package monitoring

import (
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"testing"
	"time"
)

func TestAlertmanagerClient_ListAlerts(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/api/v2/alerts" {
			t.Errorf("unexpected path: %s", r.URL.Path)
		}

		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(`[
			{
				"annotations": {"summary": "Target is down"},
				"endsAt": "2024-01-01T01:00:00Z",
				"fingerprint": "abc123",
				"receivers": [{"name": "default"}],
				"startsAt": "2024-01-01T00:00:00Z",
				"status": {"inhibitedBy": [], "silencedBy": [], "state": "active"},
				"updatedAt": "2024-01-01T00:00:00Z",
				"generatorURL": "http://prometheus:9090/graph",
				"labels": {"alertname": "TargetDown", "severity": "critical", "instance": "node1:9100"}
			}
		]`))
	}))
	defer srv.Close()

	client := NewAlertmanagerClient(srv.URL)
	alerts, err := client.ListAlerts(context.Background(), AlertFilters{})
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}

	if len(alerts) != 1 {
		t.Fatalf("expected 1 alert, got %d", len(alerts))
	}
	if alerts[0].Fingerprint != "abc123" {
		t.Errorf("expected fingerprint=abc123, got %s", alerts[0].Fingerprint)
	}
	if alerts[0].Labels["alertname"] != "TargetDown" {
		t.Errorf("expected alertname=TargetDown, got %s", alerts[0].Labels["alertname"])
	}
	if alerts[0].Status.State != "active" {
		t.Errorf("expected state=active, got %s", alerts[0].Status.State)
	}
}

func TestAlertmanagerClient_ListAlertsWithFilters(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		q := r.URL.Query()
		if q.Get("active") != "true" {
			t.Errorf("expected active=true, got %s", q.Get("active"))
		}
		if q.Get("silenced") != "false" {
			t.Errorf("expected silenced=false, got %s", q.Get("silenced"))
		}

		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(`[]`))
	}))
	defer srv.Close()

	client := NewAlertmanagerClient(srv.URL)
	active := true
	silenced := false
	_, err := client.ListAlerts(context.Background(), AlertFilters{
		Active:   &active,
		Silenced: &silenced,
	})
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
}

func TestAlertmanagerClient_ListSilences(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/api/v2/silences" {
			t.Errorf("unexpected path: %s", r.URL.Path)
		}

		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(`[
			{
				"id": "silence-1",
				"matchers": [{"name": "alertname", "value": "TargetDown", "isRegex": false}],
				"startsAt": "2024-01-01T00:00:00Z",
				"endsAt": "2024-01-01T02:00:00Z",
				"createdBy": "admin",
				"comment": "Maintenance window",
				"status": {"state": "active"}
			}
		]`))
	}))
	defer srv.Close()

	client := NewAlertmanagerClient(srv.URL)
	silences, err := client.ListSilences(context.Background())
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}

	if len(silences) != 1 {
		t.Fatalf("expected 1 silence, got %d", len(silences))
	}
	if silences[0].ID != "silence-1" {
		t.Errorf("expected id=silence-1, got %s", silences[0].ID)
	}
	if silences[0].CreatedBy != "admin" {
		t.Errorf("expected createdBy=admin, got %s", silences[0].CreatedBy)
	}
}

func TestAlertmanagerClient_CreateSilence(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Method != http.MethodPost {
			t.Errorf("expected POST, got %s", r.Method)
		}
		if r.URL.Path != "/api/v2/silences" {
			t.Errorf("unexpected path: %s", r.URL.Path)
		}
		if r.Header.Get("Content-Type") != "application/json" {
			t.Errorf("expected Content-Type=application/json, got %s", r.Header.Get("Content-Type"))
		}

		var silence Silence
		if err := json.NewDecoder(r.Body).Decode(&silence); err != nil {
			t.Fatalf("failed to decode request body: %v", err)
		}
		if silence.CreatedBy != "admin" {
			t.Errorf("expected createdBy=admin, got %s", silence.CreatedBy)
		}

		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(`{"silenceID": "new-silence-id"}`))
	}))
	defer srv.Close()

	client := NewAlertmanagerClient(srv.URL)
	id, err := client.CreateSilence(context.Background(), Silence{
		Matchers: []Matcher{
			{Name: "alertname", Value: "TargetDown", IsRegex: false},
		},
		StartsAt:  time.Now(),
		EndsAt:    time.Now().Add(2 * time.Hour),
		CreatedBy: "admin",
		Comment:   "Test silence",
	})
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if id != "new-silence-id" {
		t.Errorf("expected id=new-silence-id, got %s", id)
	}
}

func TestAlertmanagerClient_HTTPError(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusInternalServerError)
		_, _ = w.Write([]byte("internal error"))
	}))
	defer srv.Close()

	client := NewAlertmanagerClient(srv.URL)
	_, err := client.ListAlerts(context.Background(), AlertFilters{})
	if err == nil {
		t.Fatal("expected error, got nil")
	}
}