package models

import (
	"context"
	"database/sql"
	"errors"
	"fmt"
	"time"

	"git.eeqj.de/sneak/upaas/internal/database"
)

// DeploymentStatus represents the status of a deployment.
type DeploymentStatus string

// Deployment status constants.
const (
	DeploymentStatusBuilding  DeploymentStatus = "building"
	DeploymentStatusDeploying DeploymentStatus = "deploying"
	DeploymentStatusSuccess   DeploymentStatus = "success"
	DeploymentStatusFailed    DeploymentStatus = "failed"
)

// Display constants.
const (
	// secondsPerMinute is used for duration formatting.
	secondsPerMinute = 60
	// shortCommitLength is the number of characters to show for commit SHA.
	shortCommitLength = 12
)

// Deployment represents a deployment attempt for an app.
type Deployment struct {
	db *database.Database

	ID             int64
	AppID          string
	WebhookEventID sql.NullInt64
	CommitSHA      sql.NullString
	CommitURL      sql.NullString
	ImageID        sql.NullString
	ContainerID    sql.NullString
	Status         DeploymentStatus
	Logs           sql.NullString
	StartedAt      time.Time
	FinishedAt     sql.NullTime
}

// NewDeployment creates a new Deployment with a database reference.
func NewDeployment(db *database.Database) *Deployment {
	return &Deployment{
		db:     db,
		Status: DeploymentStatusBuilding,
	}
}

// Save inserts or updates the deployment in the database.
func (d *Deployment) Save(ctx context.Context) error {
	if d.ID == 0 {
		return d.insert(ctx)
	}

	return d.update(ctx)
}

// Reload refreshes the deployment from the database.
func (d *Deployment) Reload(ctx context.Context) error {
	query := `
		SELECT id, app_id, webhook_event_id, commit_sha, commit_url, image_id,
			container_id, status, logs, started_at, finished_at
		FROM deployments WHERE id = ?`

	row := d.db.QueryRow(ctx, query, d.ID)

	return d.scan(row)
}

// AppendLog appends a log line to the deployment logs.
func (d *Deployment) AppendLog(ctx context.Context, line string) error {
	var currentLogs string

	if d.Logs.Valid {
		currentLogs = d.Logs.String
	}

	d.Logs = sql.NullString{String: currentLogs + line + "\n", Valid: true}

	return d.Save(ctx)
}

// MarkFinished marks the deployment as finished with the given status.
func (d *Deployment) MarkFinished(
	ctx context.Context,
	status DeploymentStatus,
) error {
	d.Status = status
	d.FinishedAt = sql.NullTime{Time: time.Now(), Valid: true}

	return d.Save(ctx)
}

// Duration returns the duration of the deployment as a formatted string.
// Returns empty string if deployment is not finished.
func (d *Deployment) Duration() string {
	if !d.FinishedAt.Valid {
		return ""
	}

	duration := d.FinishedAt.Time.Sub(d.StartedAt)

	// Format as minutes and seconds
	minutes := int(duration.Minutes())
	seconds := int(duration.Seconds()) % secondsPerMinute

	if minutes > 0 {
		return fmt.Sprintf("%dm %ds", minutes, seconds)
	}

	return fmt.Sprintf("%ds", seconds)
}

// ShortCommit returns a truncated commit SHA for display.
// Returns "-" if no commit SHA is set.
func (d *Deployment) ShortCommit() string {
	if !d.CommitSHA.Valid || d.CommitSHA.String == "" {
		return "-"
	}

	sha := d.CommitSHA.String
	if len(sha) > shortCommitLength {
		return sha[:shortCommitLength]
	}

	return sha
}

// FinishedAtISO returns the finished time in ISO format for JavaScript parsing.
// Returns empty string if not finished yet.
func (d *Deployment) FinishedAtISO() string {
	if d.FinishedAt.Valid {
		return d.FinishedAt.Time.Format(time.RFC3339)
	}

	return ""
}

// FinishedAtFormatted returns the finished time formatted for display.
// Returns empty string if not finished yet.
func (d *Deployment) FinishedAtFormatted() string {
	if d.FinishedAt.Valid {
		return d.FinishedAt.Time.Format("2006-01-02 15:04:05")
	}

	return ""
}

func (d *Deployment) insert(ctx context.Context) error {
	query := `
		INSERT INTO deployments (
			app_id, webhook_event_id, commit_sha, commit_url, image_id,
			container_id, status, logs
		) VALUES (?, ?, ?, ?, ?, ?, ?, ?)`

	result, err := d.db.Exec(ctx, query,
		d.AppID, d.WebhookEventID, d.CommitSHA, d.CommitURL, d.ImageID,
		d.ContainerID, d.Status, d.Logs,
	)
	if err != nil {
		return err
	}

	insertID, err := result.LastInsertId()
	if err != nil {
		return fmt.Errorf("getting last insert id: %w", err)
	}

	d.ID = insertID

	return d.Reload(ctx)
}

func (d *Deployment) update(ctx context.Context) error {
	query := `
		UPDATE deployments SET
			image_id = ?, container_id = ?, status = ?, logs = ?, finished_at = ?
		WHERE id = ?`

	_, err := d.db.Exec(ctx, query,
		d.ImageID, d.ContainerID, d.Status, d.Logs, d.FinishedAt, d.ID,
	)

	return err
}

func (d *Deployment) scan(row *sql.Row) error {
	return row.Scan(
		&d.ID, &d.AppID, &d.WebhookEventID, &d.CommitSHA, &d.CommitURL, &d.ImageID,
		&d.ContainerID, &d.Status, &d.Logs, &d.StartedAt, &d.FinishedAt,
	)
}

// FindDeployment finds a deployment by ID.
//
//nolint:nilnil // returning nil,nil is idiomatic for "not found" in Active Record
func FindDeployment(
	ctx context.Context,
	deployDB *database.Database,
	deployID int64,
) (*Deployment, error) {
	deploy := NewDeployment(deployDB)
	deploy.ID = deployID

	row := deployDB.QueryRow(ctx, `
		SELECT id, app_id, webhook_event_id, commit_sha, commit_url, image_id,
			container_id, status, logs, started_at, finished_at
		FROM deployments WHERE id = ?`,
		deployID,
	)

	err := deploy.scan(row)
	if err != nil {
		if errors.Is(err, sql.ErrNoRows) {
			return nil, nil
		}

		return nil, fmt.Errorf("scanning deployment: %w", err)
	}

	return deploy, nil
}

// FindDeploymentsByAppID finds recent deployments for an app.
func FindDeploymentsByAppID(
	ctx context.Context,
	deployDB *database.Database,
	appID string,
	limit int,
) ([]*Deployment, error) {
	query := `
		SELECT id, app_id, webhook_event_id, commit_sha, commit_url, image_id,
			container_id, status, logs, started_at, finished_at
		FROM deployments WHERE app_id = ?
		ORDER BY started_at DESC, id DESC LIMIT ?`

	rows, err := deployDB.Query(ctx, query, appID, limit)
	if err != nil {
		return nil, fmt.Errorf("querying deployments by app: %w", err)
	}

	defer func() { _ = rows.Close() }()

	var deployments []*Deployment

	for rows.Next() {
		deploy := NewDeployment(deployDB)

		scanErr := rows.Scan(
			&deploy.ID, &deploy.AppID, &deploy.WebhookEventID,
			&deploy.CommitSHA, &deploy.CommitURL, &deploy.ImageID, &deploy.ContainerID,
			&deploy.Status, &deploy.Logs, &deploy.StartedAt, &deploy.FinishedAt,
		)
		if scanErr != nil {
			return nil, fmt.Errorf("scanning deployment row: %w", scanErr)
		}

		deployments = append(deployments, deploy)
	}

	rowsErr := rows.Err()
	if rowsErr != nil {
		return nil, fmt.Errorf("iterating deployment rows: %w", rowsErr)
	}

	return deployments, nil
}

// LatestDeploymentForApp finds the most recent deployment for an app.
//
//nolint:nilnil // returning nil,nil is idiomatic for "not found" in Active Record
func LatestDeploymentForApp(
	ctx context.Context,
	deployDB *database.Database,
	appID string,
) (*Deployment, error) {
	deploy := NewDeployment(deployDB)

	row := deployDB.QueryRow(ctx, `
		SELECT id, app_id, webhook_event_id, commit_sha, commit_url, image_id,
			container_id, status, logs, started_at, finished_at
		FROM deployments WHERE app_id = ?
		ORDER BY started_at DESC, id DESC LIMIT 1`,
		appID,
	)

	err := deploy.scan(row)
	if err != nil {
		if errors.Is(err, sql.ErrNoRows) {
			return nil, nil
		}

		return nil, fmt.Errorf("scanning latest deployment: %w", err)
	}

	return deploy, nil
}

// CountDeploymentsByAppID returns the total number of deployments for an app.
func CountDeploymentsByAppID(
	ctx context.Context,
	deployDB *database.Database,
	appID string,
) (int, error) {
	var count int

	row := deployDB.QueryRow(ctx,
		"SELECT COUNT(*) FROM deployments WHERE app_id = ?",
		appID,
	)

	err := row.Scan(&count)
	if err != nil {
		return 0, fmt.Errorf("counting deployments: %w", err)
	}

	return count, nil
}