package main

import (
	"database/sql"
	"time"

	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/config"
	_ "github.com/microsoft/go-mssqldb"
	log "github.com/sirupsen/logrus"
)

func main() {
	log.SetFormatter(&log.TextFormatter{
		FullTimestamp:   true,
		TimestampFormat: time.StampMilli,
	})
	log.SetLevel(log.DebugLevel)

	db, err := sql.Open("sqlserver", config.App.SourceDbUrl)
	if err != nil {
		log.Fatal("Unexpected error connecting to mssql", err)
	}

	log.Debug(config.App.SourceDbUrl)

	if err := db.Ping(); err != nil {
		log.Fatal("Couldn't ping mssql db", err)
	}

	schema := "Cartografia"
	table := "MANZANA"

	columns, err := getTableMetadata(db, schema, table)
	if err != nil {
		log.Fatal("Unexpected error extracting table info", err)
	}

	log.Info("Table info:")

	for _, c := range columns {
		log.Infof("%+v", c)
	}
}

type ColumnInfo struct {
	Name           string
	UserDataType   string
	SystemDataType string
	MaxLength      int16
	Precision      uint8
	Scale          uint8
	Nullable       bool
	IsIdentity     bool
}

func getTableMetadata(db *sql.DB, schema, table string) ([]ColumnInfo, error) {
	query := `
SELECT 
	c.name AS column_name,
	t.name AS user_type_name,
	CASE WHEN t.is_user_defined = 0 THEN t.name ELSE bt.name END AS system_type_name,
	c.max_length AS max_length,
	c.precision AS precision,
	c.scale AS scale,
	c.is_nullable AS is_nullable,
	c.is_identity AS is_identity
FROM sys.columns c
JOIN sys.types t ON c.user_type_id = t.user_type_id
LEFT JOIN sys.types bt ON t.is_user_defined = 1 AND bt.user_type_id = t.system_type_id
JOIN sys.tables st ON c.object_id = st.object_id
JOIN sys.schemas s ON st.schema_id = s.schema_id
WHERE s.name = @schema AND st.name = @table
ORDER BY c.column_id;`

	rows, err := db.Query(query, sql.Named("schema", schema), sql.Named("table", table))
	if err != nil {
		log.Warn(err)

		return nil, err
	}
	defer rows.Close()

	var columns []ColumnInfo
	for rows.Next() {
		var c ColumnInfo
		err := rows.Scan(
			&c.Name,
			&c.UserDataType,
			&c.SystemDataType,
			&c.MaxLength,
			&c.Precision,
			&c.Scale,
			&c.Nullable,
			&c.IsIdentity,
		)

		if err != nil {
			log.Warn(err)

			return nil, err
		}

		columns = append(columns, c)
	}

	return columns, nil
}