package auth

import (
	"regexp"
	"testing"
)

var passPattern *regexp.Regexp = regexp.MustCompile(`^(?:[a-z]{4}-){3}[a-z]{4}$`)

const basicShadow = "jhh:9999:$2a$12$tcv2MrtXgibAJHsSwVfHiOevXBFmiGy0HTNoOB8QzIhEh46iWS1uC:YW55dGhpbmcgbW9yZSB0aGFuIDUgcmVwcyBpcyBjYXJkaW8="
const extraDataShadow = "skw:1:$2a$12$lINQdYWHOcLKoqhNOr3mNOpZSAu5JOBS2F7T/VDfYn2rvv6qUJehG::additional:fields"

func TestEntryFromShadow(t *testing.T) {
	cases := []struct {
		shadow      string
		wantErr     bool
		username    string
		id          uint64
		hash        string
		description string
		rest        []string
	}{
		{
			shadow:   "pfish:1234:$2a$12$apFtWGXKtWBavVy5eo.22Ohs43GudT5IYTqyQkIBX9LpS7YtvKBpa",
			username: "pfish",
			id:       1234,
			hash:     "$2a$12$apFtWGXKtWBavVy5eo.22Ohs43GudT5IYTqyQkIBX9LpS7YtvKBpa",
		},
		{
			shadow:      basicShadow,
			username:    "jhh",
			id:          9999,
			hash:        "$2a$12$tcv2MrtXgibAJHsSwVfHiOevXBFmiGy0HTNoOB8QzIhEh46iWS1uC",
			description: "anything more than 5 reps is cardio",
		},
		{
			shadow:   extraDataShadow,
			username: "skw",
			id:       1,
			hash:     "$2a$12$lINQdYWHOcLKoqhNOr3mNOpZSAu5JOBS2F7T/VDfYn2rvv6qUJehG",
			rest:     []string{"additional", "fields"},
		},
		{
			shadow:  "user:one:bogushash",
			wantErr: true,
		},
		{
			shadow:  "user:-1:bogushash",
			wantErr: true,
		},
		{
			shadow:  "tooshort",
			wantErr: true,
		},
		{
			shadow:  "test:0:bogushash:invalid base64",
			wantErr: true,
		},
	}
	for _, c := range cases {
		entry, err := EntryFromShadow(c.shadow)
		if c.wantErr {
			if err == nil {
				t.Errorf("EntryFromShadow(%q) == _, nil; want non-nil err", c.shadow)
			}
			continue
		}
		if err != nil {
			t.Errorf("EntryFromShadow(%q) == _, %q; want nil err", c.shadow, err)
		}
		if c.username != entry.username {
			t.Errorf("EntryFromShadow(%q).username = %q; want %q", c.shadow, entry.username, c.username)
		}
		if c.hash != string(entry.hash) {
			t.Errorf("EntryFromShadow(%q).password = %q; want %q", c.shadow, entry.hash, c.hash)
		}
		if c.description != entry.description {
			t.Errorf("EntryFromShadow(%q).description = %q; want %q", c.shadow, entry.description, c.description)
		}
		restEqual := false
		if len(c.rest) == len(entry.rest) {
			restEqual = true
			for i := range c.rest {
				if c.rest[i] != entry.rest[i] {
					restEqual = false
					break
				}
			}
		}
		if !restEqual {
			t.Errorf("EntryFromShadow(%q).rest = %q; want %q", c.shadow, entry.rest, c.rest)
		}
	}
}

func TestNewEntry(t *testing.T) {
	cases := []struct {
		username    string
		description string
		wantErr     bool
	}{
		{"pfish", "one", false},
		{"pfish", "the other", false},
		{"with:colons", "", true},
		{"pfish", string(make([]byte, 1000)), true},
	}
	for _, c := range cases {
		entry, password, err := NewEntry(c.username, c.description)
		if c.wantErr {
			if err == nil {
				t.Errorf("NewEntry(%q, %q) = _, _, nil; want non-nil err", c.username, c.description)
			}
			continue
		}
		if err != nil {
			t.Errorf("NewEntry(%q, %q) = _, _, %q; want nil err", c.username, c.description, err)
		}
		if c.username != entry.username {
			t.Errorf("NewEntry(%q, %q).username = %q, want %q",
				c.username, c.description, entry.username, c.username)
		}
		if entry.id == 0 {
			// This test has a 1/(2**64) chance of failing! :o
			t.Errorf("NewEntry(_, _).id == 0, want nonzero")
		}
		if c.description != entry.description {
			t.Errorf("NewEntry(%q, %q).description = %q, want %q",
				c.username, c.description, entry.description, c.description)
		}
		if !passPattern.MatchString(password) {
			t.Errorf("NewEntry(_, _) = _, %q, _; wanted to match xxxx-xxxx-xxxx-xxxx", password)
		}
		if !entry.Authenticate(c.username, password) {
			t.Errorf("NewEntry(%q, %q).Authenticate(%q, %q) failed",
				c.username, c.description, c.username, password)
		}
	}
}

func TestGenPassword(t *testing.T) {
	p := genPassword()
	if !passPattern.MatchString(string(p)) {
		t.Errorf("genPassword() = %q; wanted to match xxxx-xxxx-xxxx-xxxx", p)
	}
}

func TestAuthenticate(t *testing.T) {
	entry, password, err := NewEntry("pfish", "")
	if err != nil {
		t.Errorf("Error building entry")
	}
	type testcase struct {
		username, password string
		want               bool
	}

	cases := []testcase{
		{"pfish", password, true},
		{"jhh", password, false},
		{"pfish", "not the password", false},
		{"jhh", "not the password", false},
	}
	for _, c := range cases {
		got := entry.Authenticate(c.username, c.password)
		if got != c.want {
			t.Errorf("entry.Authenticate(%q, %q) == %q, want %q",
				c.username, c.password, got, c.want)
		}
	}

	entry, err = EntryFromShadow(basicShadow)
	if err != nil {
		t.Errorf("Error loading valid shadow")
	}

	cases = []testcase{
		{"jhh", "nocardio", true},
		{"pfish", "nocardio", false},
		{"jhh", "not the password", false},
		{"pfish", "not the password", false},
	}
	for _, c := range cases {
		got := entry.Authenticate(c.username, c.password)
		if got != c.want {
			t.Errorf("entry.Authenticate(%q, %q) == %q, want %q",
				c.username, c.password, got, c.want)
		}
	}
}

func testMatchesID(t *testing.T) {
	entry, err := EntryFromShadow(basicShadow)
	if err != nil {
		t.Errorf("Error loading valid shadow")
	}
	cases := []struct {
		username string
		id       uint64
		want     bool
	}{
		{"jhh", 1234, true},
		{"pfish", 1234, false},
		{"jhh", 9999, false},
		{"pfish", 9999, false},
	}
	for _, c := range cases {
		got := entry.MatchesID(c.username, c.id)
		if got != c.want {
			t.Errorf("entry.MatchesID(%q, %q) == %q, want %q",
				c.username, c.id, got, c.want)
		}
	}
}

func TestEncode(t *testing.T) {
	// Crafted entry
	shadowed, err := EntryFromShadow(basicShadow)
	if err != nil {
		t.Errorf("Error loading valid shadow")
	}
	extraShadowed, err := EntryFromShadow(extraDataShadow)
	if err != nil {
		t.Errorf("Error loading valid shadow")
	}
	cases := []struct {
		entry *Entry
		want  string
	}{
		{
			&Entry{
				username:    "testuser",
				id:          6775,
				hash:        "bogushash",
				description: "something",
			},
			"testuser:6775:bogushash:c29tZXRoaW5n",
		},
		{
			&Entry{
				username:    "testuser",
				id:          6775,
				hash:        "bogushash",
				description: "something",
				rest:        []string{"a", "B"},
			},
			"testuser:6775:bogushash:c29tZXRoaW5n:a:B",
		},
		{shadowed, basicShadow},
		{extraShadowed, extraDataShadow},
	}
	for _, c := range cases {
		got := string(c.entry.Encode())
		if got != c.want {
			t.Errorf("entry.Encode() = %q, want %q", got, c.want)
		}
	}
}