package health

import (
	"fmt"
	"io"
	"net/http"
	"net/http/httptest"
	"testing"
)

func TestBasicHealthHandler(t *testing.T) {
	req := httptest.NewRequest(http.MethodGet, "/__health", nil)
	w := httptest.NewRecorder()

	basicHealth(w, req)

	res := w.Result()
	defer res.Body.Close()
	data, err := io.ReadAll(res.Body)
	if err != nil {
		t.Errorf("expected error to be nil got %v", err)
	}
	if string(data) != "ok" {
		t.Fail()
		t.Errorf("expected ok got %q", string(data))
	}
}

func TestProbeHandlers(t *testing.T) {
	// Test with separate handlers for each probe type
	srv := NewServer(nil,
		WithLivenessHandler(func(w http.ResponseWriter, r *http.Request) {
			w.WriteHeader(http.StatusOK)
		}),
		WithReadinessHandler(func(w http.ResponseWriter, r *http.Request) {
			w.WriteHeader(http.StatusOK)
		}),
		WithStartupHandler(func(w http.ResponseWriter, r *http.Request) {
			w.WriteHeader(http.StatusOK)
		}),
		WithServiceName("test-service"),
	)

	tests := []struct {
		handler        http.HandlerFunc
		expectedStatus int
		expectedBody   string
	}{
		{srv.createProbeHandler("liveness"), 200, `{"status":"alive"}`},
		{srv.createProbeHandler("readiness"), 200, `{"ready":true}`},
		{srv.createProbeHandler("startup"), 200, `{"started":true}`},
		{srv.createGeneralHandler(), 200, `{"service":"test-service","status":"healthy"}`},
	}

	for i, tt := range tests {
		t.Run(fmt.Sprintf("test_%d", i), func(t *testing.T) {
			req := httptest.NewRequest(http.MethodGet, "/", nil)
			w := httptest.NewRecorder()

			tt.handler(w, req)

			if w.Code != tt.expectedStatus {
				t.Errorf("expected status %d, got %d", tt.expectedStatus, w.Code)
			}

			body := w.Body.String()
			if body != tt.expectedBody+"\n" { // json.Encoder adds newline
				t.Errorf("expected body %q, got %q", tt.expectedBody, body)
			}
		})
	}
}

func TestProbeHandlerFallback(t *testing.T) {
	// Test fallback to general handler when no specific handler is configured
	generalHandler := func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
	}

	srv := NewServer(generalHandler, WithServiceName("test-service"))

	tests := []struct {
		handler        http.HandlerFunc
		expectedStatus int
		expectedBody   string
	}{
		{srv.createProbeHandler("liveness"), 200, `{"status":"alive"}`},
		{srv.createProbeHandler("readiness"), 200, `{"ready":true}`},
		{srv.createProbeHandler("startup"), 200, `{"started":true}`},
	}

	for i, tt := range tests {
		t.Run(fmt.Sprintf("fallback_%d", i), func(t *testing.T) {
			req := httptest.NewRequest(http.MethodGet, "/", nil)
			w := httptest.NewRecorder()

			tt.handler(w, req)

			if w.Code != tt.expectedStatus {
				t.Errorf("expected status %d, got %d", tt.expectedStatus, w.Code)
			}

			body := w.Body.String()
			if body != tt.expectedBody+"\n" { // json.Encoder adds newline
				t.Errorf("expected body %q, got %q", tt.expectedBody, body)
			}
		})
	}
}

func TestUnhealthyProbeHandlers(t *testing.T) {
	// Test with handlers that return unhealthy status
	srv := NewServer(nil,
		WithLivenessHandler(func(w http.ResponseWriter, r *http.Request) {
			w.WriteHeader(http.StatusServiceUnavailable)
		}),
		WithReadinessHandler(func(w http.ResponseWriter, r *http.Request) {
			w.WriteHeader(http.StatusServiceUnavailable)
		}),
		WithStartupHandler(func(w http.ResponseWriter, r *http.Request) {
			w.WriteHeader(http.StatusServiceUnavailable)
		}),
		WithServiceName("test-service"),
	)

	tests := []struct {
		handler        http.HandlerFunc
		expectedStatus int
		expectedBody   string
	}{
		{srv.createProbeHandler("liveness"), 503, `{"status":"unhealthy"}`},
		{srv.createProbeHandler("readiness"), 503, `{"ready":false}`},
		{srv.createProbeHandler("startup"), 503, `{"started":false}`},
	}

	for i, tt := range tests {
		t.Run(fmt.Sprintf("unhealthy_%d", i), func(t *testing.T) {
			req := httptest.NewRequest(http.MethodGet, "/", nil)
			w := httptest.NewRecorder()

			tt.handler(w, req)

			if w.Code != tt.expectedStatus {
				t.Errorf("expected status %d, got %d", tt.expectedStatus, w.Code)
			}

			body := w.Body.String()
			if body != tt.expectedBody+"\n" { // json.Encoder adds newline
				t.Errorf("expected body %q, got %q", tt.expectedBody, body)
			}
		})
	}
}