src/shared/constants/errorCodes.ts

/**
 * Error Codes Catalog — T-22
 *
 * Centralized error code registry for consistent API error responses.
 * Each code has a category prefix, numeric ID, message, and HTTP status.
 *
 * Usage:
 *   import { ERROR_CODES, createErrorResponse } from "@/shared/constants/errorCodes";
 *   return createErrorResponse("AUTH_001", { detail: "Token expired" });
 *
 * @module shared/constants/errorCodes
 */

export interface ErrorCodeDef {
  code: string;
  message: string;
  httpStatus: number;
  category: string;
}

interface ErrorDetails {
  detail?: string;
  requestId?: string;
  retryAfter?: number;
}

export const ERROR_CODES: Record<string, ErrorCodeDef> = {
  // ── Auth ──
  AUTH_001: {
    code: "AUTH_001",
    message: "Authentication required",
    httpStatus: 401,
    category: "AUTH",
  },
  AUTH_002: { code: "AUTH_002", message: "Invalid API key", httpStatus: 401, category: "AUTH" },
  AUTH_003: { code: "AUTH_003", message: "API key expired", httpStatus: 401, category: "AUTH" },
  AUTH_004: {
    code: "AUTH_004",
    message: "Insufficient permissions",
    httpStatus: 403,
    category: "AUTH",
  },
  AUTH_005: { code: "AUTH_005", message: "Account locked", httpStatus: 423, category: "AUTH" },
  AUTH_006: {
    code: "AUTH_006",
    message: "No credentials for provider",
    httpStatus: 400,
    category: "AUTH",
  },

  // ── Proxy ──
  PROXY_001: {
    code: "PROXY_001",
    message: "Proxy connection failed",
    httpStatus: 502,
    category: "PROXY",
  },
  PROXY_002: { code: "PROXY_002", message: "Proxy timeout", httpStatus: 504, category: "PROXY" },
  PROXY_003: {
    code: "PROXY_003",
    message: "All proxies exhausted",
    httpStatus: 503,
    category: "PROXY",
  },

  // ── Rate Limiting ──
  RATE_001: {
    code: "RATE_001",
    message: "Rate limit exceeded",
    httpStatus: 429,
    category: "RATE_LIMIT",
  },
  RATE_002: {
    code: "RATE_002",
    message: "Daily budget exceeded",
    httpStatus: 429,
    category: "RATE_LIMIT",
  },
  RATE_003: {
    code: "RATE_003",
    message: "All accounts rate-limited",
    httpStatus: 503,
    category: "RATE_LIMIT",
  },

  // ── Model / Routing ──
  MODEL_001: { code: "MODEL_001", message: "Model not found", httpStatus: 404, category: "MODEL" },
  MODEL_002: {
    code: "MODEL_002",
    message: "Ambiguous model identifier",
    httpStatus: 400,
    category: "MODEL",
  },
  MODEL_003: {
    code: "MODEL_003",
    message: "Model temporarily unavailable",
    httpStatus: 503,
    category: "MODEL",
  },

  // ── Provider ──
  PROVIDER_001: {
    code: "PROVIDER_001",
    message: "Provider error",
    httpStatus: 502,
    category: "PROVIDER",
  },
  PROVIDER_002: {
    code: "PROVIDER_002",
    message: "Provider timeout",
    httpStatus: 504,
    category: "PROVIDER",
  },
  PROVIDER_003: {
    code: "PROVIDER_003",
    message: "Provider not configured",
    httpStatus: 400,
    category: "PROVIDER",
  },

  // ── Validation ──
  VALID_001: {
    code: "VALID_001",
    message: "Invalid request body",
    httpStatus: 400,
    category: "VALIDATION",
  },
  VALID_002: {
    code: "VALID_002",
    message: "Missing required field",
    httpStatus: 400,
    category: "VALIDATION",
  },
  VALID_003: {
    code: "VALID_003",
    message: "Input sanitization blocked",
    httpStatus: 400,
    category: "VALIDATION",
  },

  // ── Internal ──
  INTERNAL_001: {
    code: "INTERNAL_001",
    message: "Internal server error",
    httpStatus: 500,
    category: "INTERNAL",
  },
  INTERNAL_002: {
    code: "INTERNAL_002",
    message: "Database error",
    httpStatus: 500,
    category: "INTERNAL",
  },
  INTERNAL_003: {
    code: "INTERNAL_003",
    message: "Circuit breaker open",
    httpStatus: 503,
    category: "INTERNAL",
  },
};

export function createErrorResponse(code: string, details: ErrorDetails = {}) {
  const def = ERROR_CODES[code];
  if (!def) {
    return {
      error: {
        code: "INTERNAL_001",
        message: `Unknown error code: ${code}`,
        category: "INTERNAL",
      },
      status: 500,
    };
  }

  const response: any = {
    error: {
      code: def.code,
      message: def.message,
      category: def.category,
      ...(details.detail ? { detail: details.detail } : {}),
      ...(details.requestId ? { requestId: details.requestId } : {}),
    },
    status: def.httpStatus,
  };

  if (details.retryAfter) {
    response.retryAfter = details.retryAfter;
  }

  return response;
}

export function getErrorsByCategory(category: string): ErrorCodeDef[] {
  return Object.values(ERROR_CODES).filter((e) => e.category === category);
}