package schema

import (
	_ "embed"
	"strings"

	"github.com/jinzhu/inflection"
	"github.com/jmoiron/sqlx"
	_ "github.com/mattn/go-sqlite3"

	"git.offline-twitter.com/offline-labs/gas-stack/pkg/textutils"
)

//go:embed views.sql
var create_views string

// InitDB creates an in-memory DB from a given schema string.
func InitDB(sql_schema string) *sqlx.DB {
	db := sqlx.MustOpen("sqlite3", ":memory:")
	db.MustExec(sql_schema)
	db.MustExec(create_views)
	return db
}

// SchemaFromDB takes a DB connection, checks its schema metadata tables, and returns a Schema.
func SchemaFromDB(db *sqlx.DB) Schema {
	ret := Schema{Tables: map[string]Table{}, Indexes: map[string]Index{}}

	var tables []Table
	err := db.Select(&tables, `select name, is_strict, is_without_rowid from tables`)
	if err != nil {
		panic(err)
	}
	for _, tbl := range tables {
		tbl.TypeName = textutils.SnakeToCamel(inflection.Singular(tbl.TableName))
		tbl.TypeIDName = tbl.TypeName + "ID"
		tbl.VarName = strings.ToLower(string(tbl.TableName[0]))

		err = db.Select(&tbl.Columns, `select * from columns where table_name = ?`, tbl.TableName)
		if err != nil {
			panic(err)
		}
		ret.Tables[tbl.TableName] = tbl
	}

	var indexes []Index
	err = db.Select(&indexes, `select index_name, table_name, is_unique from indexes`)
	if err != nil {
		panic(err)
	}
	for _, idx := range indexes {
		err = db.Select(&idx.Columns, `select column_name from index_columns where index_name = ? order by rank`, idx.Name)
		if err != nil {
			panic(err)
		}
		ret.Indexes[idx.Name] = idx
	}
	return ret
}