package models

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

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

// Volume represents a volume mount for an app container.
type Volume struct {
	db *database.Database

	ID            int64
	AppID         string
	HostPath      string
	ContainerPath string
	ReadOnly      bool
}

// NewVolume creates a new Volume with a database reference.
func NewVolume(db *database.Database) *Volume {
	return &Volume{db: db}
}

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

	return v.update(ctx)
}

// Delete removes the volume from the database.
func (v *Volume) Delete(ctx context.Context) error {
	_, err := v.db.Exec(ctx, "DELETE FROM app_volumes WHERE id = ?", v.ID)

	return err
}

func (v *Volume) insert(ctx context.Context) error {
	query := `
		INSERT INTO app_volumes (app_id, host_path, container_path, readonly)
		VALUES (?, ?, ?, ?)`

	result, err := v.db.Exec(ctx, query,
		v.AppID, v.HostPath, v.ContainerPath, v.ReadOnly,
	)
	if err != nil {
		return err
	}

	id, err := result.LastInsertId()
	if err != nil {
		return err
	}

	v.ID = id

	return nil
}

func (v *Volume) update(ctx context.Context) error {
	query := `
		UPDATE app_volumes SET host_path = ?, container_path = ?, readonly = ?
		WHERE id = ?`

	_, err := v.db.Exec(ctx, query, v.HostPath, v.ContainerPath, v.ReadOnly, v.ID)

	return err
}

// FindVolume finds a volume by ID.
//
//nolint:nilnil // returning nil,nil is idiomatic for "not found" in Active Record
func FindVolume(
	ctx context.Context,
	db *database.Database,
	id int64,
) (*Volume, error) {
	vol := NewVolume(db)

	query := `
		SELECT id, app_id, host_path, container_path, readonly
		FROM app_volumes WHERE id = ?`

	row := db.QueryRow(ctx, query, id)

	err := row.Scan(
		&vol.ID, &vol.AppID, &vol.HostPath, &vol.ContainerPath, &vol.ReadOnly,
	)
	if err != nil {
		if errors.Is(err, sql.ErrNoRows) {
			return nil, nil
		}

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

	return vol, nil
}

// FindVolumesByAppID finds all volumes for an app.
func FindVolumesByAppID(
	ctx context.Context,
	db *database.Database,
	appID string,
) ([]*Volume, error) {
	query := `
		SELECT id, app_id, host_path, container_path, readonly
		FROM app_volumes WHERE app_id = ? ORDER BY container_path`

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

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

	var volumes []*Volume

	for rows.Next() {
		vol := NewVolume(db)

		scanErr := rows.Scan(
			&vol.ID, &vol.AppID, &vol.HostPath,
			&vol.ContainerPath, &vol.ReadOnly,
		)
		if scanErr != nil {
			return nil, scanErr
		}

		volumes = append(volumes, vol)
	}

	return volumes, rows.Err()
}

// DeleteVolumesByAppID deletes all volumes for an app.
func DeleteVolumesByAppID(
	ctx context.Context,
	db *database.Database,
	appID string,
) error {
	_, err := db.Exec(ctx, "DELETE FROM app_volumes WHERE app_id = ?", appID)

	return err
}