const API_BASE = 'https://cfx9z50wj2.execute-api.ca-central-1.amazonaws.com/prod';

async function http<T>(path: string, init?: RequestInit): Promise<T> {
  const base = API_BASE ? API_BASE.replace(/\/+$/, '') : '';
  const normalizedPath = path.startsWith('/') ? path : `/${path}`;
  const url = `${base}${normalizedPath}`;

  const res = await fetch(url, {
    ...init,
    headers: {
      "Content-Type": "application/json",
      ...(init?.headers || {})
    }
  });

  if (!res.ok) {
    const text = await res.text().catch(() => "");
    throw new Error(`HTTP ${res.status} ${res.statusText}: ${text}`);
  }

  return (await res.json()) as T;
}

export type CaseStatus = {
  case: {
    case_id: string;
    status: string;
    current_step: string | null;
    created_at: string;
    updated_at: string;
  };
  steps: Array<{
    step_name: string;
    step_order: number;
    status: string;
    started_at: string | null;
    finished_at: string | null;
    error_message: string | null;
  }>;
};

export type CaseAssets = {
  caseId: string;
  apImageUrl: string;
  bucket?: string;
  key?: string;
};

export type SubmitLandmarksRequest = {
  // Backend Lambda requires caseId in body (even though it's also in the URL)
  caseId?: string;
  view: "ap";
  landmarks: Record<string, { x: number; y: number }>;
};

export type SubmitLandmarksResponse = {
  ok: boolean;
  caseId: string;
  resumedPipeline: boolean;
  values: {
    pelvis_offset_px: number;
    t1_offset_px: number;
    tp_offset_px: number;
    dominant_curve: string;
  };
};

export type UploadUrlResponse = {
  uploadUrl: string;
  key?: string;
  s3Key?: string;
};

export const api = {
  createCase: (body: { notes?: string } = {}) =>
    http<{ caseId: string }>(`/cases`, {
      method: "POST",
      body: JSON.stringify(body),
    }),

  startCase: (caseId: string) =>
    http<{ caseId: string; executionArn?: string; status?: string }>(
      `/cases/${encodeURIComponent(caseId)}/start`,
      {
        method: "POST",
        body: JSON.stringify({}),
      }
    ),

  getUploadUrl: (caseId: string, body: { view: string; contentType?: string; filename?: string }) =>
    http<UploadUrlResponse>(`/cases/${encodeURIComponent(caseId)}/upload-url`, {
      method: "POST",
      body: JSON.stringify(body),
    }),

  getCaseStatus: (caseId: string) => http<CaseStatus>(`/cases/${encodeURIComponent(caseId)}`),
  getCaseAssets: (caseId: string) => http<CaseAssets>(`/cases/${encodeURIComponent(caseId)}/assets`),

  // FIX: include caseId in JSON body to satisfy backend Lambda contract
  submitLandmarks: (caseId: string, body: SubmitLandmarksRequest) =>
    http<SubmitLandmarksResponse>(`/cases/${encodeURIComponent(caseId)}/landmarks`, {
      method: "POST",
      body: JSON.stringify({
        ...body,
      }),
    }),
};