package postgres

import (
	"context"
	"database/sql"
	"embed"
	"errors"
	pb "go.unistack.org/unistack-org/pkgdash/proto/go_generate"

	"github.com/golang-migrate/migrate/v4"
	mpgx "github.com/golang-migrate/migrate/v4/database/pgx"
	"github.com/golang-migrate/migrate/v4/source/iofs"
	"github.com/lib/pq"
	"go.unistack.org/micro/v3/logger"
	"go.unistack.org/unistack-org/pkgdash/config"
	"go.unistack.org/unistack-org/pkgdash/models"
)

const (
	pathMigration = `migrations/postgres`
)

type Postgres struct {
	db *sql.DB
	fs embed.FS
}

func NewStorage(db *sql.DB) (interface{}, error) {
	return &Postgres{db: db}, nil
}

func NewStorageFS(fs embed.FS) func(*sql.DB) (interface{}, error) {
	return func(db *sql.DB) (interface{}, error) {
		return &Postgres{db: db, fs: fs}, nil
	}
}

func (s *Postgres) MigrateUp() error {
	driver, err := mpgx.WithInstance(s.db, &mpgx.Config{
		MigrationsTable: mpgx.DefaultMigrationsTable,
		DatabaseName:    config.ServiceName,
	})
	if err != nil {
		return err
	}
	source, err := iofs.New(s.fs, pathMigration)
	if err != nil {
		return err
	}

	// TODO: pass own logger
	m, err := migrate.NewWithInstance("fs", source, config.ServiceName, driver)
	if err != nil {
		return err
	}

	if err = m.Up(); err != nil && !errors.Is(err, migrate.ErrNoChange) {
		return err
	}

	return nil
}

func (s *Postgres) MigrateDown() error {
	driver, err := mpgx.WithInstance(s.db, &mpgx.Config{
		MigrationsTable: mpgx.DefaultMigrationsTable,
		DatabaseName:    config.ServiceName,
	})
	if err != nil {
		return err
	}
	source, err := iofs.New(s.fs, pathMigration)
	if err != nil {
		return err
	}

	// TODO: pass own logger
	m, err := migrate.NewWithInstance("fs", source, config.ServiceName, driver)
	if err != nil {
		return err
	}

	if err = m.Down(); err != nil && !errors.Is(err, migrate.ErrNoChange) {
		return err
	}

	return nil
}

func (s *Postgres) ListPackage(ctx context.Context) (models.ListPackage, error) {
	rows, err := s.db.QueryContext(ctx, queryListPackage)
	if err != nil {
		return nil, err
	}

	defer func() {
		if err = rows.Close(); err != nil {
			return
		}
		err = rows.Err()
	}()

	result := make([]*models.Package, 0)
	for rows.Next() {
		tmp := &models.Package{}
		if err = rows.Scan(
			&tmp.ID,
			&tmp.Name,
			&tmp.URL,
			pq.Array(&tmp.Comments),
		); err != nil {
			return nil, err
		}
	}

	return result, err
}

func (s *Postgres) AddComment(ctx context.Context, rsp *pb.AddCommentRsp) error {
	tx, err := s.db.BeginTx(ctx, nil)
	if err != nil {
		return err
	}

	defer func() {
		if err != nil {
			if rollbackErr := tx.Rollback(); rollbackErr != nil {
				logger.Errorf(ctx, "AddComment: unable to rollback: %v", rollbackErr)
			}
		} else {
			err = tx.Commit()
		}
	}()

	res, err := tx.ExecContext(ctx, queryAddComment, rsp.Text, rsp.IdPackage)
	if err != nil {
		return err
	}

	if aff, affErr := res.RowsAffected(); err != nil {
		err = affErr
	} else if aff == 0 {
		err = errors.New("rows affected is 0")
	}

	return err
}

func (s *Postgres) AddPackage(ctx context.Context, rsp *pb.AddPackageRsp) error {
	tx, err := s.db.BeginTx(ctx, nil)
	if err != nil {
		return err
	}

	defer func() {
		if err != nil {
			if rollbackErr := tx.Rollback(); rollbackErr != nil {
				logger.Errorf(ctx, "AddPackage: unable to rollback: %v", rollbackErr)
			}
		} else {
			err = tx.Commit()
		}
	}()

	res, err := tx.ExecContext(ctx, queryAddPackage, rsp.Name, rsp.Url, pq.Array(rsp.Modules))
	if err != nil {
		return err
	}

	if aff, affErr := res.RowsAffected(); err != nil {
		err = affErr
	} else if aff == 0 {
		err = errors.New("rows affected is 0")
	}

	return err
}