package config

import (
	"net/netip"
	"runtime"
	"slices"
	"testing"
)

func TestNewReadsPort(t *testing.T) {
	tests := map[string]int{
		"":      defaultPort,
		"1":     1,
		"9090":  9090,
		"65535": 65535,
	}

	for value, want := range tests {
		t.Run(value, func(t *testing.T) {
			t.Setenv("PORT", value)
			t.Setenv("XDG_DATA_HOME", "")

			cfg, err := New()
			if err != nil {
				t.Fatalf("New() with PORT=%q: %v", value, err)
			}

			if cfg.Port != want {
				t.Errorf("New() with PORT=%q: Port = %d, want %d", value, cfg.Port, want)
			}
		})
	}
}

func TestNewRefusesInvalidPort(t *testing.T) {
	for _, value := range []string{"0", "65536", "-1", "+9090", "http", "80.5"} {
		t.Run(value, func(t *testing.T) {
			t.Setenv("PORT", value)
			t.Setenv("XDG_DATA_HOME", "")

			_, err := New()
			if err == nil {
				t.Errorf("New() with PORT=%q returned no error", value)
			}
		})
	}
}

func TestNewReadsTrustedProxies(t *testing.T) {
	t.Setenv("PORT", "")
	t.Setenv("XDG_DATA_HOME", "")

	t.Setenv("TRUSTED_PROXIES", "")

	cfg, err := New()
	if err != nil {
		t.Fatalf("New() without TRUSTED_PROXIES: %v", err)
	}

	if len(cfg.TrustedProxies) != 0 {
		t.Errorf("New() without TRUSTED_PROXIES: TrustedProxies = %v, want none",
			cfg.TrustedProxies)
	}

	t.Setenv("TRUSTED_PROXIES", "10.0.0.0/8, 192.0.2.1,2001:db8::/32")

	cfg, err = New()
	if err != nil {
		t.Fatalf("New() with TRUSTED_PROXIES: %v", err)
	}

	want := []netip.Prefix{
		netip.MustParsePrefix("10.0.0.0/8"),
		netip.MustParsePrefix("192.0.2.1/32"),
		netip.MustParsePrefix("2001:db8::/32"),
	}
	if !slices.Equal(cfg.TrustedProxies, want) {
		t.Errorf("TrustedProxies = %v, want %v", cfg.TrustedProxies, want)
	}
}

func TestNewRefusesInvalidTrustedProxies(t *testing.T) {
	invalid := []string{"proxy.example", "10.0.0.0/33", "192.0.2.1:80", "192.0.2.1,"}
	for _, value := range invalid {
		t.Run(value, func(t *testing.T) {
			t.Setenv("PORT", "")
			t.Setenv("XDG_DATA_HOME", "")
			t.Setenv("TRUSTED_PROXIES", value)

			_, err := New()
			if err == nil {
				t.Errorf("New() with TRUSTED_PROXIES=%q returned no error", value)
			}
		})
	}
}

func TestNewRefusesRelativeXDGDataHome(t *testing.T) {
	if runtime.GOOS == "darwin" {
		t.Skip("macOS does not read XDG_DATA_HOME")
	}

	t.Setenv("PORT", "")

	t.Setenv("XDG_DATA_HOME", "relative/path")

	_, err := New()
	if err == nil {
		t.Error("New() with a relative XDG_DATA_HOME returned no error")
	}

	t.Setenv("XDG_DATA_HOME", "/var/lib")

	_, err = New()
	if err != nil {
		t.Errorf("New() with XDG_DATA_HOME=/var/lib: %v", err)
	}
}