import express, { type Request, type Response } from 'express';

import { providerAuthService } from '@/modules/providers/services/provider-auth.service.js';
import { providerMcpService } from '@/modules/providers/services/mcp.service.js';
import type { LLMProvider, McpScope, McpTransport, UpsertProviderMcpServerInput } from '@/shared/types.js';
import { AppError, asyncHandler, createApiSuccessResponse } from '@/shared/utils.js';

const router = express.Router();

const readPathParam = (value: unknown, name: string): string => {
  if (typeof value === 'string') {
    return value;
  }

  if (Array.isArray(value) && typeof value[0] === 'string') {
    return value[0];
  }

  throw new AppError(`${name} path parameter is invalid.`, {
    code: 'INVALID_PATH_PARAMETER',
    statusCode: 400,
  });
};

const normalizeProviderParam = (value: unknown): string =>
  readPathParam(value, 'provider').trim().toLowerCase();

const readOptionalQueryString = (value: unknown): string | undefined => {
  if (typeof value !== 'string') {
    return undefined;
  }

  const normalized = value.trim();
  return normalized.length > 0 ? normalized : undefined;
};

const parseMcpScope = (value: unknown): McpScope | undefined => {
  if (value === undefined) {
    return undefined;
  }

  const normalized = readOptionalQueryString(value);
  if (!normalized) {
    return undefined;
  }

  if (normalized === 'user' || normalized === 'local' || normalized === 'project') {
    return normalized;
  }

  throw new AppError(`Unsupported MCP scope "${normalized}".`, {
    code: 'INVALID_MCP_SCOPE',
    statusCode: 400,
  });
};

const parseMcpTransport = (value: unknown): McpTransport => {
  const normalized = readOptionalQueryString(value);
  if (!normalized) {
    throw new AppError('transport is required.', {
      code: 'MCP_TRANSPORT_REQUIRED',
      statusCode: 400,
    });
  }

  if (normalized === 'stdio' || normalized === 'http' || normalized === 'sse') {
    return normalized;
  }

  throw new AppError(`Unsupported MCP transport "${normalized}".`, {
    code: 'INVALID_MCP_TRANSPORT',
    statusCode: 400,
  });
};

const parseMcpUpsertPayload = (payload: unknown): UpsertProviderMcpServerInput => {
  if (!payload || typeof payload !== 'object') {
    throw new AppError('Request body must be an object.', {
      code: 'INVALID_REQUEST_BODY',
      statusCode: 400,
    });
  }

  const body = payload as Record<string, unknown>;
  const name = readOptionalQueryString(body.name);
  if (!name) {
    throw new AppError('name is required.', {
      code: 'MCP_NAME_REQUIRED',
      statusCode: 400,
    });
  }

  const transport = parseMcpTransport(body.transport);
  const scope = parseMcpScope(body.scope);
  const workspacePath = readOptionalQueryString(body.workspacePath);

  return {
    name,
    transport,
    scope,
    workspacePath,
    command: readOptionalQueryString(body.command),
    args: Array.isArray(body.args) ? body.args.filter((entry): entry is string => typeof entry === 'string') : undefined,
    env: typeof body.env === 'object' && body.env !== null
      ? Object.fromEntries(
          Object.entries(body.env as Record<string, unknown>).filter(
            (entry): entry is [string, string] => typeof entry[1] === 'string',
          ),
        )
      : undefined,
    cwd: readOptionalQueryString(body.cwd),
    url: readOptionalQueryString(body.url),
    headers: typeof body.headers === 'object' && body.headers !== null
      ? Object.fromEntries(
          Object.entries(body.headers as Record<string, unknown>).filter(
            (entry): entry is [string, string] => typeof entry[1] === 'string',
          ),
        )
      : undefined,
    envVars: Array.isArray(body.envVars)
      ? body.envVars.filter((entry): entry is string => typeof entry === 'string')
      : undefined,
    bearerTokenEnvVar: readOptionalQueryString(body.bearerTokenEnvVar),
    envHttpHeaders: typeof body.envHttpHeaders === 'object' && body.envHttpHeaders !== null
      ? Object.fromEntries(
          Object.entries(body.envHttpHeaders as Record<string, unknown>).filter(
            (entry): entry is [string, string] => typeof entry[1] === 'string',
          ),
        )
      : undefined,
  };
};

const parseProvider = (value: unknown): LLMProvider => {
  const normalized = normalizeProviderParam(value);
  if (normalized === 'claude' || normalized === 'codex' || normalized === 'cursor' || normalized === 'gemini') {
    return normalized;
  }

  throw new AppError(`Unsupported provider "${normalized}".`, {
    code: 'UNSUPPORTED_PROVIDER',
    statusCode: 400,
  });
};

router.get(
  '/:provider/auth/status',
  asyncHandler(async (req: Request, res: Response) => {
    const provider = parseProvider(req.params.provider);
    const status = await providerAuthService.getProviderAuthStatus(provider);
    res.json(status);
  }),
);

router.get(
  '/:provider/mcp/servers',
  asyncHandler(async (req: Request, res: Response) => {
    const provider = parseProvider(req.params.provider);
    const workspacePath = readOptionalQueryString(req.query.workspacePath);
    const scope = parseMcpScope(req.query.scope);

    if (scope) {
      const servers = await providerMcpService.listProviderMcpServersForScope(provider, scope, { workspacePath });
      res.json(createApiSuccessResponse({ provider, scope, servers }));
      return;
    }

    const groupedServers = await providerMcpService.listProviderMcpServers(provider, { workspacePath });
    res.json(createApiSuccessResponse({ provider, scopes: groupedServers }));
  }),
);

router.post(
  '/:provider/mcp/servers',
  asyncHandler(async (req: Request, res: Response) => {
    const provider = parseProvider(req.params.provider);
    const payload = parseMcpUpsertPayload(req.body);
    const server = await providerMcpService.upsertProviderMcpServer(provider, payload);
    res.status(201).json(createApiSuccessResponse({ server }));
  }),
);

router.put(
  '/:provider/mcp/servers/:name',
  asyncHandler(async (req: Request, res: Response) => {
    const provider = parseProvider(req.params.provider);
    const payload = parseMcpUpsertPayload({
      ...((req.body && typeof req.body === 'object') ? req.body as Record<string, unknown> : {}),
      name: readPathParam(req.params.name, 'name'),
    });
    const server = await providerMcpService.upsertProviderMcpServer(provider, payload);
    res.json(createApiSuccessResponse({ server }));
  }),
);

router.delete(
  '/:provider/mcp/servers/:name',
  asyncHandler(async (req: Request, res: Response) => {
    const provider = parseProvider(req.params.provider);
    const scope = parseMcpScope(req.query.scope);
    const workspacePath = readOptionalQueryString(req.query.workspacePath);
    const result = await providerMcpService.removeProviderMcpServer(provider, {
      name: readPathParam(req.params.name, 'name'),
      scope,
      workspacePath,
    });
    res.json(createApiSuccessResponse(result));
  }),
);

router.post(
  '/:provider/mcp/servers/:name/run',
  asyncHandler(async (req: Request, res: Response) => {
    const provider = parseProvider(req.params.provider);
    const body = (req.body as Record<string, unknown> | undefined) ?? {};
    const scope = parseMcpScope(body.scope ?? req.query.scope);
    const workspacePath = readOptionalQueryString(body.workspacePath ?? req.query.workspacePath);
    const result = await providerMcpService.runProviderMcpServer(provider, {
      name: readPathParam(req.params.name, 'name'),
      scope,
      workspacePath,
    });
    res.json(createApiSuccessResponse(result));
  }),
);

router.post(
  '/mcp/servers/global',
  asyncHandler(async (req: Request, res: Response) => {
    const payload = parseMcpUpsertPayload(req.body);
    if (payload.scope === 'local') {
      throw new AppError('Global MCP add supports only "user" or "project" scopes.', {
        code: 'INVALID_GLOBAL_MCP_SCOPE',
        statusCode: 400,
      });
    }

    const results = await providerMcpService.addMcpServerToAllProviders({
      ...payload,
      scope: payload.scope === 'user' ? 'user' : 'project',
    });
    res.status(201).json(createApiSuccessResponse({ results }));
  }),
);

export default router;