package middleware

import (
	"context"
	"log/slog"
	"net/http"
	"time"

	"ruben/inventory2/internal/server/response"
)

func LogRequests(ctx context.Context, logger *slog.Logger) response.Middleware {
	reqIDCh := newRequestIDProvider(ctx)

	return func(fn response.HandlerFunc) response.HandlerFunc {
		return func(r *http.Request) (response.Response, error) {
			start := time.Now()

			args := []any{
				"id", <-reqIDCh,
				"url", r.URL,
			}

			logger.Debug("Request", args...)

			res, err := fn(r)
			end := time.Now()

			var status int
			if err != nil {
				status = response.GetStatusFromError(err)
			} else {
				var ok bool
				if status, ok = res.GetStatus(); !ok {
					status = http.StatusOK
				}
			}

			args = append(args,
				"status", status,
				"elapsed", time.Duration(end.UnixNano()-start.UnixNano()),
			)

			switch status / 100 {
			case 1:
				logger.Debug("Response", args...)
			case 2:
				logger.Debug("Response", args...)
			case 3:
				logger.Debug("Response", args...)
			case 4:
				logger.Warn("Response", args...)
			default:
				logger.Error("Response", args...)
			}

			return res, err
		}
	}
}

func newRequestIDProvider(ctx context.Context) <-chan int {
	reqIDCh := make(chan int)

	go func() {
		defer close(reqIDCh)

		nextReqID := 1

		for {
			select {
			case reqIDCh <- nextReqID:
				nextReqID += 1
			case <-ctx.Done():
				return
			}
		}
	}()

	return reqIDCh
}