// Package app provides application management services.
package app

import (
	"context"
	"crypto/rand"
	"database/sql"
	"fmt"
	"log/slog"
	"time"

	"github.com/google/uuid"
	"github.com/oklog/ulid/v2"

	"go.uber.org/fx"

	"git.eeqj.de/sneak/upaas/internal/database"
	"git.eeqj.de/sneak/upaas/internal/logger"
	"git.eeqj.de/sneak/upaas/internal/models"
	"git.eeqj.de/sneak/upaas/internal/ssh"
)

// ServiceParams contains dependencies for Service.
type ServiceParams struct {
	fx.In

	Logger   *logger.Logger
	Database *database.Database
}

// Service provides app management functionality.
type Service struct {
	log    *slog.Logger
	db     *database.Database
	params *ServiceParams
}

// New creates a new app Service.
func New(_ fx.Lifecycle, params ServiceParams) (*Service, error) {
	return &Service{
		log:    params.Logger.Get(),
		db:     params.Database,
		params: &params,
	}, nil
}

// CreateAppInput contains the input for creating an app.
type CreateAppInput struct {
	Name           string
	RepoURL        string
	Branch         string
	DockerfilePath string
	DockerNetwork  string
	NtfyTopic      string
	SlackWebhook   string
}

// CreateApp creates a new application with generated SSH keys and webhook secret.
func (svc *Service) CreateApp(
	ctx context.Context,
	input CreateAppInput,
) (*models.App, error) {
	// Generate SSH key pair
	keyPair, err := ssh.GenerateKeyPair()
	if err != nil {
		return nil, fmt.Errorf("failed to generate SSH key pair: %w", err)
	}

	// Create app with ULID
	app := models.NewApp(svc.db)
	app.ID = ulid.MustNew(ulid.Timestamp(time.Now()), rand.Reader).String()
	app.Name = input.Name
	app.RepoURL = input.RepoURL

	app.Branch = input.Branch
	if app.Branch == "" {
		app.Branch = "main"
	}

	app.DockerfilePath = input.DockerfilePath
	if app.DockerfilePath == "" {
		app.DockerfilePath = "Dockerfile"
	}

	app.WebhookSecret = uuid.New().String()
	app.WebhookSecretHash = database.HashWebhookSecret(app.WebhookSecret)
	app.SSHPrivateKey = keyPair.PrivateKey
	app.SSHPublicKey = keyPair.PublicKey
	app.Status = models.AppStatusPending

	if input.DockerNetwork != "" {
		app.DockerNetwork = sql.NullString{String: input.DockerNetwork, Valid: true}
	}

	if input.NtfyTopic != "" {
		app.NtfyTopic = sql.NullString{String: input.NtfyTopic, Valid: true}
	}

	if input.SlackWebhook != "" {
		app.SlackWebhook = sql.NullString{String: input.SlackWebhook, Valid: true}
	}

	saveErr := app.Save(ctx)
	if saveErr != nil {
		return nil, fmt.Errorf("failed to save app: %w", saveErr)
	}

	svc.log.Info("app created", "id", app.ID, "name", app.Name)

	return app, nil
}

// UpdateAppInput contains the input for updating an app.
type UpdateAppInput struct {
	Name           string
	RepoURL        string
	Branch         string
	DockerfilePath string
	DockerNetwork  string
	NtfyTopic      string
	SlackWebhook   string
}

// UpdateApp updates an existing application.
func (svc *Service) UpdateApp(
	ctx context.Context,
	app *models.App,
	input UpdateAppInput,
) error {
	app.Name = input.Name
	app.RepoURL = input.RepoURL
	app.Branch = input.Branch
	app.DockerfilePath = input.DockerfilePath

	app.DockerNetwork = sql.NullString{
		String: input.DockerNetwork,
		Valid:  input.DockerNetwork != "",
	}
	app.NtfyTopic = sql.NullString{
		String: input.NtfyTopic,
		Valid:  input.NtfyTopic != "",
	}
	app.SlackWebhook = sql.NullString{
		String: input.SlackWebhook,
		Valid:  input.SlackWebhook != "",
	}

	saveErr := app.Save(ctx)
	if saveErr != nil {
		return fmt.Errorf("failed to save app: %w", saveErr)
	}

	svc.log.Info("app updated", "id", app.ID, "name", app.Name)

	return nil
}

// DeleteApp deletes an application and its related data.
func (svc *Service) DeleteApp(ctx context.Context, app *models.App) error {
	// Related data is deleted by CASCADE
	deleteErr := app.Delete(ctx)
	if deleteErr != nil {
		return fmt.Errorf("failed to delete app: %w", deleteErr)
	}

	svc.log.Info("app deleted", "id", app.ID, "name", app.Name)

	return nil
}

// GetApp retrieves an app by ID.
func (svc *Service) GetApp(ctx context.Context, appID string) (*models.App, error) {
	app, err := models.FindApp(ctx, svc.db, appID)
	if err != nil {
		return nil, fmt.Errorf("failed to find app: %w", err)
	}

	return app, nil
}

// GetAppByWebhookSecret retrieves an app by webhook secret.
func (svc *Service) GetAppByWebhookSecret(
	ctx context.Context,
	secret string,
) (*models.App, error) {
	app, err := models.FindAppByWebhookSecret(ctx, svc.db, secret)
	if err != nil {
		return nil, fmt.Errorf("failed to find app by webhook secret: %w", err)
	}

	return app, nil
}

// ListApps returns all apps.
func (svc *Service) ListApps(ctx context.Context) ([]*models.App, error) {
	apps, err := models.AllApps(ctx, svc.db)
	if err != nil {
		return nil, fmt.Errorf("failed to list apps: %w", err)
	}

	return apps, nil
}

// AddEnvVar adds an environment variable to an app.
func (svc *Service) AddEnvVar(
	ctx context.Context,
	appID, key, value string,
) error {
	envVar := models.NewEnvVar(svc.db)
	envVar.AppID = appID
	envVar.Key = key
	envVar.Value = value

	saveErr := envVar.Save(ctx)
	if saveErr != nil {
		return fmt.Errorf("failed to save env var: %w", saveErr)
	}

	return nil
}

// DeleteEnvVar deletes an environment variable.
func (svc *Service) DeleteEnvVar(ctx context.Context, envVarID int64) error {
	envVar, err := models.FindEnvVar(ctx, svc.db, envVarID)
	if err != nil {
		return fmt.Errorf("failed to find env var: %w", err)
	}

	if envVar == nil {
		return nil
	}

	deleteErr := envVar.Delete(ctx)
	if deleteErr != nil {
		return fmt.Errorf("failed to delete env var: %w", deleteErr)
	}

	return nil
}

// AddLabel adds a label to an app.
func (svc *Service) AddLabel(
	ctx context.Context,
	appID, key, value string,
) error {
	label := models.NewLabel(svc.db)
	label.AppID = appID
	label.Key = key
	label.Value = value

	saveErr := label.Save(ctx)
	if saveErr != nil {
		return fmt.Errorf("failed to save label: %w", saveErr)
	}

	return nil
}

// DeleteLabel deletes a label.
func (svc *Service) DeleteLabel(ctx context.Context, labelID int64) error {
	label, err := models.FindLabel(ctx, svc.db, labelID)
	if err != nil {
		return fmt.Errorf("failed to find label: %w", err)
	}

	if label == nil {
		return nil
	}

	deleteErr := label.Delete(ctx)
	if deleteErr != nil {
		return fmt.Errorf("failed to delete label: %w", deleteErr)
	}

	return nil
}

// AddVolume adds a volume mount to an app.
func (svc *Service) AddVolume(
	ctx context.Context,
	appID, hostPath, containerPath string,
	readonly bool,
) error {
	volume := models.NewVolume(svc.db)
	volume.AppID = appID
	volume.HostPath = hostPath
	volume.ContainerPath = containerPath
	volume.ReadOnly = readonly

	saveErr := volume.Save(ctx)
	if saveErr != nil {
		return fmt.Errorf("failed to save volume: %w", saveErr)
	}

	return nil
}

// DeleteVolume deletes a volume mount.
func (svc *Service) DeleteVolume(ctx context.Context, volumeID int64) error {
	volume, err := models.FindVolume(ctx, svc.db, volumeID)
	if err != nil {
		return fmt.Errorf("failed to find volume: %w", err)
	}

	if volume == nil {
		return nil
	}

	deleteErr := volume.Delete(ctx)
	if deleteErr != nil {
		return fmt.Errorf("failed to delete volume: %w", deleteErr)
	}

	return nil
}

// UpdateAppStatus updates the status of an app.
func (svc *Service) UpdateAppStatus(
	ctx context.Context,
	app *models.App,
	status models.AppStatus,
) error {
	app.Status = status

	saveErr := app.Save(ctx)
	if saveErr != nil {
		return fmt.Errorf("failed to save app status: %w", saveErr)
	}

	return nil
}