package server_test

import (
	"encoding/json"
	"errors"
	"net/http"
	"net/http/httptest"
	"testing"

	"git.codelab.vc/pkg/httpx/server"
)

func TestHealthHandler(t *testing.T) {
	t.Run("liveness always returns 200", func(t *testing.T) {
		h := server.HealthHandler()

		w := httptest.NewRecorder()
		req := httptest.NewRequest(http.MethodGet, "/healthz", nil)
		h.ServeHTTP(w, req)

		if w.Code != http.StatusOK {
			t.Fatalf("got status %d, want %d", w.Code, http.StatusOK)
		}

		var resp map[string]any
		if err := json.NewDecoder(w.Body).Decode(&resp); err != nil {
			t.Fatalf("decode failed: %v", err)
		}
		if resp["status"] != "ok" {
			t.Fatalf("got status %q, want %q", resp["status"], "ok")
		}
	})

	t.Run("readiness returns 200 when all checks pass", func(t *testing.T) {
		h := server.HealthHandler(
			func() error { return nil },
			func() error { return nil },
		)

		w := httptest.NewRecorder()
		req := httptest.NewRequest(http.MethodGet, "/readyz", nil)
		h.ServeHTTP(w, req)

		if w.Code != http.StatusOK {
			t.Fatalf("got status %d, want %d", w.Code, http.StatusOK)
		}
	})

	t.Run("readiness returns 503 when a check fails", func(t *testing.T) {
		h := server.HealthHandler(
			func() error { return nil },
			func() error { return errors.New("db down") },
		)

		w := httptest.NewRecorder()
		req := httptest.NewRequest(http.MethodGet, "/readyz", nil)
		h.ServeHTTP(w, req)

		if w.Code != http.StatusServiceUnavailable {
			t.Fatalf("got status %d, want %d", w.Code, http.StatusServiceUnavailable)
		}

		var resp map[string]any
		if err := json.NewDecoder(w.Body).Decode(&resp); err != nil {
			t.Fatalf("decode failed: %v", err)
		}
		if resp["status"] != "unavailable" {
			t.Fatalf("got status %q, want %q", resp["status"], "unavailable")
		}
		errs, ok := resp["errors"].([]any)
		if !ok || len(errs) != 1 {
			t.Fatalf("expected 1 error, got %v", resp["errors"])
		}
		if errs[0] != "db down" {
			t.Fatalf("got error %q, want %q", errs[0], "db down")
		}
	})

	t.Run("readiness returns 200 with no checkers", func(t *testing.T) {
		h := server.HealthHandler()

		w := httptest.NewRecorder()
		req := httptest.NewRequest(http.MethodGet, "/readyz", nil)
		h.ServeHTTP(w, req)

		if w.Code != http.StatusOK {
			t.Fatalf("got status %d, want %d", w.Code, http.StatusOK)
		}
	})
}