package db

import (
	"database/sql"
	"fmt"

	_ "modernc.org/sqlite"
)

func openSQLite(c ConnReq) (*sql.DB, error) {
	path := c.Database
	if path == "" {
		path = c.Host
	}
	if path == "" {
		return nil, fmt.Errorf("SQLite 需要 database 填文件路径")
	}
	return sql.Open("sqlite", path)
}

func listDatabasesSQLite(_ *sql.DB) ([]string, error) {
	return []string{"main"}, nil
}

func listTablesSQLite(db *sql.DB, _ string) ([]string, error) {
	rows, err := db.Query(`SELECT name FROM sqlite_master WHERE type='table' AND name NOT LIKE 'sqlite_%' ORDER BY 1`)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	out := []string{}
	for rows.Next() {
		var name string
		if err := rows.Scan(&name); err != nil {
			return nil, err
		}
		out = append(out, name)
	}
	return out, rows.Err()
}

func listColumnsSQLite(dbh *sql.DB, _, table string) ([]ColumnInfo, error) {
	rows, err := dbh.Query(`PRAGMA table_info(` + quotePGIdent(table) + `)`)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	var out []ColumnInfo
	for rows.Next() {
		var cid int
		var name, typ string
		var notnull, pk int
		var def sql.NullString
		if err := rows.Scan(&cid, &name, &typ, &notnull, &def, &pk); err != nil {
			return nil, err
		}
		col := ColumnInfo{Name: name, Type: typ, Nullable: notnull == 0}
		if pk > 0 {
			col.Key = "PRI"
		}
		if def.Valid {
			col.Default = def.String
		}
		out = append(out, col)
	}
	if out == nil {
		out = []ColumnInfo{}
	}
	return out, rows.Err()
}