package service

import (
	"context"
	"encoding/json"
	"os"
	"path/filepath"
	"testing"
	"time"

	"git.casaderoll.de/michael/urbm/internal/model"
	"git.casaderoll.de/michael/urbm/internal/queue"
	"git.casaderoll.de/michael/urbm/internal/store"
)

func TestEmptyBackupMetricsEncodeAsJSONArray(t *testing.T) {
	s := &Service{}
	encoded, err := json.Marshal(s.BackupMetrics())
	if err != nil {
		t.Fatal(err)
	}
	if string(encoded) != "[]" {
		t.Fatalf("empty backup metrics JSON = %s", encoded)
	}
}

func TestRepositoryLockHonorsContextCancellation(t *testing.T) {
	s := &Service{repositoryLocks: map[string]chan struct{}{}}
	repo := model.Repository{Type: model.RepositoryLocal, Location: "/repo"}
	unlock, err := s.lockRepository(context.Background(), repo)
	if err != nil {
		t.Fatal(err)
	}
	ctx, cancel := context.WithTimeout(context.Background(), 20*time.Millisecond)
	defer cancel()
	if _, err := s.lockRepository(ctx, repo); err == nil {
		t.Fatal("concurrent repository access ignored the request deadline")
	}
	unlock()
}

func TestBackupMetricsSurviveClearedRunSnapshot(t *testing.T) {
	dir := t.TempDir()
	st := store.New(dir)
	if err := st.Init(); err != nil {
		t.Fatal(err)
	}
	s := &Service{store: st, persistRuns: make(chan []model.Run, 1)}
	finished := time.Date(2026, 7, 13, 1, 30, 0, 0, time.UTC)
	run := model.Run{ID: "run-1", JobID: "job-1", TaskType: "backup", Status: "success", FinishedAt: &finished, BytesProcessed: 1024, FilesProcessed: 12}
	s.queuePersistence([]model.Run{run})
	before, err := os.ReadFile(filepath.Join(dir, "backup-metrics.jsonl"))
	if err != nil {
		t.Fatal(err)
	}
	s.queuePersistence(nil)
	after, err := os.ReadFile(filepath.Join(dir, "backup-metrics.jsonl"))
	if err != nil {
		t.Fatal(err)
	}
	if string(after) != string(before) {
		t.Fatal("clearing activities rewrote the backup metric file")
	}
	metrics := s.BackupMetrics()
	if len(metrics) != 1 || metrics[0].RunID != run.ID || metrics[0].FilesProcessed != 12 {
		t.Fatalf("backup metrics after clear = %#v", metrics)
	}
}

func TestLastRunUsesDurableMetricAfterActivityClear(t *testing.T) {
	created := time.Date(2026, 7, 13, 1, 0, 0, 0, time.UTC)
	finished := created.Add(3 * time.Hour)
	q := queue.New(nil, nil)
	q.RestoreHistory([]model.Run{{ID: "run-1", JobID: "job-1", Status: "success", CreatedAt: created}})
	s := &Service{queue: q, backupMetrics: []model.BackupMetric{{RunID: "run-1", JobID: "job-1", Status: "success", FinishedAt: finished}}}
	q.ClearHistory()
	if got := s.LastRun("job-1"); !got.Equal(finished) {
		t.Fatalf("last run after activity clear = %v, want %v", got, finished)
	}
}

func TestBackupMetricsOnlyCaptureCompletedSuccessfulBackupsOnce(t *testing.T) {
	st := store.New(t.TempDir())
	s := &Service{store: st}
	finished := time.Now().UTC()
	valid := model.Run{ID: "valid", JobID: "job-1", TaskType: "backup", Status: "warning", FinishedAt: &finished}
	s.captureBackupMetrics([]model.Run{
		valid,
		valid,
		{ID: "failed", TaskType: "backup", Status: "failed", FinishedAt: &finished},
		{ID: "active", TaskType: "backup", Status: "running"},
		{ID: "rsync", TaskType: "rsync", Status: "success", FinishedAt: &finished},
	})
	metrics := s.BackupMetrics()
	if len(metrics) != 1 || metrics[0].RunID != valid.ID {
		t.Fatalf("captured backup metrics = %#v", metrics)
	}
}

func TestPersistentRunLogsAreWrittenAndPruned(t *testing.T) {
	dir := t.TempDir()
	config := model.DefaultConfig()
	config.Settings.PersistentLogDir = dir
	s := &Service{config: config}
	finished := time.Now()
	run := model.Run{ID: "run-1", FinishedAt: &finished, LiveLog: []string{"first", "second"}}
	if err := s.persistRunLogs([]model.Run{run}); err != nil {
		t.Fatal(err)
	}
	path := filepath.Join(dir, "urbm-run-1.log")
	if contents, err := os.ReadFile(path); err != nil || string(contents) != "first\nsecond\n" {
		t.Fatalf("persistent log = %q, %v", contents, err)
	}
	if err := s.persistRunLogs(nil); err != nil {
		t.Fatal(err)
	}
	if _, err := os.Stat(path); !os.IsNotExist(err) {
		t.Fatalf("cleared run log still exists: %v", err)
	}
}

func TestQueuePersistenceDoesNotBlockWhenWriterIsBusy(t *testing.T) {
	s := &Service{persistRuns: make(chan []model.Run, 1)}
	s.persistRuns <- []model.Run{{ID: "old"}}
	done := make(chan struct{})
	go func() {
		s.queuePersistence([]model.Run{{ID: "latest"}})
		close(done)
	}()
	select {
	case <-done:
	case <-time.After(100 * time.Millisecond):
		t.Fatal("queue persistence blocked the queue callback")
	}
	runs := <-s.persistRuns
	if len(runs) != 1 || runs[0].ID != "latest" {
		t.Fatalf("queued persistence state = %#v", runs)
	}
}