package database

import (
	"context"
	"errors"
	"time"

	"github.com/rs/zerolog"
	"gorm.io/gorm"
	"gorm.io/gorm/logger"
)

type GormLogger struct {
	logger        zerolog.Logger
	slowThreshold time.Duration
	logLevel      logger.LogLevel
}

func (l *GormLogger) LogMode(level logger.LogLevel) logger.Interface {
	newLogger := *l
	newLogger.logLevel = level
	return &newLogger
}

func (l *GormLogger) Info(ctx context.Context, msg string, data ...interface{}) {
	if l.logLevel >= logger.Info {
		l.logger.Info().Msgf(msg, data...)
	}
}

func (l *GormLogger) Warn(ctx context.Context, msg string, data ...interface{}) {
	if l.logLevel >= logger.Warn {
		l.logger.Warn().Msgf(msg, data...)
	}
}

func (l *GormLogger) Error(ctx context.Context, msg string, data ...interface{}) {
	if l.logLevel >= logger.Error {
		l.logger.Error().Msgf(msg, data...)
	}
}

func (l *GormLogger) Trace(ctx context.Context, begin time.Time, fc func() (string, int64), err error) {
	if l.logLevel <= logger.Silent {
		return
	}

	elapsed := time.Since(begin)
	sql, rows := fc()

	switch {
	// cache miss / record not found - expected, don't log as error
	case err != nil && errors.Is(err, gorm.ErrRecordNotFound):
		if l.logLevel >= logger.Info {
			l.logger.Debug().
				Str("sql", sql).
				Int64("rows", rows).
				Dur("elapsed", elapsed).
				Msg("QueryCacheMiss")
		}
	// error query
	case err != nil && l.logLevel >= logger.Error:
		l.logger.Error().
			Err(err).
			Str("sql", sql).
			Int64("rows", rows).
			Dur("elapsed", elapsed).
			Msg("QueryError")

	// slow query
	case elapsed > l.slowThreshold && l.logLevel >= logger.Warn:
		l.logger.Warn().
			Str("sql", sql).
			Int64("rows", rows).
			Dur("elapsed", elapsed).
			Msg("SlowQuery")

	// normal query
	case l.logLevel >= logger.Info:
		l.logger.Debug().
			Str("sql", sql).
			Int64("rows", rows).
			Dur("elapsed", elapsed).
			Msg("Query")
	}
}

func NewGormLogger(serviceLogger zerolog.Logger, threshold time.Duration) *GormLogger {
	return &GormLogger{
		logger:        serviceLogger.With().Str("module", "gorm").Logger(),
		slowThreshold: threshold,
		logLevel:      logger.Warn, // default
	}
}