package httpserver

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

	"github.com/gofiber/fiber/v2"

	"anchorage/internal/pkg/metrics"
)

// accessLog is a minimal, slog-friendly request logger that also feeds
// the Prometheus HTTP request counter. Full structured logging with
// tenant + user attribution lives in the auth middleware once a JWT
// is validated.
//
// /metrics itself is skipped — self-observing scrapes would show up as
// a ton of 200s that tell the operator nothing.
func accessLog() fiber.Handler {
	return func(c *fiber.Ctx) error {
		start := time.Now()
		err := c.Next()
		dur := time.Since(start)

		status := c.Response().StatusCode()
		lvl := slog.LevelInfo
		if status >= http.StatusInternalServerError {
			lvl = slog.LevelError
		} else if status >= http.StatusBadRequest {
			lvl = slog.LevelWarn
		}

		slog.Log(c.UserContext(), lvl, "http",
			"method", c.Method(),
			"path", c.Path(),
			"status", status,
			"duration_ms", dur.Milliseconds(),
			"request_id", c.Get(fiber.HeaderXRequestID),
			"remote", c.IP())

		if c.Path() != "/metrics" {
			metrics.HTTPRequests.
				WithLabelValues(c.Method(), metrics.StatusClass(status)).
				Inc()
		}
		return err
	}
}