//go:build ignore

package main

import (
	"database/sql"
	"encoding/json"
	"os"
	"sort"
	"strings"
	"time"

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

type metadataRecord struct {
	VIN                string     `json:"vin"`
	Plate              string     `json:"plate"`
	Brand              string     `json:"brand"`
	Model              string     `json:"model"`
	VehicleModelID     int64      `json:"vehicle_model_id"`
	BatteryCapacityKWh float64    `json:"battery_capacity_kwh"`
	TankCapacityL      float64    `json:"tank_capacity_l"`
	SourceUpdatedAt    *time.Time `json:"source_updated_at,omitempty"`
}

func main() {
	if len(os.Args) != 2 {
		panic("usage: query_metadata <output.json>")
	}
	dsn := strings.TrimSpace(os.Getenv("MYSQL_DSN"))
	if dsn == "" {
		panic("MYSQL_DSN is required")
	}
	db, err := sql.Open("mysql", dsn)
	if err != nil {
		panic(err)
	}
	defer db.Close()
	rows, err := db.Query(`SELECT UPPER(TRIM(vi.vin)),COALESCE(vi.plate_number,''),
COALESCE(vm.brand,''),COALESCE(vm.model,''),vm.id,vm.battery_capacity,vm.tank_capacity,
CASE
  WHEN vi.update_time IS NULL THEN vm.update_time
  WHEN vm.update_time IS NULL THEN vi.update_time
  ELSE GREATEST(vi.update_time,vm.update_time)
END
FROM ln_asset_management.vehicle_info vi
JOIN ln_asset_management.vehicle_model vm ON vm.id=vi.vehicle_model_id
WHERE COALESCE(vi.del_flag,'0')='0' AND COALESCE(vm.del_flag,'0')='0'
  AND LOWER(TRIM(vm.brand))='hyundai'
  AND LENGTH(TRIM(vi.vin))=17
  AND vm.tank_capacity>0
  AND vm.battery_capacity>0
ORDER BY vi.vin,vi.update_time DESC,vi.id DESC`)
	if err != nil {
		panic(err)
	}
	defer rows.Close()
	byVIN := map[string]metadataRecord{}
	for rows.Next() {
		var row metadataRecord
		var updated sql.NullTime
		if err := rows.Scan(&row.VIN, &row.Plate, &row.Brand, &row.Model, &row.VehicleModelID, &row.BatteryCapacityKWh, &row.TankCapacityL, &updated); err != nil {
			panic(err)
		}
		if _, exists := byVIN[row.VIN]; exists {
			continue
		}
		if updated.Valid {
			value := updated.Time
			row.SourceUpdatedAt = &value
		}
		byVIN[row.VIN] = row
	}
	if err := rows.Err(); err != nil {
		panic(err)
	}
	vins := make([]string, 0, len(byVIN))
	for vin := range byVIN {
		vins = append(vins, vin)
	}
	sort.Strings(vins)
	out := make([]metadataRecord, 0, len(vins))
	for _, vin := range vins {
		out = append(out, byVIN[vin])
	}
	output, err := os.Create(os.Args[1])
	if err != nil {
		panic(err)
	}
	defer output.Close()
	encoder := json.NewEncoder(output)
	encoder.SetIndent("", "  ")
	if err := encoder.Encode(out); err != nil {
		panic(err)
	}
}