package task

import (
	"context"
	"database/sql"
	"testing"
	"time"

	_ "github.com/mattn/go-sqlite3"

	"trankilou.fr/lassistanoque/backend/internal/adapter/database/turso"
	"trankilou.fr/lassistanoque/backend/internal/domain"
)

type fakeChatRunner struct {
	prompts []string
}

func (f *fakeChatRunner) NewChat(userID, teamID, agentID, taskID string) (*domain.Chat, error) {
	return &domain.Chat{ID: "chat-1", TeamID: teamID, UserID: userID, TaskID: taskID}, nil
}

func (f *fakeChatRunner) AddChatMessage(
	ctx context.Context,
	userID, teamID, chatID, agentID, prompt string,
	params *domain.ChatParams,
) (*domain.Message, error) {
	f.prompts = append(f.prompts, prompt)
	return &domain.Message{}, nil
}

func newTestRepo(t *testing.T) domain.TaskRepository {
	t.Helper()
	// cache partagé : l'ordonnanceur tourne dans sa propre goroutine et
	// doit voir la même base que le test (une :memory: classique est
	// propre à chaque connexion du pool)
	db, err := sql.Open("sqlite3", "file::memory:?cache=shared&_busy_timeout=5000")
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() { db.Close() })

	schema := `
	create table tasks (
		id text not null primary key, team_id text not null, model_id text not null,
		label text not null, prompt text not null, cron text not null,
		repeat integer not null default 1, status text not null, next_datetime numeric,
		last_datetime numeric,
		_date_created numeric not null default current_timestamp, _date_updated numeric,
		_version text not null);
	create table user_teams (
		id text not null primary key, user_id text not null, team_id text not null,
		administrator bool default 0, _date_created numeric not null default current_timestamp,
		_date_updated numeric, _version text not null);
	insert into user_teams (id, user_id, team_id, _date_created, _version)
		values ('ut1','user-1','team-1','2026-01-01 10:00:00','v');
	`
	if _, err := db.Exec(schema); err != nil {
		t.Fatal(err)
	}
	return turso.NewTursoTaskRepository(db)
}

func TestCreateTaskValidation(t *testing.T) {
	svc := NewService(newTestRepo(t))

	if _, err := svc.CreateTask("user-1", "team-1", &domain.Task{Label: "l", Prompt: "p", Cron: "invalid"}); err == nil {
		t.Errorf("invalid cron spec should fail")
	}
	if _, err := svc.CreateTask("user-1", "team-1", &domain.Task{Prompt: "p", Cron: "0 8 * * *"}); err == nil {
		t.Errorf("missing label should fail")
	}
	if _, err := svc.CreateTask("user-1", "team-1", &domain.Task{Label: "l", Cron: "0 8 * * *"}); err == nil {
		t.Errorf("missing prompt should fail")
	}
}

func TestCreateTaskRecurring(t *testing.T) {
	repo := newTestRepo(t)
	svc := NewService(repo)

	created, err := svc.CreateTask("user-1", "team-1", &domain.Task{
		ModelID: "m1",
		Label:   "Meteo du matin",
		Prompt:  "Donne-moi la meteo",
		Cron:    "0 8 * * *",
		Repeat:  true,
	})
	if err != nil {
		t.Fatal(err)
	}
	if created.Status != domain.TaskStatusActive {
		t.Errorf("status = %s", created.Status)
	}
	if created.NextDatetime == nil || created.NextDatetime.Before(time.Now()) {
		t.Errorf("next datetime should be in the future, got %v", created.NextDatetime)
	}

	tasks, err := svc.ListTasks("user-1", "team-1")
	if err != nil {
		t.Fatal(err)
	}
	if len(tasks) != 1 || tasks[0].ID != created.ID {
		t.Fatalf("expected 1 task %s, got %v", created.ID, tasks)
	}
}

func TestOneShotExecution(t *testing.T) {
	repo := newTestRepo(t)
	svc := NewService(repo)
	fake := &fakeChatRunner{}
	svc.SetChatService(fake)

	_, err := svc.CreateTask("user-1", "team-1", &domain.Task{
		Label:  "Ponctuel",
		Prompt: "Fais quelque chose",
		Cron:   "@every 1s",
		Repeat: false,
	})
	if err != nil {
		t.Fatal(err)
	}

	svc.Start()
	defer svc.Stop()

	// attend l'exécution
	deadline := time.Now().Add(5 * time.Second)
	for time.Now().Before(deadline) {
		if len(fake.prompts) > 0 {
			break
		}
		time.Sleep(100 * time.Millisecond)
	}
	if len(fake.prompts) == 0 || fake.prompts[0] != "Fais quelque chose" {
		t.Fatalf("task did not execute, prompts=%v", fake.prompts)
	}

	// statut "done" après une exécution sans répétition
	// (runTask persiste le statut juste après l'exécution : on l'attend)
	var done *domain.Task
	deadline = time.Now().Add(5 * time.Second)
	for time.Now().Before(deadline) {
		tasks, _ := repo.ListTasks("user-1", "team-1")
		done = nil
		for _, tk := range tasks {
			done = tk
		}
		if done != nil && done.Status == domain.TaskStatusDone {
			break
		}
		time.Sleep(100 * time.Millisecond)
	}
	if done == nil || done.Status != domain.TaskStatusDone {
		t.Fatalf("expected status done, got %+v", done)
	}

	// pas de deuxième exécution
	time.Sleep(2 * time.Second)
	if len(fake.prompts) != 1 {
		t.Fatalf("one-shot task ran %d times", len(fake.prompts))
	}
}

func TestUpdateTask(t *testing.T) {
	repo := newTestRepo(t)
	svc := NewService(repo)

	created, err := svc.CreateTask("user-1", "team-1", &domain.Task{
		Label: "Ancien", Prompt: "ancien prompt", Cron: "0 8 * * *", Repeat: true,
	})
	if err != nil {
		t.Fatal(err)
	}

	updated, err := svc.UpdateTask("user-1", "team-1", &domain.Task{
		ID: created.ID, Label: "Nouveau", Prompt: "nouveau prompt", Cron: "0 6 * * *", Repeat: false,
	})
	if err != nil {
		t.Fatal(err)
	}
	if updated.Label != "Nouveau" || updated.Prompt != "nouveau prompt" ||
		updated.Cron != "0 6 * * *" || updated.Repeat {
		t.Fatalf("update not applied: %+v", updated)
	}
	if updated.NextDatetime == nil || updated.NextDatetime.Hour() != 6 {
		t.Fatalf("next datetime should be recalculated at 6am, got %v", updated.NextDatetime)
	}

	// cron invalide refusé
	if _, err := svc.UpdateTask("user-1", "team-1", &domain.Task{
		ID: created.ID, Label: "x", Prompt: "y", Cron: "pasunecron", Repeat: true,
	}); err == nil {
		t.Errorf("invalid cron spec should fail")
	}

	// une tâche done est réactivée par une mise à jour
	done := updated
	done.Status = domain.TaskStatusDone
	if _, err := repo.UpdateTask(done); err != nil {
		t.Fatal(err)
	}
	reactivated, err := svc.UpdateTask("user-1", "team-1", &domain.Task{
		ID: created.ID, Label: "Reprise", Prompt: "p", Cron: "0 9 * * *", Repeat: true,
	})
	if err != nil {
		t.Fatal(err)
	}
	if reactivated.Status != domain.TaskStatusActive {
		t.Fatalf("done task should be reactivated, got %s", reactivated.Status)
	}
}

func TestDeleteTask(t *testing.T) {
	repo := newTestRepo(t)
	svc := NewService(repo)

	created, err := svc.CreateTask("user-1", "team-1", &domain.Task{
		Label: "l", Prompt: "p", Cron: "0 8 * * *", Repeat: true,
	})
	if err != nil {
		t.Fatal(err)
	}
	if err := svc.DeleteTask("user-1", "team-1", created.ID); err != nil {
		t.Fatal(err)
	}
	tasks, _ := svc.ListTasks("user-1", "team-1")
	if len(tasks) != 0 {
		t.Fatalf("expected 0 tasks after delete, got %d", len(tasks))
	}
}

// createMissedRecurringTask insère une tâche récurrente dont la dernière
// exécution remonte à plus d'une heure, avec une occurrence toutes les 30
// minutes : des exécutions ont été manquées, comme pendant un arrêt.
func createMissedRecurringTask(t *testing.T, repo domain.TaskRepository, prompt string) *domain.Task {
	t.Helper()
	last := time.Now().Add(-65 * time.Minute)
	task := &domain.Task{
		TeamID: "team-1", ModelID: "m1",
		Label: "Manquee", Prompt: prompt,
		Cron: "@every 30m", Repeat: true,
		Status:       domain.TaskStatusActive,
		LastDatetime: &last,
	}
	created, err := repo.CreateTask(task)
	if err != nil {
		t.Fatal(err)
	}
	return created
}

// createMissedOneShotTask insère une tâche ponctuelle active dont l'échéance
// est passée, comme après un arrêt du serveur.
func createMissedOneShotTask(t *testing.T, repo domain.TaskRepository, prompt string) *domain.Task {
	t.Helper()
	past := time.Now().Add(-2 * time.Hour)
	task := &domain.Task{
		TeamID: "team-1", ModelID: "m1",
		Label: "Manquee", Prompt: prompt,
		Cron: "@every 1h", Repeat: false,
		Status:       domain.TaskStatusActive,
		NextDatetime: &past,
	}
	created, err := repo.CreateTask(task)
	if err != nil {
		t.Fatal(err)
	}
	return created
}

// waitPrompts attend que le fake chat runner ait enregistré n prompts.
func waitPrompts(t *testing.T, fake *fakeChatRunner, n int) bool {
	t.Helper()
	deadline := time.Now().Add(5 * time.Second)
	for time.Now().Before(deadline) {
		if len(fake.prompts) >= n {
			return true
		}
		time.Sleep(100 * time.Millisecond)
	}
	return false
}

func TestStartCatchUpMissedRecurringTask(t *testing.T) {
	repo := newTestRepo(t)
	svc := NewService(repo)
	fake := &fakeChatRunner{}
	svc.SetChatService(fake)

	// dernière exécution il y a 65 min, occurrence toutes les 30 min :
	// go-cron (WithPrev + MissedRunOnce) doit rattraper au démarrage
	createMissedRecurringTask(t, repo, "prompt rattrapage")

	svc.Start()
	defer svc.Stop()

	if !waitPrompts(t, fake, 1) {
		t.Fatalf("missed task did not execute at startup, prompts=%v", fake.prompts)
	}
	if fake.prompts[0] != "prompt rattrapage" {
		t.Fatalf("unexpected prompt %q", fake.prompts[0])
	}

	// une seule exécution de rattrapage (pas une par occurrence manquée)
	time.Sleep(1 * time.Second)
	if len(fake.prompts) != 1 {
		t.Fatalf("catch-up ran %d times, expected 1", len(fake.prompts))
	}
}

func TestStartCatchUpMissedOneShotTask(t *testing.T) {
	repo := newTestRepo(t)
	svc := NewService(repo)
	fake := &fakeChatRunner{}
	svc.SetChatService(fake)

	created := createMissedOneShotTask(t, repo, "ponctuel manque")

	svc.Start()
	defer svc.Stop()

	if !waitPrompts(t, fake, 1) {
		t.Fatalf("missed one-shot task did not execute at startup, prompts=%v", fake.prompts)
	}

	// la tâche passe "done" et n'est pas replanifiée
	deadline := time.Now().Add(5 * time.Second)
	var done *domain.Task
	for time.Now().Before(deadline) {
		done, _ = svc.GetTask("user-1", "team-1", created.ID)
		if done != nil && done.Status == domain.TaskStatusDone {
			break
		}
		time.Sleep(100 * time.Millisecond)
	}
	if done == nil || done.Status != domain.TaskStatusDone {
		t.Fatalf("expected status done after catch-up, got %+v", done)
	}
	time.Sleep(1 * time.Second)
	if len(fake.prompts) != 1 {
		t.Fatalf("one-shot catch-up ran %d times", len(fake.prompts))
	}
}

func TestStartDoesNotCatchUpFutureTask(t *testing.T) {
	repo := newTestRepo(t)
	svc := NewService(repo)
	fake := &fakeChatRunner{}
	svc.SetChatService(fake)

	// dernière exécution récente, occurrence dans une heure :
	// rien à rattraper, pas d'exécution immédiate
	last := time.Now().Add(-10 * time.Minute)
	_, err := repo.CreateTask(&domain.Task{
		TeamID: "team-1", ModelID: "m1",
		Label: "Future", Prompt: "trop tot",
		Cron: "@every 1h", Repeat: true,
		Status:       domain.TaskStatusActive,
		LastDatetime: &last,
	})
	if err != nil {
		t.Fatal(err)
	}

	svc.Start()
	defer svc.Stop()

	time.Sleep(1 * time.Second)
	if len(fake.prompts) != 0 {
		t.Fatalf("task with no missed occurrence should not run, prompts=%v", fake.prompts)
	}
}

func TestRunTaskPersistsLastAndNextDatetime(t *testing.T) {
	repo := newTestRepo(t)
	svc := NewService(repo)
	fake := &fakeChatRunner{}
	svc.SetChatService(fake)

	_, err := svc.CreateTask("user-1", "team-1", &domain.Task{
		Label: "Repetitive", Prompt: "encore", Cron: "@every 1s", Repeat: true,
	})
	if err != nil {
		t.Fatal(err)
	}

	svc.Start()
	defer svc.Stop()

	if !waitPrompts(t, fake, 1) {
		t.Fatalf("task did not execute, prompts=%v", fake.prompts)
	}

	// après une exécution, la dernière exécution et la prochaine échéance
	// doivent être persistées (last_datetime nil à la création)
	deadline := time.Now().Add(5 * time.Second)
	ok := false
	for time.Now().Before(deadline) {
		tasks, _ := repo.ListTasks("user-1", "team-1")
		if len(tasks) == 1 && tasks[0].LastDatetime != nil && tasks[0].NextDatetime != nil && tasks[0].NextDatetime.After(time.Now()) {
			ok = true
			break
		}
		time.Sleep(100 * time.Millisecond)
	}
	if !ok {
		t.Fatal("last_datetime/next_datetime should be persisted after each execution")
	}
}