search failed: No image search providers are registered.`);
      throw new ProviderError("No image search providers are registered.");
    }

    // 1. Explicit provider parameter requested (e.g. provider = "serpapi")
    if (requestedProvider !== "auto") {
      const resolved = this.getProvider(requestedProvider);
      if (!resolved) {
        Logger.error("[ImageSearch]", `[${reqId}] Image search failed: Unknown provider '${requestedProvider}'`);
        throw new ProviderError(`Unknown or unregistered image provider: '${options.provider}'`);
      }

      Logger.info(
        "[ImageSearch]",
        `[${reqId}] Provider Selection -> Requested: '${requestedProvider}' | Configured Default: '${configuredDefault}' | Mode: Explicit Provider | Selected: image.${requestedProvider}`
      );

      try {
        return await this.executeWithProvider(resolved, query.trim(), options, reqId, workingDir, startTime);
      } catch (err: unknown) {
        const errMsg = err instanceof Error ? err.message : String(err);
        Logger.error(
          "[ImageSearch]",
          `[${reqId}] Explicit image provider 'image.${requestedProvider}' failed: ${errMsg}. Fallback disabled in Explicit Provider Mode.`
        );
        throw err;
      }
    }

    // 2. Explicit provider mode: Configured default provider from Settings (e.g. Default Image Provider = "serpapi")
    if (configuredDefault !== "auto") {
      const resolved = this.getProvider(configuredDefault);
      if (!resolved) {
        Logger.error("[ImageSearch]", `[${reqId}] Image search failed: Configured default provider '${configuredDefault}' is unknown or unregistered.`);
        throw new ProviderError(`Configured default image provider '${configuredDefault}' is unknown or unregistered.`);
      }

      Logger.info(
        "[ImageSearch]",
        `[${reqId}] Provider Selection -> Requested: 'auto' | Configured Default: '${configuredDefault}' | Mode: Explicit Default Provider | Selected: image.${configuredDefault}`
      );

      try {
        return await this.executeWithProvider(resolved, query.trim(), options, reqId, workingDir, startTime);
      } catch (err: unknown) {
        const errMsg = err instanceof Error ? err.message : String(err);
        Logger.error(
          "[ImageSearch]",
          `[${reqId}] Configured default image provider 'image.${configuredDefault}' failed: ${errMsg}. Fallback disabled in Explicit Provider Mode.`
        );
        throw err;
      }
    }

    // 3. Auto Provider Mode: Both requested and default are "auto". Iterate priority list with fallback.
    return this.executeFallback(query.trim(), options, reqId, requestedProvider, configuredDefault, workingDir, startTime);
  }

  /**
   * Helper method to execute search using a single target image provider.
   */
  private async executeWithProvider(
    targetProvider: BaseImageProvider,
    query: string,
    options: SearchOptions,
    reqId: string,
    workingDir: string,
    startTime: number
  ): Promise<LocalImage[]> {
    const rawResults: ImageSearchResult[] = await targetProvider.searchImages(query, options);

    if (!rawResults || rawResults.length === 0) {
      const durationMs = Date.now() - startTime;
      Logger.info(
        "[ImageSearch]",
        `[${reqId}] Image search completed. Provider: image.${targetProvider.providerName} | Duration: ${durationMs} ms | Results: 0`
      );
      return [];
    }

    const processed = await this.downloader.processResults(
      rawResults,
      targetProvider.providerName,
      workingDir
    );

    const durationMs = Date.now() - startTime;
    Logger.info(
      "[ImageSearch]",
      `[${reqId}] Image search completed. Provider: image.${targetProvider.providerName} | Duration: ${durationMs} ms | Results: ${processed.length}`
    );
    return processed;
  }

  /**
   * Iterate through registered image providers in priority order until one succeeds or all fail.
   */
  private async executeFallback(
    query: string,
    options: SearchOptions,
    reqId: string,
    requestedProvider: string,
    configuredDefault: string,
    workingDir: string,
    startTime: number
  ): Promise<LocalImage[]> {
    const priorityNames = defaultConfigurationService.getImageProviderPriority();
    const priorityIds = priorityNames
      .map((name) => ImageProviderRegistry.getSpec(name)?.id)
      .filter((id) => id !== undefined);
    Logger.info(
      "[ImageSearch]",
      `[${reqId}] Mode: Auto Provider Fallback Chain | Priority IDs: [${priorityIds.join(",")}] | Resolved Order: [${priorityNames.join(", ")}]`
    );
    const attemptedErrors: Record<string, string> = {};

    const orderedProviders: BaseImageProvider[] = [];
    for (const name of priorityNames) {
      const p = this.getProvider(name);
      if (p && !orderedProviders.includes(p)) {
        orderedProviders.push(p);
      }
    }

    if (orderedProviders.length === 0) {
      const noValMsg = "Auto (Priority Order) cannot run because the configured Provider Priority Order contains no valid providers. Update the Provider Priority Order or select a specific provider.";
      Logger.error("[ImageSearch]", `[${reqId}] ${noValMsg}`);
      throw new SearchFailedError(noValMsg, {});
    }

    let lastFailedProvider: string | null = null;
    for (const p of orderedProviders) {
      const strategy = lastFailedProvider
        ? `Fallback (after image.${lastFailedProvider} failed)`
        : "Auto Fallback Chain";
      Logger.info(
        "[ImageSearch]",
        `[${reqId}] Provider Selection -> Requested: '${requestedProvider}' | Configured Default: '${configuredDefault}' | Strategy: ${strategy} | Selected: image.${p.providerName}`
      );

      try {
        return await this.executeWithProvider(p, query, options, reqId, workingDir, startTime);
      } catch (err: unknown) {
        const errMsg = err instanceof Error ? err.message : String(err);
        attemptedErrors[p.providerName] = errMsg;
        lastFailedProvider = p.providerName;
        Logger.warn(
          "[ImageSearch]",
          `[${reqId}] Image provider 'image.${p.providerName}' exhausted/failed: ${errMsg}. Moving to next provider in configured priority order.`
        );
      }
    }

    const errDetails = Object.entries(attemptedErrors)
      .map(([p, msg]) => `${p}: ${msg}`)
      .join("; ");
    Logger.error(
      "[ImageSearch]",
      `[${reqId}] Image search failed across all providers (${orderedProviders.length} attempted). Details: ${errDetails}`
    );
    throw new SearchFailedError(
      `All image search providers failed. Errors: ${errDetails}`,
      attemptedErrors
    );
  }
}

import { defaultConfigurationService } from "../../config/ConfigurationService";
import { ProviderError, SearchFailedError } from "../../models/errors";
import { SearchOptions } from "../../types/search";
import { Logger } from "../../utils/Logger";
import { ImageSearchResult, LocalImage } from "../models";
import { BaseImageProvider } from "../providers/BaseImageProvider";
import { ImageProviderRegistry } from "../providers/ImageProviderRegistry";
import { ImageDownloader } from "../utils/ImageDownloader";

export interface ImageSearchEngineOptions {
  providers?: BaseImageProvider[];
  downloader?: ImageDownloader;
}

/**
 * Central Image Search Engine orchestrator.
 * Manages provider registration, dynamic configuration resolution, provider fallback execution,
 * and passes search results to ImageDownloader for local image caching.
 * Mapped from Python `image_search/engine.py` ImageSearchEngine.
 */
export class ImageSearchEngine {
  private providers: Map<string, BaseImageProvider> = new Map();
  private downloader: ImageDownloader;
  private searchCounter: number = 0;

  constructor(
    providersOrOptions?: BaseImageProvider[] | BaseImageProvider | ImageSearchEngineOptions,
    downloader?: ImageDownloader
  ) {
    if (Array.isArray(providersOrOptions)) {
      this.downloader = downloader ?? new ImageDownloader();
      for (const p of providersOrOptions) {
        this.registerProvider(p);
      }
    } else if (
      providersOrOptions &&
      typeof providersOrOptions === "object" &&
      "providers" in providersOrOptions
    ) {
      const opts = providersOrOptions as ImageSearchEngineOptions;
      this.downloader = opts.downloader ?? new ImageDownloader();
      if (opts.providers) {
        for (const p of opts.providers) {
          this.registerProvider(p);
        }
      }
    } else if (providersOrOptions instanceof BaseImageProvider) {
      this.downloader = downloader ?? new ImageDownloader();
      this.registerProvider(providersOrOptions);
    } else {
      this.downloader = downloader ?? new ImageDownloader();
    }
  }

  /**
   * Register an image provider instance with the engine.
   */
  public registerProvider(provider: BaseImageProvider): void {
    this.providers.set(provider.providerName.toLowerCase().trim(), provider);
  }

  /**
   * Unregister an image provider by name.
   */
  public unregisterProvider(providerName: string): boolean {
    return this.providers.delete(providerName.toLowerCase().trim());
  }

  /**
   * Retrieve a registered image provider instance by name.
   */
  public getProvider(providerName: string): BaseImageProvider | undefined {
    return this.providers.get(providerName.toLowerCase().trim());
  }

  /**
   * List all currently registered image provider names.
   */
  public listProviders(): string[] {
    return Array.from(this.providers.keys());
  }

  public getProviders(): BaseImageProvider[] {
    return Array.from(this.providers.values());
  }

  /**
   * Execute image search across registered image providers with automatic provider fallback.
   *
   * @param query Non-empty search query string.
   * @param options Search options containing numResults, workingDirectory, and requestId.
   * @returns Array of processed LocalImage objects.
   * @throws ProviderError if workingDirectory is missing from options or no providers registered.
   * @throws SearchFailedError if all image search providers fail during fallback.
   */
  public async searchImages(
    query: string,
    options: SearchOptions = {}
  ): Promise<LocalImage[]> {
    if (!query || !query.trim()) {
      return [];
    }

    this.searchCounter += 1;
    const reqId = options.requestId || `IMG-${Math.random().toString(36).substring(2, 6).toUpperCase()}`;
    const startTime = Date.now();
    const requestedProvider = options.provider?.toLowerCase().trim() || "auto";
    const configuredDefault = defaultConfigurationService.getImageDefaultProvider() || "auto";

    Logger.info("[ImageSearch]", `[${reqId}] Image search execution started for query: "${query}"`);

    const workingDir = String(options.workingDirectory || "").trim();
    if (!workingDir) {
      Logger.error(
        "[ImageSearch]",
        `Image search failed: missing workingDirectory parameter.`
      );
      throw new ProviderError("ImageSearchEngine requires a valid workingDirectory in SearchOptions.");
    }

    const availableProviders = Array.from(this.providers.values());
    if (availableProviders.length === 0) {
      Logger.error("[ImageSearch]", `[${reqId}] Image search failed: No image search providers are registered.`);
      throw new ProviderError("No image search providers are registered.");
    }

    // 1. Explicit provider parameter requested (e.g. provider = "serpapi")
    if (requestedProvider !== "auto") {
      const resolved = this.getProvider(requestedProvider);
      if (!resolved) {
        Logger.error("[ImageSearch]", `[${reqId}] Image search failed: Unknown provider '${requestedProvider}'`);
        throw new ProviderError(`Unknown or unregistered image provider: '${options.provider}'`);
      }

      Logger.info(
        "[ImageSearch]",
        `[${reqId}] Provider Selection -> Requested: '${requestedProvider}' | Configured Default: '${configuredDefault}' | Mode: Explicit Provider | Selected: image.${requestedProvider}`
      );

      try {
        return await this.executeWithProvider(resolved, query.trim(), options, reqId, workingDir, startTime);
      } catch (err: unknown) {
        const errMsg = err instanceof Error ? err.message : String(err);
        Logger.error(
          "[ImageSearch]",
          `[${reqId}] Explicit image provider 'image.${requestedProvider}' failed: ${errMsg}. Fallback disabled in Explicit Provider Mode.`
        );
        throw err;
      }
    }

    // 2. Explicit provider mode: Configured default provider from Settings (e.g. Default Image Provider = "serpapi")
    if (configuredDefault !== "auto") {
      const resolved = this.getProvider(configuredDefault);
      if (!resolved) {
        Logger.error("[ImageSearch]", `[${reqId}] Image search failed: Configured default provider '${configuredDefault}' is unknown or unregistered.`);
        throw new ProviderError(`Configured default image provider '${configuredDefault}' is unknown or unregistered.`);
      }

      Logger.info(
        "[ImageSearch]",
        `[${reqId}] Provider Selection -> Requested: 'auto' | Configured Default: '${configuredDefault}' | Mode: Explicit Default Provider | Selected: image.${configuredDefault}`
      );

      try {
        return await this.executeWithProvider(resolved, query.trim(), options, reqId, workingDir, startTime);
      } catch (err: unknown) {
        const errMsg = err instanceof Error ? err.message : String(err);
        Logger.error(
          "[ImageSearch]",
          `[${reqId}] Configured default image provider 'image.${configuredDefault}' failed: ${errMsg}. Fallback disabled in Explicit Provider Mode.`
        );
        throw err;
      }
    }

    // 3. Auto Provider Mode: Both requested and default are "auto". Iterate priority list with fallback.
    return this.executeFallback(query.trim(), options, reqId, requestedProvider, configuredDefault, workingDir, startTime);
  }

  /**
   * Helper method to execute search using a single target image provider.
   */
  private async executeWithProvider(
    targetProvider: BaseImageProvider,
    query: string,
    options: SearchOptions,
    reqId: string,
    workingDir: string,
    startTime: number
  ): Promise<LocalImage[]> {
    const rawResults: ImageSearchResult[] = await targetProvider.searchImages(query, options);

    if (!rawResults || rawResults.length === 0) {
      const durationMs = Date.now() - startTime;
      Logger.info(
        "[ImageSearch]",
        `[${reqId}] Image search completed. Provider: image.${targetProvider.providerName} | Duration: ${durationMs} ms | Results: 0`
      );
      return [];
    }

    const processed = await this.downloader.processResults(
      rawResults,
      targetProvider.providerName,
      workingDir
    );

    const durationMs = Date.now() - startTime;
    Logger.info(
      "[ImageSearch]",
      `[${reqId}] Image search completed. Provider: image.${targetProvider.providerName} | Duration: ${durationMs} ms | Results: ${processed.length}`
    );
    return processed;
  }

  /**
   * Iterate through registered image providers in priority order until one succeeds or all fail.
   */
  private async executeFallback(
    query: string,
    options: SearchOptions,
    reqId: string,
    requestedProvider: string,
    configuredDefault: string,
    workingDir: string,
    startTime: number
  ): Promise<LocalImage[]> {
    const priorityNames = defaultConfigurationService.getImageProviderPriority();
    const priorityIds = priorityNames
      .map((name) => ImageProviderRegistry.getSpec(name)?.id)
      .filter((id) => id !== undefined);
    Logger.info(
      "[ImageSearch]",
      `[${reqId}] Mode: Auto Provider Fallback Chain | Priority IDs: [${priorityIds.join(",")}] | Resolved Order: [${priorityNames.join(", ")}]`
    );
    const attemptedErrors: Record<string, string> = {};

    const orderedProviders: BaseImageProvider[] = [];
    for (const name of priorityNames) {
      const p = this.getProvider(name);
      if (p && !orderedProviders.includes(p)) {
        orderedProviders.push(p);
      }
    }

    if (orderedProviders.length === 0) {
      const noValMsg = "Auto (Priority Order) cannot run because the configured Provider Priority Order contains no valid providers. Update the Provider Priority Order or select a specific provider.";
      Logger.error("[ImageSearch]", `[${reqId}] ${noValMsg}`);
      throw new SearchFailedError(noValMsg, {});
    }

    let lastFailedProvider: string | null = null;
    for (const p of orderedProviders) {
      const strategy = lastFailedProvider
        ? `Fallback (after image.${lastFailedProvider} failed)`
        : "Auto Fallback Chain";
      Logger.info(
        "[ImageSearch]",
        `[${reqId}] Provider Selection -> Requested: '${requestedProvider}' | Configured Default: '${configuredDefault}' | Strategy: ${strategy} | Selected: image.${p.providerName}`
      );

      try {
        return await this.executeWithProvider(p, query, options, reqId, workingDir, startTime);
      } catch (err: unknown) {
        const errMsg = err instanceof Error ? err.message : String(err);
        attemptedErrors[p.providerName] = errMsg;
        lastFailedProvider = p.providerName;
        Logger.warn(
          "[ImageSearch]",
          `[${reqId}] Image provider 'image.${p.providerName}' exhausted/failed: ${errMsg}. Moving to next provider in configured priority order.`
        );
      }
    }

    const errDetails = Object.entries(attemptedErrors)
      .map(([p, msg]) => `${p}: ${msg}`)
      .join("; ");
    Logger.error(
      "[ImageSearch]",
      `[${reqId}] Image search failed across all providers (${orderedProviders.length} attempted). Details: ${errDetails}`
    );
    throw new SearchFailedError(
      `All image search providers failed. Errors: ${errDetails}`,
      attemptedErrors
    );
  }
}