package config

import (
	"strings"
	"testing"
	"time"
)

func TestParseSize(t *testing.T) {
	cases := map[string]int64{
		"":          Unlimited,
		"0":         Unlimited,
		"unlimited": Unlimited,
		"512":       512,
		"512B":      512,
		"2GiB":      2 << 30,
		"2 GiB":     2 << 30,
		"2G":        2 << 30,
		"500MB":     500_000_000,
		"1.5MiB":    1572864,
		"2gib":      2 << 30,
	}
	for in, want := range cases {
		got, err := ParseSize(in)
		if err != nil {
			t.Errorf("ParseSize(%q): %v", in, err)
			continue
		}
		if got != want {
			t.Errorf("ParseSize(%q) = %d, want %d", in, got, want)
		}
	}
	for _, in := range []string{"-1", "lots", "2XiB", "GiB2"} {
		if _, err := ParseSize(in); err == nil {
			t.Errorf("ParseSize(%q) accepted an invalid size", in)
		}
	}
}

func TestParseDuration(t *testing.T) {
	cases := map[string]time.Duration{
		"":      Unlimited,
		"never": Unlimited,
		"0":     Unlimited,
		"90m":   90 * time.Minute,
		"72h":   72 * time.Hour,
		"3d":    72 * time.Hour,
		"1w":    168 * time.Hour,
		"1.5d":  36 * time.Hour,
	}
	for in, want := range cases {
		got, err := ParseDuration(in)
		if err != nil {
			t.Errorf("ParseDuration(%q): %v", in, err)
			continue
		}
		if got != want {
			t.Errorf("ParseDuration(%q) = %s, want %s", in, got, want)
		}
	}
	for _, in := range []string{"-3d", "soon", "3days"} {
		if _, err := ParseDuration(in); err == nil {
			t.Errorf("ParseDuration(%q) accepted an invalid duration", in)
		}
	}
}

// The formatters are human-facing and round to two decimals, so they only
// round-trip exactly for values that land on a unit boundary. Nothing in the
// program re-parses their output; this pins the cases that are shown most.
func TestFormatRoundTrips(t *testing.T) {
	for _, n := range []int64{0, 512, 2 << 30, 100 << 20, 1536} {
		if got, err := ParseSize(FormatSize(n)); err != nil || got != n {
			t.Errorf("FormatSize(%d) = %q, which parses back to %d (%v)", n, FormatSize(n), got, err)
		}
	}
	for _, d := range []time.Duration{0, time.Hour, 72 * time.Hour, 90 * time.Minute} {
		if got, err := ParseDuration(FormatDuration(d)); err != nil || got != d {
			t.Errorf("FormatDuration(%s) = %q, which parses back to %s (%v)", d, FormatDuration(d), got, err)
		}
		// FormatLifetime is shown next to the field a caller types into, so
		// what it prints has to be something ParseDuration would accept.
		if got, err := ParseDuration(FormatLifetime(d)); err != nil || got != d {
			t.Errorf("FormatLifetime(%s) = %q, which parses back to %s (%v)", d, FormatLifetime(d), got, err)
		}
	}
	if got := FormatLifetime(Unlimited); got != "unlimited" {
		t.Errorf("FormatLifetime(Unlimited) = %q, want %q", got, "unlimited")
	}
}

// The spellings themselves, not just their round trip: Duration.String() pads
// out the units below the largest one, and trimming that tail is easy to get
// wrong in a way that eats a real digit ("1m30s" must not become "1m3").
func TestFormatDurationSpelling(t *testing.T) {
	for _, c := range []struct {
		in   time.Duration
		want string
	}{
		{Unlimited, "never"},
		{30 * time.Second, "30s"},
		{time.Minute, "1m"},
		{90 * time.Second, "1m30s"},
		{90 * time.Minute, "1h30m"},
		{2 * time.Hour, "2h"},
		{25 * time.Hour, "25h"},
		{72 * time.Hour, "3d"},
	} {
		if got := FormatDuration(c.in); got != c.want {
			t.Errorf("FormatDuration(%s) = %q, want %q", c.in, got, c.want)
		}
	}
}

// A word the parser does not expect has to be refused, not ignored: the flag
// package stops at the first non-flag argument, so a command that accepted one
// would silently drop every option after it - including the one naming the
// file it writes.
func TestParseRefusesStrayArguments(t *testing.T) {
	newSet := func() (*Set, *string, *bool) {
		var listen string
		var flagged bool
		s := NewSet("test", "UNCENSORED_SEND_TEST_")
		s.String(&listen, "listen", "l", "default", "ADDR", "listen address")
		s.Bool(&flagged, "vanity", "", false, "a boolean")
		return s, &listen, &flagged
	}

	for _, args := range [][]string{
		{"--vanity", "false"},               // the value a boolean never takes
		{"stray"},                           // a word on its own
		{"--vanity", "false", "-l", "here"}, // options after the stray word
	} {
		s, listen, _ := newSet()
		err := s.Parse(args)
		if err == nil {
			t.Errorf("Parse(%q) was accepted; listen = %q", args, *listen)
			continue
		}
		if !strings.Contains(err.Error(), "unexpected argument") {
			t.Errorf("Parse(%q) failed with %v, which does not name the problem", args, err)
		}
	}

	// The forms that are actually correct still parse.
	for _, args := range [][]string{
		{"--vanity=false"},
		{"--vanity", "-l", "here"},
		{"-l", "here"},
		{},
	} {
		s, _, _ := newSet()
		if err := s.Parse(args); err != nil {
			t.Errorf("Parse(%q) = %v, want it accepted", args, err)
		}
	}
}

// The convention is: one hyphen for a letter, two for a word. It is enforced
// here because the stdlib flag package treats both forms as the same.
func TestHyphenConvention(t *testing.T) {
	newSet := func() (*Set, *string) {
		var listen string
		s := NewSet("test", "UNCENSORED_SEND_TEST_")
		s.String(&listen, "listen", "l", "default", "ADDR", "listen address")
		return s, &listen
	}

	for _, args := range [][]string{{"--listen", "x"}, {"-l", "x"}, {"--listen=x"}, {"-l=x"}} {
		s, listen := newSet()
		if err := s.Parse(args); err != nil {
			t.Errorf("%v: %v", args, err)
			continue
		}
		if *listen != "x" {
			t.Errorf("%v: listen = %q", args, *listen)
		}
	}

	for _, args := range [][]string{{"-listen", "x"}, {"--l", "x"}, {"-listen=x"}} {
		s, _ := newSet()
		err := s.Parse(args)
		if err == nil {
			t.Errorf("%v was accepted; it breaks the hyphen convention", args)
			continue
		}
		if !strings.Contains(err.Error(), "hyphen") {
			t.Errorf("%v: error does not explain the convention: %v", args, err)
		}
	}
}

func TestEnvFallback(t *testing.T) {
	t.Setenv("UNCENSORED_SEND_TEST_MAX_SIZE", "4GiB")
	var size int64
	s := NewSet("test", "UNCENSORED_SEND_TEST_")
	s.Size(&size, "max-size", "s", "2GiB", "cap")
	if err := s.Parse(nil); err != nil {
		t.Fatal(err)
	}
	if size != 4<<30 {
		t.Errorf("size = %d, want 4GiB from the environment", size)
	}

	// An explicit flag still wins over the environment.
	s = NewSet("test", "UNCENSORED_SEND_TEST_")
	s.Size(&size, "max-size", "s", "2GiB", "cap")
	if err := s.Parse([]string{"--max-size", "1GiB"}); err != nil {
		t.Fatal(err)
	}
	if size != 1<<30 {
		t.Errorf("size = %d, want the flag to win", size)
	}
}

func TestNormalisePath(t *testing.T) {
	cases := map[string]string{
		"":       "/",
		"/":      "/",
		"send":   "/send/",
		"/send":  "/send/",
		"/send/": "/send/",
		"a/b":    "/a/b/",
	}
	for in, want := range cases {
		if got := NormalisePath(in); got != want {
			t.Errorf("NormalisePath(%q) = %q, want %q", in, got, want)
		}
	}
}

func TestDefaultExpiryMustFitWithinMax(t *testing.T) {
	c := &Config{BasePath: "/", DataDir: "d", SweepInterval: time.Minute, MaxConcurrent: 1,
		MaxExpiry: time.Hour, DefaultExpiry: 24 * time.Hour}
	if err := c.Normalise(); err == nil {
		t.Error("a default longer than the maximum was accepted")
	}
	c.DefaultExpiry = Unlimited
	if err := c.Normalise(); err == nil {
		t.Error("an unlimited default under a finite maximum was accepted")
	}
}

func TestPortOverridesListen(t *testing.T) {
	cases := []struct {
		listen string
		port   int
		want   string
	}{
		{"127.0.0.1:8080", 0, "127.0.0.1:8080"},
		{"127.0.0.1:8080", 9000, "127.0.0.1:9000"},
		{"0.0.0.0:8080", 3000, "0.0.0.0:3000"},
		{"localhost", 3000, "localhost:3000"}, // a bare host is fine with --port
		{"[::1]:8080", 3000, "[::1]:3000"},
	}
	for _, c := range cases {
		cfg := &Config{
			Listen: c.listen, Port: c.port, BasePath: "/", DataDir: "d",
			SweepInterval: time.Minute, MaxConcurrent: 1,
		}
		if err := cfg.Normalise(); err != nil {
			t.Errorf("listen %q port %d: %v", c.listen, c.port, err)
			continue
		}
		if cfg.Listen != c.want {
			t.Errorf("listen %q port %d => %q, want %q", c.listen, c.port, cfg.Listen, c.want)
		}
	}

	for _, c := range []struct {
		listen string
		port   int
	}{{"127.0.0.1:8080", 70000}, {"127.0.0.1:8080", -1}, {"localhost", 0}} {
		cfg := &Config{
			Listen: c.listen, Port: c.port, BasePath: "/", DataDir: "d",
			SweepInterval: time.Minute, MaxConcurrent: 1,
		}
		if err := cfg.Normalise(); err == nil {
			t.Errorf("listen %q port %d was accepted", c.listen, c.port)
		}
	}
}