import type {
  GenerateRequest,
  GenerateResponse,
  JobResult,
  ApiError,
  PromptDefaults,
  ModifyRequest,
  UsageMetricsResponse,
  PromptLocale
} from '../types/api';
import { loadSettings } from './settings';
import { localizeApiMessage, translate } from '../i18n';

const API_BASE = '/api';

function getAuthHeaders(contentType = 'application/json'): HeadersInit {
  const headers: HeadersInit = {};
  if (contentType) {
    headers['Content-Type'] = contentType;
  }

  const apiKey = localStorage.getItem('manimcat_api_key');
  if (apiKey) {
    headers['Authorization'] = `Bearer ${apiKey}`;
  }

  return headers;
}

export async function modifyAnimation(request: ModifyRequest, signal?: AbortSignal): Promise<GenerateResponse> {
  const videoConfig = request.videoConfig || loadSettings().video;
  const payload = { ...request, videoConfig };

  const response = await fetch(`${API_BASE}/modify`, {
    method: 'POST',
    headers: getAuthHeaders(),
    body: JSON.stringify(payload),
    signal,
  });

  if (!response.ok) {
    const error: ApiError = await response.json();
    throw new Error(error.error ? localizeApiMessage(error.error) : translate('api.modifyFailed'));
  }

  return response.json();
}

interface UploadReferenceImageResponse {
  success: boolean;
  url: string;
  relativeUrl: string;
  mimeType: string;
  size: number;
}

export async function uploadReferenceImage(file: File, signal?: AbortSignal): Promise<UploadReferenceImageResponse> {
  const response = await fetch(`${API_BASE}/reference-images`, {
    method: 'POST',
    headers: getAuthHeaders(file.type || 'application/octet-stream'),
    body: file,
    signal,
  });

  if (!response.ok) {
    let message = translate('api.uploadFailed');
    try {
      const error: ApiError = await response.json();
      message = error.error ? localizeApiMessage(error.error) : message;
    } catch {
      // ignore json parse errors and keep default message
    }
    throw new Error(message);
  }

  return response.json();
}

export async function generateAnimation(request: GenerateRequest, signal?: AbortSignal): Promise<GenerateResponse> {
  const videoConfig = request.videoConfig || loadSettings().video;
  const payload = { ...request, videoConfig };

  const response = await fetch(`${API_BASE}/generate`, {
    method: 'POST',
    headers: getAuthHeaders(),
    body: JSON.stringify(payload),
    signal,
  });

  if (!response.ok) {
    const error: ApiError = await response.json();
    throw new Error(error.error ? localizeApiMessage(error.error) : translate('api.generateFailed'));
  }

  return response.json();
}

export async function getPromptDefaults(locale?: PromptLocale, signal?: AbortSignal): Promise<PromptDefaults> {
  const query = locale ? `?locale=${encodeURIComponent(locale)}` : '';
  const response = await fetch(`${API_BASE}/prompts/defaults${query}`, {
    headers: getAuthHeaders(),
    signal,
  });

  if (!response.ok) {
    const error: ApiError = await response.json();
    throw new Error(error.error || 'Failed to load prompt defaults');
  }

  return response.json();
}

export async function getJobStatus(jobId: string, signal?: AbortSignal): Promise<JobResult> {
  const response = await fetch(`${API_BASE}/jobs/${jobId}`, {
    headers: getAuthHeaders(),
    signal,
  });

  if (!response.ok) {
    const error: ApiError = await response.json();
    throw new Error(error.error ? localizeApiMessage(error.error) : translate('api.jobStatusFailed'));
  }

  return response.json();
}

export async function cancelJob(jobId: string): Promise<void> {
  const response = await fetch(`${API_BASE}/jobs/${jobId}/cancel`, {
    method: 'POST',
    headers: getAuthHeaders(),
  });

  if (!response.ok) {
    const error: ApiError = await response.json();
    throw new Error(error.error ? localizeApiMessage(error.error) : translate('api.cancelFailed'));
  }
}

export async function getUsageMetrics(days = 7, signal?: AbortSignal): Promise<UsageMetricsResponse> {
  const response = await fetch(`${API_BASE}/metrics/usage?days=${days}`, {
    headers: getAuthHeaders(),
    signal,
  });

  if (!response.ok) {
    const error: ApiError = await response.json();
    throw new Error(error.error ? localizeApiMessage(error.error) : translate('api.usageFailed'));
  }

  return response.json();
}