// Applies init.sql to the local MySQL using the app's built-in default connection.
package main

import (
	"database/sql"
	"fmt"
	"os"
	"strings"

	_ "github.com/go-sql-driver/mysql"
)

func main() {
	if len(os.Args) > 1 && os.Args[1] == "inspect" {
		inspect()
		return
	}
	raw, err := os.ReadFile("init.sql")
	if err != nil {
		panic(err)
	}
	db, err := sql.Open("mysql", "root:root@tcp(127.0.0.1:3306)/?multiStatements=false&charset=utf8mb4")
	if err != nil {
		panic(err)
	}
	defer db.Close()
	// init.sql 的升级段依赖会话变量（SET @sql / PREPARE），必须固定在同一连接上执行。
	db.SetMaxOpenConns(1)

	var kept []string
	for _, line := range strings.Split(string(raw), "\n") {
		if t := strings.TrimSpace(line); strings.HasPrefix(t, "--") {
			continue
		}
		kept = append(kept, line)
	}
	for _, stmt := range strings.Split(strings.Join(kept, "\n"), ";") {
		s := strings.TrimSpace(stmt)
		if s == "" {
			continue
		}
		if _, err := db.Exec(s); err != nil {
			fmt.Println("ERR:", err, "stmt:", s[:min(80, len(s))])
			os.Exit(1)
		}
	}
	var n int
	if err := db.QueryRow("SELECT COUNT(*) FROM code_count.sync_settings").Scan(&n); err != nil {
		fmt.Println("verify failed:", err)
		os.Exit(1)
	}
	fmt.Println("ok, sync_settings rows:", n)
}

func min(a, b int) int {
	if a < b {
		return a
	}
	return b
}

func inspect() {
	db, err := sql.Open("mysql", "root:root@tcp(127.0.0.1:3306)/code_count?charset=utf8mb4")
	if err != nil {
		panic(err)
	}
	defer db.Close()
	rows, err := db.Query("SELECT user_id, name, LENGTH(value), updated_at FROM sync_settings ORDER BY user_id, name")
	if err != nil {
		panic(err)
	}
	defer rows.Close()
	for rows.Next() {
		var uid int64
		var name, at string
		var n int
		if err := rows.Scan(&uid, &name, &n, &at); err != nil {
			panic(err)
		}
		fmt.Printf("user=%d name=%-12s bytes=%-6d at=%s\n", uid, name, n, at)
	}
}