package tokenize

import (
	"testing"
)

func TestMakeSplitOutput_SplitsOutputAtActiveCursorPosition(t *testing.T) {
	// Create input, accept the first rune.
	tokenAPI := NewAPI("Testing")
	r, _, _ := tokenAPI.Input.Rune.Peek(0)
	tokenAPI.Input.Rune.Accept(r) // T
	AssertEqual(t, "T", tokenAPI.Output.String(), "accepted rune in input")

	// Split
	split := tokenAPI.SplitOutput()
	AssertEqual(t, 1, tokenAPI.pointers.offset, "parent offset")
	AssertEqual(t, 1, tokenAPI.pointers.offset, "child offset")

	// Accept two runes via fork.
	r, _, _ = tokenAPI.Input.Rune.Peek(0)
	tokenAPI.Input.Rune.Accept(r) // e
	r, _, _ = tokenAPI.Input.Rune.Peek(0)
	tokenAPI.Input.Rune.Accept(r) // s
	AssertEqual(t, "es", tokenAPI.Output.String(), "result runes in split output")
	AssertEqual(t, 3, tokenAPI.pointers.offset, "offset in split output")

	// Merge split output back into main output.
	tokenAPI.MergeSplitOutput(split)
	AssertEqual(t, "Tes", tokenAPI.Output.String(), "result runes in parent Input after Merge()")
	AssertEqual(t, 3, tokenAPI.pointers.offset, "parent offset")
}

// func TestGivenForkedChildWhichAcceptedRune_AfterMerging_RuneEndsUpInParentResult(t *testing.T) {
// 	tokenAPI := NewAPI("Testing")
// 	r, _, _ := tokenAPI.Input.Rune.Peek(0)
// 	tokenAPI.Input.Rune.Accept(r) // T

// 	f1 := tokenAPI.Fork()
// 	r, _, _ = tokenAPI.Input.Rune.Peek(0)
// 	tokenAPI.Input.Rune.Accept(r) // e

// 	f2 := tokenAPI.Fork()
// 	r, _, _ = tokenAPI.Input.Rune.Peek(0)
// 	tokenAPI.Input.Rune.Accept(r) // s
// 	AssertEqual(t, "s", tokenAPI.Output.String(), "f2 String()")
// 	AssertEqual(t, 3, tokenAPI.stackFrame.offset, "f2.offset A")

// 	tokenAPI.Merge(f2)
// 	tokenAPI.Dispose(f2)
// 	AssertEqual(t, "es", tokenAPI.Output.String(), "f1 String()")
// 	AssertEqual(t, 3, tokenAPI.stackFrame.offset, "f1.offset A")

// 	tokenAPI.Merge(f1)
// 	tokenAPI.Dispose(f1)
// 	AssertEqual(t, "Tes", tokenAPI.Output.String(), "top-level API String()")
// 	AssertEqual(t, 3, tokenAPI.stackFrame.offset, "f1.offset A")
// }

// func TestFlushInput(t *testing.T) {
// 	tokenAPI := NewAPI("cool")

// 	// Flushing without any read data is okay. FlushInput() will return
// 	// false in this case, and nothing else happens.
// 	AssertTrue(t, tokenAPI.Input.Flush() == false, "flush input at start")

// 	r, _, _ := tokenAPI.Input.Rune.Peek(0)
// 	tokenAPI.Input.Rune.Accept(r) // c
// 	r, _, _ = tokenAPI.Input.Rune.Peek(0)
// 	tokenAPI.Input.Rune.Accept(r) // o

// 	AssertTrue(t, tokenAPI.Input.Flush() == true, "flush input after reading some data")
// 	AssertEqual(t, 0, tokenAPI.stackFrame.offset, "offset after flush input")

// 	AssertTrue(t, tokenAPI.Input.Flush() == false, "flush input after flush input")

// 	// Read offset is now zero, but reading should continue after "co".
// 	// The output so far  isn't modified, so the following accept calls
// 	// will add their runes to the already accepted string "co".
// 	r, _, _ = tokenAPI.Input.Rune.Peek(0)
// 	tokenAPI.Input.Rune.Accept(r) // o
// 	r, _, _ = tokenAPI.Input.Rune.Peek(0)
// 	tokenAPI.Input.Rune.Accept(r) // o

// 	AssertEqual(t, "cool", tokenAPI.Output.String(), "end result")
// }

// func TestInputFlusherWrapper(t *testing.T) {
// 	runeA := A.Rune('a')
// 	flushB := C.FlushInput(A.Rune('b'))
// 	tokenAPI := NewAPI("abaab")
// 	runeA(tokenAPI)
// 	AssertEqual(t, 1, tokenAPI.stackFrame.offset, "offset after 1 read")
// 	AssertEqual(t, "a", tokenAPI.Output.String(), "runes after 1 read")
// 	flushB(tokenAPI)
// 	AssertEqual(t, 0, tokenAPI.stackFrame.offset, "offset after 2 reads + input flush")
// 	AssertEqual(t, "ab", tokenAPI.Output.String(), "runes after 2 reads")
// 	runeA(tokenAPI)
// 	AssertEqual(t, 1, tokenAPI.stackFrame.offset, "offset after 3 reads")
// 	AssertEqual(t, "aba", tokenAPI.Output.String(), "runes after 3 reads")
// 	runeA(tokenAPI)
// 	AssertEqual(t, 2, tokenAPI.stackFrame.offset, "offset after 4 reads")
// 	AssertEqual(t, "abaa", tokenAPI.Output.String(), "runes after 4 reads")
// 	flushB(tokenAPI)
// 	AssertEqual(t, 0, tokenAPI.stackFrame.offset, "offset after 5 reads + input flush")
// 	AssertEqual(t, "abaab", tokenAPI.Output.String(), "runes after 5 reads")
// }

func AssertEqual(t *testing.T, expected interface{}, actual interface{}, forWhat string) {
	if expected != actual {
		t.Errorf(
			"Unexpected value for %s:\nexpected: %q\nactual: %q",
			forWhat, expected, actual)
	}
}

func AssertTrue(t *testing.T, b bool, assertion string) {
	if !b {
		t.Errorf("Assertion %s is false", assertion)
	}
}