import { Config } from "../config/Config";
import { HTTPResponse } from "../http/HTTPClient";
import { KeyAuthOrQuotaError, NoAPIKeysError, ProviderError } from "../models/errors";
import { ProviderCapability } from "../types/provider";
import { SearchOptions } from "../types/search";
import { InternalProviderResult } from "./types/InternalProviderResult";
import { KeyManager } from "../utils/KeyManager";
import { Logger } from "../utils/Logger";
import { ISyncableProviderInstance } from "./ISyncableProviderInstance";
import { defaultProviderInstanceRegistry } from "./ProviderInstanceRegistry";

export interface BaseProviderOptions {
  providerName: string;
  displayName?: string;
  capabilities?: ProviderCapability[];
  keys?: string[];
  keyManager?: KeyManager;
  cooldownHours?: number;
}

/**
 * Abstract base class for all search providers.
 * Manages provider identity, capabilities, enabled state, API key rotation via KeyManager, and response parsing.
 * Mapped from Python `providers/base_provider.py` BaseProvider.
 */
export abstract class BaseProvider implements ISyncableProviderInstance {
  public readonly category: string = "web";
  protected readonly _providerName: string;
  protected readonly _displayName: string;
  protected readonly _capabilities: Set<ProviderCapability>;
  protected readonly _keyManager: KeyManager;
  protected _enabled: boolean = true;
  protected _rotationStatusCodes: number[] = [401, 403];

  constructor(
    providerNameOrOptions: string | BaseProviderOptions,
    displayName?: string,
    capabilities: ProviderCapability[] = ["web"]
  ) {
    if (typeof providerNameOrOptions === "string") {
      const pName = providerNameOrOptions;
      if (!pName || !pName.trim()) {
        throw new Error("Provider name cannot be empty.");
      }
      this._providerName = pName.toLowerCase().trim();
      this._displayName = displayName ?? pName;
      this._capabilities = new Set(capabilities);
      this._keyManager = new KeyManager({ providerName: this._providerName });
    } else {
      const options = providerNameOrOptions;
      if (!options.providerName || !options.providerName.trim()) {
        throw new Error("Provider name cannot be empty.");
      }
      this._providerName = options.providerName.toLowerCase().trim();
      this._displayName = options.displayName ?? options.providerName;
      this._capabilities = new Set(options.capabilities ?? ["web"]);
      this._keyManager =
        options.keyManager ??
        new KeyManager({
          providerName: this._providerName,
          keys: options.keys,
          defaultCooldownHours: options.cooldownHours ?? 24.0,
        });
    }

    // Auto-register this provider instance with global ProviderInstanceRegistry
    defaultProviderInstanceRegistry.register(this);
  }

  public get configIdentity(): string {
    return `${this.category}.${this._providerName}`;
  }

  public get providerName(): string {
    return this._providerName;
  }

  public get displayName(): string {
    return this._displayName;
  }

  public get capabilities(): ProviderCapability[] {
    return Array.from(this._capabilities);
  }

  public get rotationStatusCodes(): number[] {
    return this._rotationStatusCodes;
  }

  public isEnabled(): boolean {
    return this._enabled;
  }

  public enable(): void {
    this._enabled = true;
  }

  public disable(): void {
    this._enabled = false;
  }

  public hasCapability(capability: ProviderCapability): boolean {
    return this._capabilities.has(capability);
  }

  public hasKeys(): boolean {
    return this._keyManager.hasKeys();
  }

  public setKeys(keys: string[]): void {
    this._keyManager.setKeys(keys);
  }

  public currentKey(): string {
    return this._keyManager.currentKey();
  }

  public nextKey(): string {
    return this._keyManager.nextKey();
  }

  public validate(): boolean {
    return Boolean(
      this._providerName &&
        this._providerName.trim().length > 0
    );
  }

  protected _lastHttpResponseBytes: number = 0;
  protected _lastRawResultsCount: number = 0;

  public get lastHttpResponseBytes(): number {
    return this._lastHttpResponseBytes;
  }

  public get lastRawResultsCount(): number {
    return this._lastRawResultsCount;
  }

  public setLastHttpResponseBytes(bytes: number): void {
    this._lastHttpResponseBytes = bytes;
  }

  public setLastRawResultsCount(count: number): void {
    this._lastRawResultsCount = count;
  }

  /**
   * Validate HTTP response status and decode JSON payload.
   * Mapped from Python `BaseProvider._parse_json_response()`.
   */
  protected parseJsonResponse<T = Record<string, unknown>>(response: HTTPResponse): T {
    this._lastHttpResponseBytes = response.buffer?.length ?? Buffer.byteLength(response.text ?? "", "utf-8");

    const providerLabel =
      this._providerName.charAt(0).toUpperCase() + this._providerName.slice(1);

    if (response.statusCode !== 200) {
      if (this._rotationStatusCodes.includes(response.statusCode)) {
        throw new KeyAuthOrQuotaError(
          `${providerLabel} search failed with status code ${response.statusCode}: ${response.text}`,
          response.statusCode
        );
      }
      throw new ProviderError(
        `${providerLabel} search failed with status code ${response.statusCode}: ${response.text}`
      );
    }

    const data = response.data;
    if (!data || typeof data !== "object") {
      throw new ProviderError(
        `Invalid response payload from ${providerLabel} API: expected JSON object`
      );
    }

    return data as T;
  }

  /**
   * Defensively slice result array to guarantee returning at most maxResults items.
   */
  protected enforceResultLimit<T>(results: T[], maxResults?: number): T[] {
    if (typeof maxResults === "number" && maxResults >= 0) {
      return results.slice(0, maxResults);
    }
    return results;
  }

  /**
   * Execute request function with automatic API key rotation on auth/quota errors.
   * Mapped from Python `BaseProvider._execute_with_key_rotation()`.
   */
  protected async executeWithKeyRotation<T>(
    requestFn: (apiKey: string) => Promise<T>
  ): Promise<T> {
    const totalKeys = this._keyManager.keyCount();
    if (totalKeys === 0) {
      throw new NoAPIKeysError(
        `No API keys configured for provider '${this._providerName}'`
      );
    }

    let lastKeyError: KeyAuthOrQuotaError | null = null;
    let lastGeneralError: Error | null = null;

    for (let attempt = 0; attempt < totalKeys; attempt++) {
      const activeKey = this.currentKey();
      try {
        const result = await requestFn(activeKey);
        this._keyManager.markKeySuccess(activeKey);
        return result;
      } catch (err: unknown) {
        if (err instanceof KeyAuthOrQuotaError) {
          lastKeyError = err;
          if (err.statusCode === 401) {
            Logger.warn(
              "[Provider]",
              `${this.configIdentity}: Key #${attempt + 1} received status 401 (Unauthorized). Disabling key permanently...`
            );
            this._keyManager.markKeyInvalid(activeKey);
          } else {
            Logger.warn(
              "[Provider]",
              `${this.configIdentity}: Key #${attempt + 1} received status ${err.statusCode} (Quota/Rate Limit). Disabling key (cooldown active)...`
            );
            this._keyManager.markKeyExhausted(activeKey, err.retryAfter);
          }
          if (attempt < totalKeys - 1) {
            this.nextKey();
          }
        } else {
          lastGeneralError = err instanceof Error ? err : new Error(String(err));
          Logger.warn(
            "[Provider]",
            `${this.configIdentity}: Key #${attempt + 1} request failed (${lastGeneralError.message}). Trying next available key...`
          );
          if (attempt < totalKeys - 1) {
            this.nextKey();
          } else {
            throw lastGeneralError;
          }
        }
      }
    }

    if (lastGeneralError) {
      throw lastGeneralError;
    }

    const lastStatus = lastKeyError ? lastKeyError.statusCode : "Unknown";
    const msg = `All ${totalKeys} configured API keys for provider '${this._providerName}' failed authentication or quota limits. Last status: ${lastStatus}`;
    throw new ProviderError(msg);
  }

  public abstract search(query: string, options?: SearchOptions): Promise<InternalProviderResult[]>;
}

import { Config } from "../config/Config";
import { HTTPResponse } from "../http/HTTPClient";
import { KeyAuthOrQuotaError, NoAPIKeysError, ProviderError } from "../models/errors";
import { ProviderCapability } from "../types/provider";
import { SearchOptions } from "../types/search";
import { InternalProviderResult } from "./types/InternalProviderResult";
import { KeyManager } from "../utils/KeyManager";
import { Logger } from "../utils/Logger";
import { ISyncableProviderInstance } from "./ISyncableProviderInstance";
import { defaultProviderInstanceRegistry } from "./ProviderInstanceRegistry";

export interface BaseProviderOptions {
  providerName: string;
  displayName?: string;
  capabilities?: ProviderCapability[];
  keys?: string[];
  keyManager?: KeyManager;
  cooldownHours?: number;
}

/**
 * Abstract base class for all search providers.
 * Manages provider identity, capabilities, enabled state, API key rotation via KeyManager, and response parsing.
 * Mapped from Python `providers/base_provider.py` BaseProvider.
 */
export abstract class BaseProvider implements ISyncableProviderInstance {
  public readonly category: string = "web";
  protected readonly _providerName: string;
  protected readonly _displayName: string;
  protected readonly _capabilities: Set<ProviderCapability>;
  protected readonly _keyManager: KeyManager;
  protected _enabled: boolean = true;
  protected _rotationStatusCodes: number[] = [401, 403];

  constructor(
    providerNameOrOptions: string | BaseProviderOptions,
    displayName?: string,
    capabilities: ProviderCapability[] = ["web"]
  ) {
    if (typeof providerNameOrOptions === "string") {
      const pName = providerNameOrOptions;
      if (!pName || !pName.trim()) {
        throw new Error("Provider name cannot be empty.");
      }
      this._providerName = pName.toLowerCase().trim();
      this._displayName = displayName ?? pName;
      this._capabilities = new Set(capabilities);
      this._keyManager = new KeyManager({ providerName: this._providerName });
    } else {
      const options = providerNameOrOptions;
      if (!options.providerName || !options.providerName.trim()) {
        throw new Error("Provider name cannot be empty.");
      }
      this._providerName = options.providerName.toLowerCase().trim();
      this._displayName = options.displayName ?? options.providerName;
      this._capabilities = new Set(options.capabilities ?? ["web"]);
      this._keyManager =
        options.keyManager ??
        new KeyManager({
          providerName: this._providerName,
          keys: options.keys,
          defaultCooldownHours: options.cooldownHours ?? 24.0,
        });
    }

    // Auto-register this provider instance with global ProviderInstanceRegistry
    defaultProviderInstanceRegistry.register(this);
  }

  public get configIdentity(): string {
    return `${this.category}.${this._providerName}`;
  }

  public get providerName(): string {
    return this._providerName;
  }

  public get displayName(): string {
    return this._displayName;
  }

  public get capabilities(): ProviderCapability[] {
    return Array.from(this._capabilities);
  }

  public get rotationStatusCodes(): number[] {
    return this._rotationStatusCodes;
  }

  public isEnabled(): boolean {
    return this._enabled;
  }

  public enable(): void {
    this._enabled = true;
  }

  public disable(): void {
    this._enabled = false;
  }

  public hasCapability(capability: ProviderCapability): boolean {
    return this._capabilities.has(capability);
  }

  public hasKeys(): boolean {
    return this._keyManager.hasKeys();
  }

  public setKeys(keys: string[]): void {
    this._keyManager.setKeys(keys);
  }

  public currentKey(): string {
    return this._keyManager.currentKey();
  }

  public nextKey(): string {
    return this._keyManager.nextKey();
  }

  public validate(): boolean {
    return Boolean(
      this._providerName &&
        this._providerName.trim().length > 0
    );
  }

  protected _lastHttpResponseBytes: number = 0;
  protected _lastRawResultsCount: number = 0;

  public get lastHttpResponseBytes(): number {
    return this._lastHttpResponseBytes;
  }

  public get lastRawResultsCount(): number {
    return this._lastRawResultsCount;
  }

  public setLastHttpResponseBytes(bytes: number): void {
    this._lastHttpResponseBytes = bytes;
  }

  public setLastRawResultsCount(count: number): void {
    this._lastRawResultsCount = count;
  }

  /**
   * Validate HTTP response status and decode JSON payload.
   * Mapped from Python `BaseProvider._parse_json_response()`.
   */
  protected parseJsonResponse<T = Record<string, unknown>>(response: HTTPResponse): T {
    this._lastHttpResponseBytes = response.buffer?.length ?? Buffer.byteLength(response.text ?? "", "utf-8");

    const providerLabel =
      this._providerName.charAt(0).toUpperCase() + this._providerName.slice(1);

    if (response.statusCode !== 200) {
      if (this._rotationStatusCodes.includes(response.statusCode)) {
        throw new KeyAuthOrQuotaError(
          `${providerLabel} search failed with status code ${response.statusCode}: ${response.text}`,
          response.statusCode
        );
      }
      throw new ProviderError(
        `${providerLabel} search failed with status code ${response.statusCode}: ${response.text}`
      );
    }

    const data = response.data;
    if (!data || typeof data !== "object") {
      throw new ProviderError(
        `Invalid response payload from ${providerLabel} API: expected JSON object`
      );
    }

    return data as T;
  }

  /**
   * Defensively slice result array to guarantee returning at most maxResults items.
   */
  protected enforceResultLimit<T>(results: T[], maxResults?: number): T[] {
    if (typeof maxResults === "number" && maxResults >= 0) {
      return results.slice(0, maxResults);
    }
    return results;
  }

  /**
   * Execute request function with automatic API key rotation on auth/quota errors.
   * Mapped from Python `BaseProvider._execute_with_key_rotation()`.
   */
  protected async executeWithKeyRotation<T>(
    requestFn: (apiKey: string) => Promise<T>
  ): Promise<T> {
    const totalKeys = this._keyManager.keyCount();
    if (totalKeys === 0) {
      throw new NoAPIKeysError(
        `No API keys configured for provider '${this._providerName}'`
      );
    }

    let lastKeyError: KeyAuthOrQuotaError | null = null;
    let lastGeneralError: Error | null = null;

    for (let attempt = 0; attempt < totalKeys; attempt++) {
      const activeKey = this.currentKey();
      try {
        const result = await requestFn(activeKey);
        this._keyManager.markKeySuccess(activeKey);
        return result;
      } catch (err: unknown) {
        if (err instanceof KeyAuthOrQuotaError) {
          lastKeyError = err;
          if (err.statusCode === 401) {
            Logger.warn(
              "[Provider]",
              `${this.configIdentity}: Key #${attempt + 1} received status 401 (Unauthorized). Disabling key permanently...`
            );
            this._keyManager.markKeyInvalid(activeKey);
          } else {
            Logger.warn(
              "[Provider]",
              `${this.configIdentity}: Key #${attempt + 1} received status ${err.statusCode} (Quota/Rate Limit). Disabling key (cooldown active)...`
            );
            this._keyManager.markKeyExhausted(activeKey, err.retryAfter);
          }
          if (attempt < totalKeys - 1) {
            this.nextKey();
          }
        } else {
          lastGeneralError = err instanceof Error ? err : new Error(String(err));
          Logger.warn(
            "[Provider]",
            `${this.configIdentity}: Key #${attempt + 1} request failed (${lastGeneralError.message}). Trying next available key...`
          );
          if (attempt < totalKeys - 1) {
            this.nextKey();
          } else {
            throw lastGeneralError;
          }
        }
      }
    }

    if (lastGeneralError) {
      throw lastGeneralError;
    }

    const lastStatus = lastKeyError ? lastKeyError.statusCode : "Unknown";
    const msg = `All ${totalKeys} configured API keys for provider '${this._providerName}' failed authentication or quota limits. Last status: ${lastStatus}`;
    throw new ProviderError(msg);
  }

  public abstract search(query: string, options?: SearchOptions): Promise<InternalProviderResult[]>;
}