package database

import (
	"context"
	"errors"
	"log/slog"
	"time"

	"gorm.io/gorm"
	gormlogger "gorm.io/gorm/logger"
)

type structuredGORMLogger struct {
	logger        *slog.Logger
	level         gormlogger.LogLevel
	slowThreshold time.Duration
}

func newStructuredGORMLogger(logger *slog.Logger) gormlogger.Interface {
	return structuredGORMLogger{logger: logger, level: gormlogger.Warn, slowThreshold: 500 * time.Millisecond}
}

func (l structuredGORMLogger) LogMode(level gormlogger.LogLevel) gormlogger.Interface {
	l.level = level
	return l
}

func (l structuredGORMLogger) Info(_ context.Context, message string, args ...any) {
	if l.level >= gormlogger.Info {
		l.logger.Info("gorm", "message", message, "args", args)
	}
}

func (l structuredGORMLogger) Warn(_ context.Context, message string, args ...any) {
	if l.level >= gormlogger.Warn {
		l.logger.Warn("gorm", "message", message, "args", args)
	}
}

func (l structuredGORMLogger) Error(_ context.Context, message string, args ...any) {
	if l.level >= gormlogger.Error {
		l.logger.Error("gorm", "message", message, "args", args)
	}
}

func (l structuredGORMLogger) Trace(_ context.Context, begin time.Time, query func() (sql string, rowsAffected int64), err error) {
	elapsed := time.Since(begin)
	if err != nil && !errors.Is(err, gorm.ErrRecordNotFound) && l.level >= gormlogger.Error {
		_, rows := query()
		l.logger.Error("database query failed", "error", err, "rows", rows, "duration_ms", elapsed.Milliseconds())
		return
	}
	if elapsed > l.slowThreshold && l.level >= gormlogger.Warn {
		_, rows := query()
		l.logger.Warn("slow database query", "rows", rows, "duration_ms", elapsed.Milliseconds())
	}
}