package buffer

import "testing"

func TestFindMovesForwards(t *testing.T) {
	b := NewFromString("func one()\nfunc two()\nfunc three()")

	found, ok := b.Find("func", Position{Line: 0, Col: 1}, true)

	if !ok {
		t.Fatal("Find() = false, want a match")
	}
	if found.Start != (Position{Line: 1, Col: 0}) {
		t.Errorf("the match starts at %+v, want line 1", found.Start)
	}
	if found.End != (Position{Line: 1, Col: 4}) {
		t.Errorf("the match ends at %+v, want column 4", found.End)
	}
}

func TestFindWrapsRoundToTheStart(t *testing.T) {
	b := NewFromString("needle\nhaystack")

	found, ok := b.Find("needle", Position{Line: 1, Col: 3}, true)

	if !ok {
		t.Fatal("Find() = false, want the search to wrap round")
	}
	if found.Start != (Position{}) {
		t.Errorf("the match starts at %+v, want the top of the buffer", found.Start)
	}
}

func TestFindIsCaseInsensitiveOnRequest(t *testing.T) {
	b := NewFromString("Package Main")

	if _, ok := b.Find("package", Position{}, true); ok {
		t.Error("a case-sensitive search matched a different case")
	}
	found, ok := b.Find("package", Position{}, false)
	if !ok {
		t.Fatal("a case-insensitive search found nothing")
	}
	if found.Start != (Position{}) {
		t.Errorf("the match starts at %+v", found.Start)
	}
}

func TestFindColumnsAreCountedInRunes(t *testing.T) {
	b := NewFromString("héllo wörld")

	found, ok := b.Find("wörld", Position{}, true)

	if !ok {
		t.Fatal("Find() = false")
	}
	if found.Start.Col != 6 {
		t.Errorf("the match starts at column %d, want 6 counted in runes", found.Start.Col)
	}
	if found.End.Col != 11 {
		t.Errorf("the match ends at column %d, want 11", found.End.Col)
	}
}

func TestFindNothing(t *testing.T) {
	b := NewFromString("abc")

	if _, ok := b.Find("xyz", Position{}, true); ok {
		t.Error("Find() = true for a needle that is not there")
	}
	if _, ok := b.Find("", Position{}, true); ok {
		t.Error("Find() = true for an empty needle")
	}
	if _, ok := b.FindPrevious("", Position{}, true); ok {
		t.Error("FindPrevious() = true for an empty needle")
	}
}

func TestFindPreviousMovesBackwards(t *testing.T) {
	b := NewFromString("func one()\nfunc two()\nfunc three()")

	found, ok := b.FindPrevious("func", Position{Line: 2, Col: 0}, true)

	if !ok {
		t.Fatal("FindPrevious() = false, want a match")
	}
	if found.Start != (Position{Line: 1, Col: 0}) {
		t.Errorf("the match starts at %+v, want line 1", found.Start)
	}
}

func TestFindPreviousWrapsRoundToTheEnd(t *testing.T) {
	b := NewFromString("first\nlast target")

	found, ok := b.FindPrevious("target", Position{}, true)

	if !ok {
		t.Fatal("FindPrevious() = false, want the search to wrap round")
	}
	if found.Start.Line != 1 {
		t.Errorf("the match is on line %d, want the last line", found.Start.Line)
	}
}

func TestFindPreviousPicksTheLastMatchOnALine(t *testing.T) {
	b := NewFromString("x x x")

	found, ok := b.FindPrevious("x", Position{Line: 0, Col: 5}, true)

	if !ok {
		t.Fatal("FindPrevious() = false")
	}
	if found.Start.Col != 4 {
		t.Errorf("the match is at column %d, want the last one before the cursor", found.Start.Col)
	}
}

func TestFindFromAPositionPastTheEndOfALine(t *testing.T) {
	b := NewFromString("ab\ntarget")

	found, ok := b.Find("target", Position{Line: 0, Col: 99}, true)

	if !ok {
		t.Fatal("Find() = false")
	}
	if found.Start.Line != 1 {
		t.Errorf("the match is on line %d, want line 1", found.Start.Line)
	}
}