package httpapi

import (
	"context"
	"errors"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
	"time"
)

func TestHealthRemainsLiveWithoutDatabase(t *testing.T) {
	handler := NewHandler(func(context.Context) error {
		t.Fatal("liveness must not query the database")
		return nil
	})
	response := httptest.NewRecorder()
	handler.ServeHTTP(response, httptest.NewRequest(http.MethodGet, "/healthz", nil))
	if response.Code != http.StatusOK || response.Body.String() != "{\"status\":\"ok\"}\n" {
		t.Fatalf("unexpected response: %d %s", response.Code, response.Body.String())
	}
}

func TestReadinessReflectsDatabaseState(t *testing.T) {
	for _, tc := range []struct {
		name string
		err  error
		code int
		body string
	}{
		{"ready", nil, http.StatusOK, "{\"status\":\"ok\"}\n"},
		{"unavailable", errors.New("private database details"), http.StatusServiceUnavailable, "{\"status\":\"unavailable\"}\n"},
	} {
		t.Run(tc.name, func(t *testing.T) {
			called := false
			handler := NewHandler(func(ctx context.Context) error {
				called = true
				deadline, ok := ctx.Deadline()
				if !ok || time.Until(deadline) > 2*time.Second {
					t.Fatal("database check must have a bounded deadline")
				}
				return tc.err
			})
			response := httptest.NewRecorder()
			handler.ServeHTTP(response, httptest.NewRequest(http.MethodGet, "/readyz", nil))
			if !called || response.Code != tc.code || response.Body.String() != tc.body {
				t.Fatalf("unexpected response: %d %s", response.Code, response.Body.String())
			}
			if !strings.HasPrefix(response.Header().Get("Content-Type"), "application/json") {
				t.Fatal("health response must be JSON")
			}
		})
	}
}

func TestReadinessPreservesRequestCancellation(t *testing.T) {
	ctx, cancel := context.WithCancel(context.Background())
	cancel()
	handler := NewHandler(func(ctx context.Context) error { return ctx.Err() })
	response := httptest.NewRecorder()
	request := httptest.NewRequest(http.MethodGet, "/readyz", nil).WithContext(ctx)
	handler.ServeHTTP(response, request)
	if response.Code != http.StatusServiceUnavailable {
		t.Fatalf("got %d, want 503", response.Code)
	}
}