package app

import (
	"os"
	"path/filepath"
	"strings"
	"testing"

	"github.com/gdamore/tcell/v2"
)

// newTreeApp returns an editor whose working directory is a small project.
func newTreeApp(t *testing.T, names ...string) (*App, tcell.SimulationScreen, string) {
	t.Helper()

	root := testDirectory(t, names...)
	t.Chdir(root)

	a, screen := newTestApp(t)
	return a, screen, root
}

func TestTheProjectTreeOpensAWindowNamedAfterTheProject(t *testing.T) {
	a, _, root := newTreeApp(t, "main.go")

	a.ProjectTree()

	if a.Desktop().Count() != 1 {
		t.Fatalf("Count() = %d, want the tree window", a.Desktop().Count())
	}
	if got := a.Desktop().Active().Title(); got != filepath.Base(root) {
		t.Errorf("the window is called %q, want %q", got, filepath.Base(root))
	}
	if a.activeView() != nil {
		t.Error("activeView() returned an editor for the tree window")
	}
}

func TestTheTreeIsRootedWhereTheEditorWasStarted(t *testing.T) {
	// The same rule .turbo-go follows, so "the project" means one thing.
	a, screen, _ := newTreeApp(t, "internal/", "main.go")

	a.ProjectTree()
	lines := render(t, a, screen)

	for _, want := range []string{"internal", "main.go"} {
		if !containsAnyLine(lines, want) {
			t.Errorf("the tree does not show %q", want)
		}
	}
}

func TestOpeningTheTreeTwiceRaisesTheSameWindow(t *testing.T) {
	a, _, _ := newTreeApp(t, "main.go")

	a.ProjectTree()
	first := a.Desktop().Active()
	a.NewFile()
	a.ProjectTree()

	if a.Desktop().Count() != 2 {
		t.Fatalf("Count() = %d, want the tree and the file", a.Desktop().Count())
	}
	if a.Desktop().Active() != first {
		t.Error("a second tree window was opened instead of raising the first")
	}
}

func TestF9OpensTheProjectTree(t *testing.T) {
	a, _, root := newTreeApp(t, "main.go")

	press(a, tcell.KeyF9, 0, tcell.ModNone)

	if a.Desktop().Count() != 1 {
		t.Fatalf("Count() = %d, want F9 to have opened the tree", a.Desktop().Count())
	}
	if got := a.Desktop().Active().Title(); got != filepath.Base(root) {
		t.Errorf("the window is called %q", got)
	}
}

func TestChoosingAFileInTheTreeOpensIt(t *testing.T) {
	a, _, root := newTreeApp(t, "main.go")
	writeTestFile(t, filepath.Join(root, "main.go"), "package main\n")
	a.ProjectTree()

	press(a, tcell.KeyEnter, 0, tcell.ModNone) // the highlight starts on main.go

	if a.Desktop().Count() != 2 {
		t.Fatalf("Count() = %d, want the tree and the opened file", a.Desktop().Count())
	}
	if got := a.Desktop().Active().Title(); got != "main.go" {
		t.Errorf("the front window is %q, want the file the tree opened", got)
	}
	if got := activeBuffer(t, a).Text(); got != "package main\n" {
		t.Errorf("the buffer holds %q", got)
	}
}

func TestChoosingADirectoryInTheTreeOpensNoWindow(t *testing.T) {
	a, _, _ := newTreeApp(t, "internal/", "main.go")
	a.ProjectTree()

	press(a, tcell.KeyEnter, 0, tcell.ModNone) // the highlight starts on internal/

	if a.Desktop().Count() != 1 {
		t.Errorf("Count() = %d; choosing a directory opened a window", a.Desktop().Count())
	}
}

func TestClosingTheTreeLetsANewOneOpen(t *testing.T) {
	a, _, _ := newTreeApp(t, "main.go")
	a.ProjectTree()

	a.CloseFile()

	if a.Desktop().Count() != 0 {
		t.Fatalf("Count() = %d, want the tree closed", a.Desktop().Count())
	}
	if a.Modals() != 0 {
		t.Error("closing the tree asked about unsaved changes")
	}

	a.ProjectTree()
	if a.Desktop().Count() != 1 {
		t.Error("the tree could not be opened again after being closed")
	}
}

func TestTheFileActionsLeaveTheTreeAlone(t *testing.T) {
	a, _, _ := newTreeApp(t, "main.go")
	a.ProjectTree()

	a.SaveFile()
	a.SaveFileAs()
	a.ToggleLineNumbers()
	a.RequestCompletion()

	if a.Modals() != 0 {
		t.Errorf("%d dialogs opened over the tree window", a.Modals())
	}
	if a.Desktop().Count() != 1 {
		t.Errorf("Count() = %d, want the tree still there", a.Desktop().Count())
	}
}

func TestSavingAFileRefreshesTheTree(t *testing.T) {
	a, screen, root := newTreeApp(t, "main.go")
	writeTestFile(t, filepath.Join(root, "main.go"), "package main\n")
	a.ProjectTree()
	a.Open(filepath.Join(root, "main.go"))

	// A file that appeared after the tree was read — as a build in a terminal
	// window would leave behind.
	if err := os.WriteFile(filepath.Join(root, "made-later.go"), nil, 0o644); err != nil {
		t.Fatalf("creating the file: %v", err)
	}
	if containsAnyLine(render(t, a, screen), "made-later.go") {
		t.Fatal("the tree showed the new file before anything refreshed it")
	}

	a.SaveFile()

	if !containsAnyLine(render(t, a, screen), "made-later.go") {
		t.Error("saving did not refresh the tree")
	}
}

func TestLeavingTheEditorWithATreeOpenAsksNothing(t *testing.T) {
	a, _, _ := newTreeApp(t, "main.go")
	a.ProjectTree()

	a.Quit()

	if !a.Quitting() {
		t.Error("Quit() did not leave with only a tree open")
	}
	if a.Modals() != 0 {
		t.Errorf("Quit() opened %d dialogs for a window with no unsaved work", a.Modals())
	}
}

// containsAnyLine reports whether any drawn row holds a piece of text.
func containsAnyLine(lines []string, want string) bool {
	for _, line := range lines {
		if strings.Contains(line, want) {
			return true
		}
	}
	return false
}