import ky, { type KyInstance, type Options } from "ky";
import { env } from "@/lib/env";
import { resolveApiPrefixUrl } from "@/lib/resolve-api-prefix-url";
import { API_PATHS } from "@/api/api-paths";
import { mapHttpStatusToMessage, normalizeApiRequestError } from "@/api/api-error";
import { getAccessToken } from "@/lib/auth/auth-storage";
import { expireSessionAndRedirectToLogin } from "@/lib/auth/expire-session";
import { traceHttpOperation } from "@/observability/http-transaction";

function isAuthLoginRequest(request: Request): boolean {
  return request.url.includes(API_PATHS.authentication.login);
}

/** Ky's beforeRequest sees request.body as a stream; check options.body for FormData. */
export function shouldStripJsonContentType(body: unknown): boolean {
  return body instanceof FormData;
}

export const api: KyInstance = ky.create({
  prefix: resolveApiPrefixUrl(env.apiUrl),
  headers: {
    Accept: "application/json",
    "Content-Type": "application/json",
  },
  hooks: {
    beforeRequest: [
      ({ request, options }) => {
        const token = getAccessToken();
        if (token) {
          request.headers.set("Authorization", token);
        }
        // Let the runtime set multipart boundary; default JSON Content-Type breaks FormData.
        if (shouldStripJsonContentType(options.body)) {
          request.headers.delete("Content-Type");
        }
      },
    ],
    beforeError: [({ error }) => normalizeApiRequestError(error)],
    afterResponse: [
      ({ request, response }) => {
        if (response.status !== 401 || isAuthLoginRequest(request)) {
          return response;
        }

        expireSessionAndRedirectToLogin();
        return response;
      },
    ],
  },
});

export type ApiRawMethod = "get" | "post" | "put" | "patch" | "delete";

export async function apiRequestRaw(
  method: ApiRawMethod,
  url: string,
  options?: Options,
  entryPoint?: string,
): Promise<Response> {
  return traceHttpOperation(
    {
      method: method.toUpperCase(),
      url,
      entryPoint: entryPoint ?? `api.${method}`,
    },
    async ({ reportStatus }) => {
      const response = await api[method](url, options);
      reportStatus(response.status);
      return response;
    },
  );
}

export async function apiGet<T>(url: string, options?: Options): Promise<T> {
  return traceHttpOperation(
    { method: "GET", url, entryPoint: "api.apiGet" },
    async ({ reportStatus }) => {
      const response = await api.get(url, options);
      reportStatus(response.status);
      return response.json<T>();
    },
  );
}

export async function apiPost<T>(url: string, body?: unknown, options?: Options): Promise<T> {
  return traceHttpOperation(
    { method: "POST", url, entryPoint: "api.apiPost" },
    async ({ reportStatus }) => {
      const response = await api.post(url, { ...options, json: body });
      reportStatus(response.status);
      return response.json<T>();
    },
  );
}

export async function apiPostForm<T>(url: string, body: FormData, options?: Options): Promise<T> {
  return traceHttpOperation(
    { method: "POST", url, entryPoint: "api.apiPostForm" },
    async ({ reportStatus }) => {
      const response = await api.post(url, { ...options, body });
      reportStatus(response.status);
      return response.json<T>();
    },
  );
}

export async function apiPut<T>(url: string, body?: unknown, options?: Options): Promise<T> {
  return traceHttpOperation(
    { method: "PUT", url, entryPoint: "api.apiPut" },
    async ({ reportStatus }) => {
      const response = await api.put(url, { ...options, json: body });
      reportStatus(response.status);
      return response.json<T>();
    },
  );
}

export async function apiPatch<T>(url: string, body?: unknown, options?: Options): Promise<T> {
  return traceHttpOperation(
    { method: "PATCH", url, entryPoint: "api.apiPatch" },
    async ({ reportStatus }) => {
      const response = await api.patch(url, { ...options, json: body });
      reportStatus(response.status);
      return response.json<T>();
    },
  );
}

export async function apiDelete<T>(url: string, options?: Options): Promise<T> {
  return traceHttpOperation(
    { method: "DELETE", url, entryPoint: "api.apiDelete" },
    async ({ reportStatus }) => {
      const response = await api.delete(url, options);
      reportStatus(response.status);
      return response.json<T>();
    },
  );
}

export async function apiPostNoContent(
  url: string,
  body?: unknown,
  options?: Options,
): Promise<void> {
  return traceHttpOperation(
    { method: "POST", url, entryPoint: "api.apiPostNoContent" },
    async ({ reportStatus }) => {
      const response = await api.post(url, { ...options, json: body });
      reportStatus(response.status);
      if (response.status === 204) {
        return;
      }

      const text = await response.text();
      if (!text.trim()) {
        return;
      }

      JSON.parse(text);
    },
  );
}

export async function apiDeleteNoContent(url: string, options?: Options): Promise<void> {
  return traceHttpOperation(
    { method: "DELETE", url, entryPoint: "api.apiDeleteNoContent" },
    async ({ reportStatus }) => {
      const response = await api.delete(url, options);
      reportStatus(response.status);
      if (response.status === 204) {
        return;
      }

      const text = await response.text();
      if (!text.trim()) {
        return;
      }

      JSON.parse(text);
    },
  );
}

export { mapHttpStatusToMessage };