package chislog

import (
	"net"
	"net/http"
)

type Filter func(r *http.Request) bool

type IPExtractor func(r *http.Request) string

type config struct {
	filters     []Filter
	ipExtractor IPExtractor
}

type Option func(cfg *config)

func newConfig(opts ...Option) *config {
	cfg := &config{
		ipExtractor: defaultIPExtractor,
	}

	for _, opt := range opts {
		opt(cfg)
	}

	return cfg
}

// WithFilter adds a filter to the list of filters used by the middleware.
// If any filter indicates to exclude a request then the request will not be logged.
// All filters must allow a request to be logged.
// If no filters are provided, then all requests are logged.
func WithFilter(f Filter) Option {
	return func(c *config) {
		c.filters = append(c.filters, f)
	}
}

// WithIPExtractor takes a function that will be called on every
// request and the returned ip will be added to the log entry.
//
// http.Request RemoteAddr is logged by default.
func WithIPExtractor(extractor IPExtractor) Option {
	return func(c *config) {
		c.ipExtractor = extractor
	}
}

func defaultIPExtractor(r *http.Request) string {
	ip, _, _ := net.SplitHostPort(r.RemoteAddr)
	return ip
}