import type { HostApiContext } from '../context';
import type { NormalizedHostApiRequest } from '../route-utils';
import { fail, ok, parseJsonBody } from '../route-utils';
import { syncProviderRuntimeSnapshot } from '@electron/service/provider-runtime-sync';
import {
  assignChannelToAgent,
  clearChannelBinding,
  createAgentConfig,
  deleteAgentConfig,
  listAgentsSnapshot,
  updateAgentModelConfig,
  updateAgentName,
} from '../../utils/agent-config';

function getProviderSnapshot(ctx: HostApiContext) {
  const accounts = ctx.providerApiService
    .getAccounts()
    .filter((account) => account.enabled !== false);
  const defaultAccountId = ctx.providerApiService.getDefault().accountId;
  return { accounts, defaultAccountId };
}

function formatRuntimeWarning(warnings: string[]): string | null {
  if (warnings.length === 0) return null;
  return `Runtime sync warnings: ${warnings.join('; ')}`;
}

export async function handleAgentRoutes(
  request: NormalizedHostApiRequest,
  ctx: HostApiContext,
) {
  const { pathname, method } = request;
  const { accounts, defaultAccountId } = getProviderSnapshot(ctx);

  if (pathname === '/api/agents' && method === 'GET') {
    return ok({
      success: true,
      ...listAgentsSnapshot(accounts, defaultAccountId),
    });
  }

  if (pathname === '/api/agents' && method === 'POST') {
    try {
      const body = parseJsonBody<{ name?: string; inheritWorkspace?: boolean }>(request.body);
      if (!body?.name || !String(body.name).trim()) {
        return fail(400, 'name is required');
      }

      const snapshot = createAgentConfig(body.name, { inheritWorkspace: body.inheritWorkspace }, accounts, defaultAccountId);
      const runtimeSync = syncProviderRuntimeSnapshot({ accounts, defaultAccountId, snapshot });
      ctx.gatewayManager.reloadProviders({
        topics: ['agents', 'providers', 'models'],
        reason: 'agents:created',
        warnings: runtimeSync.warnings,
      });

      return ok({
        success: true,
        warning: formatRuntimeWarning(runtimeSync.warnings),
        ...snapshot,
      });
    } catch (error) {
      return fail(500, error instanceof Error ? error.message : String(error));
    }
  }

  if (!pathname.startsWith('/api/agents/')) {
    return null;
  }

  const suffix = pathname.slice('/api/agents/'.length);
  const parts = suffix.split('/').filter(Boolean).map((part) => decodeURIComponent(part));

  if (parts.length === 0) {
    return null;
  }

  if (method === 'PUT' && parts.length === 1) {
    try {
      const body = parseJsonBody<{ name?: string }>(request.body);
      if (!body?.name || !String(body.name).trim()) {
        return fail(400, 'name is required');
      }

      const snapshot = updateAgentName(parts[0], body.name, accounts, defaultAccountId);
      const runtimeSync = syncProviderRuntimeSnapshot({ accounts, defaultAccountId, snapshot });
      ctx.gatewayManager.notifyRuntimeChanged({
        topics: ['agents'],
        reason: 'agents:renamed',
        warnings: runtimeSync.warnings,
      });

      return ok({
        success: true,
        warning: formatRuntimeWarning(runtimeSync.warnings),
        ...snapshot,
      });
    } catch (error) {
      return fail(500, error instanceof Error ? error.message : String(error));
    }
  }

  if (method === 'PUT' && parts.length === 2 && parts[1] === 'model') {
    try {
      const body = parseJsonBody<{ modelRef?: string | null; providerAccountId?: string | null }>(request.body);
      const snapshot = updateAgentModelConfig(
        parts[0],
        body?.modelRef ?? null,
        body?.providerAccountId ?? null,
        accounts,
        defaultAccountId,
      );
      const runtimeSync = syncProviderRuntimeSnapshot({ accounts, defaultAccountId, snapshot });
      ctx.gatewayManager.reloadProviders({
        topics: ['agents', 'providers', 'models'],
        reason: 'agents:model-updated',
        warnings: runtimeSync.warnings,
      });

      return ok({
        success: true,
        warning: formatRuntimeWarning(runtimeSync.warnings),
        ...snapshot,
      });
    } catch (error) {
      return fail(500, error instanceof Error ? error.message : String(error));
    }
  }

  if (method === 'PUT' && parts.length === 3 && parts[1] === 'channels') {
    try {
      const body = parseJsonBody<{ accountId?: string | null }>(request.body);
      const snapshot = assignChannelToAgent(parts[0], parts[2], body?.accountId ?? null, accounts, defaultAccountId);
      ctx.gatewayManager.notifyRuntimeChanged({
        topics: ['agents', 'channels', 'channel-targets'],
        reason: 'agents:channel-assigned',
        channelType: parts[2],
        accountId: body?.accountId ?? undefined,
      });
      return ok({
        success: true,
        ...snapshot,
      });
    } catch (error) {
      return fail(500, error instanceof Error ? error.message : String(error));
    }
  }

  if (method === 'DELETE' && parts.length === 1) {
    try {
      const snapshot = deleteAgentConfig(parts[0], accounts, defaultAccountId);
      const runtimeSync = syncProviderRuntimeSnapshot({ accounts, defaultAccountId, snapshot });
      await ctx.gatewayManager.restart({
        topics: ['agents', 'providers', 'models', 'channels', 'channel-targets'],
        reason: 'agents:deleted',
        warnings: runtimeSync.warnings,
      });

      return ok({
        success: true,
        warning: formatRuntimeWarning(runtimeSync.warnings),
        ...snapshot,
      });
    } catch (error) {
      return fail(500, error instanceof Error ? error.message : String(error));
    }
  }

  if (method === 'DELETE' && parts.length === 3 && parts[1] === 'channels') {
    try {
      const accountId = request.url.searchParams.get('accountId')?.trim() || null;
      const snapshot = clearChannelBinding(parts[2], accountId, accounts, defaultAccountId);
      ctx.gatewayManager.notifyRuntimeChanged({
        topics: ['agents', 'channels', 'channel-targets'],
        reason: 'agents:channel-cleared',
        channelType: parts[2],
        accountId: accountId ?? undefined,
      });
      return ok({
        success: true,
        ...snapshot,
      });
    } catch (error) {
      return fail(500, error instanceof Error ? error.message : String(error));
    }
  }

  return null;
}