package metrics

import (
	"context"
	"io"
	"net/http"
	"strings"
	"testing"
	"time"

	"git.t-juice.club/torjus/homelab-deploy/internal/messages"
	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/testutil"
)

func TestCollector_SetInfo(t *testing.T) {
	reg := prometheus.NewRegistry()
	c := NewCollector(reg)

	c.SetInfo("testhost", "test", "web", "1.0.0")

	expected := `
# HELP homelab_deploy_info Static instance metadata
# TYPE homelab_deploy_info gauge
homelab_deploy_info{hostname="testhost",role="web",tier="test",version="1.0.0"} 1
`
	if err := testutil.GatherAndCompare(reg, strings.NewReader(expected), "homelab_deploy_info"); err != nil {
		t.Errorf("unexpected metrics: %v", err)
	}
}

func TestCollector_RecordDeploymentStart(t *testing.T) {
	reg := prometheus.NewRegistry()
	c := NewCollector(reg)

	c.RecordDeploymentStart()

	expected := `
# HELP homelab_deploy_deployment_in_progress 1 if deployment running, 0 otherwise
# TYPE homelab_deploy_deployment_in_progress gauge
homelab_deploy_deployment_in_progress 1
`
	if err := testutil.GatherAndCompare(reg, strings.NewReader(expected), "homelab_deploy_deployment_in_progress"); err != nil {
		t.Errorf("unexpected metrics: %v", err)
	}
}

func TestCollector_RecordDeploymentEnd_Success(t *testing.T) {
	reg := prometheus.NewRegistry()
	c := NewCollector(reg)

	c.RecordDeploymentStart()
	c.RecordDeploymentEnd(messages.ActionSwitch, true, 120.5)

	// Check in_progress is 0
	inProgressExpected := `
# HELP homelab_deploy_deployment_in_progress 1 if deployment running, 0 otherwise
# TYPE homelab_deploy_deployment_in_progress gauge
homelab_deploy_deployment_in_progress 0
`
	if err := testutil.GatherAndCompare(reg, strings.NewReader(inProgressExpected), "homelab_deploy_deployment_in_progress"); err != nil {
		t.Errorf("unexpected in_progress metrics: %v", err)
	}

	// Check counter incremented
	counterExpected := `
# HELP homelab_deploy_deployments_total Total deployment requests processed
# TYPE homelab_deploy_deployments_total counter
homelab_deploy_deployments_total{action="switch",error_code="",status="completed"} 1
`
	if err := testutil.GatherAndCompare(reg, strings.NewReader(counterExpected), "homelab_deploy_deployments_total"); err != nil {
		t.Errorf("unexpected counter metrics: %v", err)
	}
}

func TestCollector_RecordDeploymentEnd_Failure(t *testing.T) {
	reg := prometheus.NewRegistry()
	c := NewCollector(reg)

	c.RecordDeploymentStart()
	c.RecordDeploymentEnd(messages.ActionBoot, false, 60.0)

	counterExpected := `
# HELP homelab_deploy_deployments_total Total deployment requests processed
# TYPE homelab_deploy_deployments_total counter
homelab_deploy_deployments_total{action="boot",error_code="",status="failed"} 1
`
	if err := testutil.GatherAndCompare(reg, strings.NewReader(counterExpected), "homelab_deploy_deployments_total"); err != nil {
		t.Errorf("unexpected counter metrics: %v", err)
	}
}

func TestCollector_RecordDeploymentFailure(t *testing.T) {
	reg := prometheus.NewRegistry()
	c := NewCollector(reg)

	c.RecordDeploymentStart()
	c.RecordDeploymentFailure(messages.ActionSwitch, messages.ErrorBuildFailed, 300.0)

	counterExpected := `
# HELP homelab_deploy_deployments_total Total deployment requests processed
# TYPE homelab_deploy_deployments_total counter
homelab_deploy_deployments_total{action="switch",error_code="build_failed",status="failed"} 1
`
	if err := testutil.GatherAndCompare(reg, strings.NewReader(counterExpected), "homelab_deploy_deployments_total"); err != nil {
		t.Errorf("unexpected counter metrics: %v", err)
	}
}

func TestCollector_RecordRejection(t *testing.T) {
	reg := prometheus.NewRegistry()
	c := NewCollector(reg)

	c.RecordRejection(messages.ActionSwitch, messages.ErrorAlreadyRunning)

	expected := `
# HELP homelab_deploy_deployments_total Total deployment requests processed
# TYPE homelab_deploy_deployments_total counter
homelab_deploy_deployments_total{action="switch",error_code="already_running",status="rejected"} 1
`
	if err := testutil.GatherAndCompare(reg, strings.NewReader(expected), "homelab_deploy_deployments_total"); err != nil {
		t.Errorf("unexpected metrics: %v", err)
	}
}

func TestServer_StartShutdown(t *testing.T) {
	srv := NewServer(ServerConfig{
		Addr: ":0", // Let OS pick a free port
	})

	if err := srv.Start(); err != nil {
		t.Fatalf("failed to start server: %v", err)
	}

	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()

	if err := srv.Shutdown(ctx); err != nil {
		t.Errorf("failed to shutdown server: %v", err)
	}
}

func TestServer_Endpoints(t *testing.T) {
	srv := NewServer(ServerConfig{
		Addr: "127.0.0.1:19972", // Use a fixed port for testing
	})

	if err := srv.Start(); err != nil {
		t.Fatalf("failed to start server: %v", err)
	}

	defer func() {
		ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
		defer cancel()
		_ = srv.Shutdown(ctx)
	}()

	// Give server time to start
	time.Sleep(50 * time.Millisecond)

	t.Run("health endpoint", func(t *testing.T) {
		resp, err := http.Get("http://127.0.0.1:19972/health")
		if err != nil {
			t.Fatalf("failed to get health endpoint: %v", err)
		}
		defer func() { _ = resp.Body.Close() }()

		if resp.StatusCode != http.StatusOK {
			t.Errorf("expected status 200, got %d", resp.StatusCode)
		}

		body, _ := io.ReadAll(resp.Body)
		if string(body) != "ok" {
			t.Errorf("expected body 'ok', got %q", string(body))
		}
	})

	t.Run("metrics endpoint", func(t *testing.T) {
		// Set some info to have metrics to display
		srv.Collector().SetInfo("testhost", "test", "web", "1.0.0")

		resp, err := http.Get("http://127.0.0.1:19972/metrics")
		if err != nil {
			t.Fatalf("failed to get metrics endpoint: %v", err)
		}
		defer func() { _ = resp.Body.Close() }()

		if resp.StatusCode != http.StatusOK {
			t.Errorf("expected status 200, got %d", resp.StatusCode)
		}

		body, _ := io.ReadAll(resp.Body)
		bodyStr := string(body)

		if !strings.Contains(bodyStr, "homelab_deploy_info") {
			t.Error("expected metrics to contain homelab_deploy_info")
		}
	})
}

func TestServer_Collector(t *testing.T) {
	srv := NewServer(ServerConfig{
		Addr: ":0",
	})

	collector := srv.Collector()
	if collector == nil {
		t.Error("expected non-nil collector")
	}
}