export const PROJECT_HEALTH_MAX_AGE_MS = 15 * 60 * 1000;

export interface ProjectHealthCheck {
  status: number | null;
  contentType: string | null;
  checkedAt: string;
  finalUrl?: string;
  latencyMs?: number;
  error?: string;
}

export interface ProjectHealthSnapshot {
  checkedAt: string;
  projects: Record<string, ProjectHealthCheck>;
}

export type DemoAvailability = "available" | "unavailable" | "unknown" | "none";

export function getDemoAvailability(
  demoUrl: string | null | undefined,
  check: ProjectHealthCheck | undefined,
): DemoAvailability {
  if (!demoUrl) return "none";
  if (!check) return "unknown";
  if (check.error || check.status === null) return "unknown";
  return check.status === 200 &&
    check.contentType?.split(";", 1)[0].trim().toLowerCase() === "text/html"
    ? "available"
    : "unavailable";
}

interface ProjectDemo {
  id: string;
  demoUrl: string;
}

interface HealthResponse {
  status: number;
  url: string;
  headers: { get(name: string): string | null };
  body?: { cancel?: () => unknown } | null;
}

type HealthFetcher = (
  url: string,
  init: RequestInit,
) => Promise<HealthResponse>;

export async function createProjectHealthSnapshot(
  projects: ProjectDemo[],
  fetcher: HealthFetcher = (url, init) => fetch(url, init),
  now = new Date(),
): Promise<ProjectHealthSnapshot> {
  const checkedAt = now.toISOString();
  const checks = await Promise.all(
    projects.map(async (project) => {
      try {
        const response = await fetcher(project.demoUrl, {
          redirect: "follow",
          signal: AbortSignal.timeout(10_000),
          headers: { "user-agent": "evandro-project-health/1.0" },
        });
        await response.body?.cancel?.();

        return [
          project.id,
          {
            status: response.status,
            contentType: response.headers.get("content-type"),
            checkedAt,
            finalUrl: response.url,
          },
        ] as const;
      } catch (error) {
        return [
          project.id,
          {
            status: null,
            contentType: null,
            checkedAt,
            error:
              error instanceof Error ? error.message : "Health check failed",
          },
        ] as const;
      }
    }),
  );

  return { checkedAt, projects: Object.fromEntries(checks) };
}