export interface PrioritySlotOption {
  id: number;
  value: string;
  displayName: string;
}

/**
 * Reusable PrioritySlotEditor component responsible for managing provider priority orders.
 * Supports mapping numeric provider IDs (e.g. 1, 2, 3) or canonical names (e.g. exa, tavily).
 * Operates purely on `string[]` input and output.
 * Guarantees zero duplicates, zero missing providers, and implements auto-swap de-duplication.
 */
export class PrioritySlotEditor {
  private availableProviders: PrioritySlotOption[];

  constructor(availableProviders: PrioritySlotOption[]) {
    this.availableProviders = availableProviders;
  }

  /**
   * Return array of available provider options.
   */
  public getAvailableProviders(): PrioritySlotOption[] {
    return [...this.availableProviders];
  }

  /**
   * Normalize any raw array or string (numeric IDs like "1,2,3" or names like "exa,tavily")
   * into a valid ordered string[] containing every available provider name exactly once.
   *
   * @param rawOrder String array or comma-separated string representation.
   * @returns Normalized string[] array with zero duplicates.
   */
  public normalizeOrder(rawOrder?: string[] | string): string[] {
    const allValues = this.availableProviders.map((p) => p.value);

    // If completely unconfigured (undefined, null, or empty string/array), return all registered providers
    if (rawOrder === undefined || rawOrder === null) {
      return [...allValues];
    }
    if (typeof rawOrder === "string" && !rawOrder.trim()) {
      return [...allValues];
    }
    if (Array.isArray(rawOrder) && rawOrder.length === 0) {
      return [...allValues];
    }

    let parsed: string[] = [];
    if (Array.isArray(rawOrder)) {
      parsed = rawOrder.map((s) => String(s).trim().toLowerCase()).filter(Boolean);
    } else if (typeof rawOrder === "string") {
      parsed = rawOrder
        .split(",")
        .map((s) => s.trim().toLowerCase())
        .filter(Boolean);
    }

    // If parsed has no non-empty tokens after splitting (e.g., ",,"), treat as empty string (all providers)
    if (parsed.length === 0) {
      return [...allValues];
    }

    const result: string[] = [];

    for (let token of parsed) {
      token = token.trim().toLowerCase();

      // 1. Try matching by numeric provider ID (e.g., "1" -> exa)
      const numId = Number.parseInt(token, 10);
      let matchedSpec: PrioritySlotOption | undefined;
      if (!Number.isNaN(numId)) {
        matchedSpec = this.availableProviders.find((p) => p.id === numId);
      }

      // 2. Try matching by provider string name (e.g., "exa" -> exa)
      if (!matchedSpec) {
        matchedSpec = this.availableProviders.find((p) => p.value.toLowerCase() === token);
      }

      if (matchedSpec && !result.includes(matchedSpec.value)) {
        result.push(matchedSpec.value);
      }
    }

    // Return ONLY the valid user-requested providers (deduplicated).
    // Note: Do NOT automatically append missing providers.
    // If user provided non-empty input but zero tokens were valid (e.g. "99,a"), result is [].
    return result;
  }

  /**
   * Handle user changing slot at targetIndex to newValue (numeric ID or provider name).
   * If newValue is already selected in another slot (existingIndex), automatically swap the two positions.
   *
   * @param currentOrder Current ordered string[] array.
   * @param targetIndex Slot position index (0-based) being modified.
   * @param newValue Selected provider ID or name for targetIndex.
   * @returns New updated and de-duplicated string[] array.
   */
  public handleSlotChange(
    currentOrder: string[],
    targetIndex: number,
    newValue: string
  ): string[] {
    const normalized = this.normalizeOrder(currentOrder);

    // Resolve newValue to canonical provider name
    let targetName = newValue.trim().toLowerCase();
    const numId = Number.parseInt(targetName, 10);
    if (!Number.isNaN(numId)) {
      const spec = this.availableProviders.find((p) => p.id === numId);
      if (spec) targetName = spec.value;
    }

    if (targetIndex < 0 || targetIndex >= normalized.length) {
      return normalized;
    }

    const existingIndex = normalized.indexOf(targetName);

    if (existingIndex !== -1 && existingIndex !== targetIndex) {
      // Auto-swap: swap values between targetIndex and existingIndex
      const oldValue = normalized[targetIndex];
      normalized[targetIndex] = targetName;
      normalized[existingIndex] = oldValue;
    } else {
      normalized[targetIndex] = targetName;
    }

    return this.normalizeOrder(normalized);
  }
}

export interface PrioritySlotOption {
  id: number;
  value: string;
  displayName: string;
}

/**
 * Reusable PrioritySlotEditor component responsible for managing provider priority orders.
 * Supports mapping numeric provider IDs (e.g. 1, 2, 3) or canonical names (e.g. exa, tavily).
 * Operates purely on `string[]` input and output.
 * Guarantees zero duplicates, zero missing providers, and implements auto-swap de-duplication.
 */
export class PrioritySlotEditor {
  private availableProviders: PrioritySlotOption[];

  constructor(availableProviders: PrioritySlotOption[]) {
    this.availableProviders = availableProviders;
  }

  /**
   * Return array of available provider options.
   */
  public getAvailableProviders(): PrioritySlotOption[] {
    return [...this.availableProviders];
  }

  /**
   * Normalize any raw array or string (numeric IDs like "1,2,3" or names like "exa,tavily")
   * into a valid ordered string[] containing every available provider name exactly once.
   *
   * @param rawOrder String array or comma-separated string representation.
   * @returns Normalized string[] array with zero duplicates.
   */
  public normalizeOrder(rawOrder?: string[] | string): string[] {
    const allValues = this.availableProviders.map((p) => p.value);

    // If completely unconfigured (undefined, null, or empty string/array), return all registered providers
    if (rawOrder === undefined || rawOrder === null) {
      return [...allValues];
    }
    if (typeof rawOrder === "string" && !rawOrder.trim()) {
      return [...allValues];
    }
    if (Array.isArray(rawOrder) && rawOrder.length === 0) {
      return [...allValues];
    }

    let parsed: string[] = [];
    if (Array.isArray(rawOrder)) {
      parsed = rawOrder.map((s) => String(s).trim().toLowerCase()).filter(Boolean);
    } else if (typeof rawOrder === "string") {
      parsed = rawOrder
        .split(",")
        .map((s) => s.trim().toLowerCase())
        .filter(Boolean);
    }

    // If parsed has no non-empty tokens after splitting (e.g., ",,"), treat as empty string (all providers)
    if (parsed.length === 0) {
      return [...allValues];
    }

    const result: string[] = [];

    for (let token of parsed) {
      token = token.trim().toLowerCase();

      // 1. Try matching by numeric provider ID (e.g., "1" -> exa)
      const numId = Number.parseInt(token, 10);
      let matchedSpec: PrioritySlotOption | undefined;
      if (!Number.isNaN(numId)) {
        matchedSpec = this.availableProviders.find((p) => p.id === numId);
      }

      // 2. Try matching by provider string name (e.g., "exa" -> exa)
      if (!matchedSpec) {
        matchedSpec = this.availableProviders.find((p) => p.value.toLowerCase() === token);
      }

      if (matchedSpec && !result.includes(matchedSpec.value)) {
        result.push(matchedSpec.value);
      }
    }

    // Return ONLY the valid user-requested providers (deduplicated).
    // Note: Do NOT automatically append missing providers.
    // If user provided non-empty input but zero tokens were valid (e.g. "99,a"), result is [].
    return result;
  }

  /**
   * Handle user changing slot at targetIndex to newValue (numeric ID or provider name).
   * If newValue is already selected in another slot (existingIndex), automatically swap the two positions.
   *
   * @param currentOrder Current ordered string[] array.
   * @param targetIndex Slot position index (0-based) being modified.
   * @param newValue Selected provider ID or name for targetIndex.
   * @returns New updated and de-duplicated string[] array.
   */
  public handleSlotChange(
    currentOrder: string[],
    targetIndex: number,
    newValue: string
  ): string[] {
    const normalized = this.normalizeOrder(currentOrder);

    // Resolve newValue to canonical provider name
    let targetName = newValue.trim().toLowerCase();
    const numId = Number.parseInt(targetName, 10);
    if (!Number.isNaN(numId)) {
      const spec = this.availableProviders.find((p) => p.id === numId);
      if (spec) targetName = spec.value;
    }

    if (targetIndex < 0 || targetIndex >= normalized.length) {
      return normalized;
    }

    const existingIndex = normalized.indexOf(targetName);

    if (existingIndex !== -1 && existingIndex !== targetIndex) {
      // Auto-swap: swap values between targetIndex and existingIndex
      const oldValue = normalized[targetIndex];
      normalized[targetIndex] = targetName;
      normalized[existingIndex] = oldValue;
    } else {
      normalized[targetIndex] = targetName;
    }

    return this.normalizeOrder(normalized);
  }
}