package goblin

import (
	"fmt"
	"strconv"
	"testing"
)

// So we can test asserting type against its type alias
type String string

// Helper for testing Assertion conditions
type AssertionVerifier struct {
	ShouldPass bool
	didFail    bool
	msg        interface{}
}

func (a *AssertionVerifier) FailFunc(msg interface{}) {
	a.didFail = true
	a.msg = msg
}

func (a *AssertionVerifier) Verify(t *testing.T) {
	if a.didFail == a.ShouldPass {
		t.FailNow()
	}
}

func (a *AssertionVerifier) VerifyMessage(t *testing.T, message string) {
	a.Verify(t)
	if a.msg.(string) != message {
		t.Fatalf(`"%s" != "%s"`, a.msg, message)
	}
}

// Verify that a slice of messages is formatted as expected.
func verifyFormat(t *testing.T, expected string, messages ...interface{}) {
	// Prepend the expected comma if there is at least one message.
	if len(messages) != 0 {
		expected = ", " + expected
	}

	message := formatMessages(messages...)
	if message != expected {
		t.Fatalf(`Message format: "%s" != "%s"`, message, expected)
	}
}

// Test that messages for assertions are formatted as expected.
func TestFormatMessages(t *testing.T) {
	message := "foo bar"

	// No message.
	verifyFormat(t, "")

	// Single message.
	verifyFormat(t, "[]", "")
	verifyFormat(t, "[	]", "	")
	verifyFormat(t, "<nil>", nil)
	verifyFormat(t, message, message)
	verifyFormat(t, message, fmt.Errorf("%s", message))
	num := 12345
	verifyFormat(t, strconv.Itoa(num), num)

	// Multiple messages.
	verifyFormat(t, "[] [ ]", "", " ")
	verifyFormat(t, message+" "+message, message, message)
}

func TestEqual(t *testing.T) {

	verifier := AssertionVerifier{ShouldPass: true}
	a := Assertion{src: 1, fail: verifier.FailFunc}
	a.Equal(1)
	verifier.Verify(t)
	a.Eql(1)
	verifier.Verify(t)

	a = Assertion{src: "foo"}
	a.Equal("foo")
	verifier.Verify(t)
	a.Eql("foo")
	verifier.Verify(t)

	a = Assertion{src: map[string]string{"foo": "bar"}}
	a.Equal(map[string]string{"foo": "bar"})
	verifier.Verify(t)
	a.Eql(map[string]string{"foo": "bar"})
	verifier.Verify(t)

	verifier = AssertionVerifier{ShouldPass: false}
	a = Assertion{src: String("baz"), fail: verifier.FailFunc}
	a.Equal("baz")
	verifier.Verify(t)
	a.Eql("baz")
	verifier.Verify(t)
}

// Test Equal() outputs the correct message upon failure.
func TestEqualWithMessage(t *testing.T) {
	verifier := AssertionVerifier{ShouldPass: false}
	a := Assertion{src: 1, fail: verifier.FailFunc}
	msg := "foo is not bar"
	a.Equal(0, msg)
	verifier.VerifyMessage(t, "1 does not equal 0, "+msg)
}

func TestIsTrue(t *testing.T) {
	verifier := AssertionVerifier{ShouldPass: true}
	a := Assertion{src: true, fail: verifier.FailFunc}
	a.IsTrue()
	verifier.Verify(t)

	verifier = AssertionVerifier{ShouldPass: false}
	a = Assertion{src: false, fail: verifier.FailFunc}
	a.IsTrue()
	verifier.Verify(t)
}

func TestIsFalse(t *testing.T) {
	verifier := AssertionVerifier{ShouldPass: true}
	a := Assertion{src: false, fail: verifier.FailFunc}
	a.IsFalse()
	verifier.Verify(t)

	verifier = AssertionVerifier{ShouldPass: false}
	a = Assertion{src: true, fail: verifier.FailFunc}
	a.IsFalse()
	verifier.Verify(t)
}

func TestIsFalseWithMessage(t *testing.T) {
	verifier := AssertionVerifier{ShouldPass: false}
	a := Assertion{src: true, fail: verifier.FailFunc}
	a.IsFalse("false is not true")
	verifier.Verify(t)
	verifier.VerifyMessage(t, "true expected true to be falsey, false is not true")
}

func TestIsTrueWithMessage(t *testing.T) {
	verifier := AssertionVerifier{ShouldPass: false}
	a := Assertion{src: false, fail: verifier.FailFunc}
	a.IsTrue("true is not false")
	verifier.Verify(t)
	verifier.VerifyMessage(t, "false expected false to be truthy, true is not false")
}