package app

import (
	"path/filepath"
	"testing"
	"time"

	"rickub.com/turbo-editors/turbo-core/lsp"
)

// These tests cover what saving says to the language server. The defect they
// were written against: a window that started Untitled gains its path through
// Save As, afterSave sent only didSave, and a server ignores didSave for a
// document it was never told is open — so the window had no completion until
// the editor was restarted.

func TestSavingAnUntitledWindowAnnouncesItsDocument(t *testing.T) {
	project := t.TempDir()
	t.Chdir(project)
	a, _ := newTestApp(t)
	client, server := newFakeLanguage(t, a)
	connectLanguage(a, client)
	a.Tick() // the start-up announcement runs, and finds nothing to tell

	a.NewFile()
	typeText(a, "package main")
	path := filepath.Join(project, "main.go")
	a.save(a.ActiveView(), path)

	waitForMethod(t, server, "textDocument/didOpen")
	if got := server.methodCount("textDocument/didSave"); got != 0 {
		t.Errorf("didSave was sent %d times for a document the server was never told is open", got)
	}
	if !a.language.Knows(path) {
		t.Errorf("after the save, the server still does not know %q", path)
	}
}

func TestSaveAsUnderANewNameClosesTheOldDocument(t *testing.T) {
	project := t.TempDir()
	t.Chdir(project)
	a, _ := newTestApp(t)
	client, server := newFakeLanguage(t, a)
	connectLanguage(a, client)

	writeTestFile(t, filepath.Join(project, "old.go"), "package main\n")
	a.Open("old.go")
	waitForMethod(t, server, "textDocument/didOpen")

	newPath := filepath.Join(project, "new.go")
	a.save(a.ActiveView(), newPath)

	waitForMethod(t, server, "textDocument/didClose")
	if a.language.Knows("old.go") {
		t.Errorf("the old document is still open on the server after Save As gave the buffer a new name")
	}
	if !a.language.Knows(newPath) {
		t.Errorf("the new document was never announced to the server")
	}
}

func TestSaveAsToTheSamePathClosesNothing(t *testing.T) {
	// Save As offered the file's own name and the user accepted it: that is a
	// write, not a rename, however the dialog spelt the path.
	project := t.TempDir()
	t.Chdir(project)
	a, _ := newTestApp(t)
	client, server := newFakeLanguage(t, a)
	connectLanguage(a, client)

	writeTestFile(t, filepath.Join(project, "main.go"), "package main\n")
	a.Open("main.go") // relative, as the command line gives it
	waitForMethod(t, server, "textDocument/didOpen")

	a.save(a.ActiveView(), filepath.Join(project, "main.go")) // absolute, as the dialog gives it

	waitForMethod(t, server, "textDocument/didSave")
	if got := server.methodCount("textDocument/didClose"); got != 0 {
		t.Errorf("didClose was sent %d times for a save that renamed nothing", got)
	}
}

func TestSavingAKnownDocumentReportsTheWrite(t *testing.T) {
	project := t.TempDir()
	t.Chdir(project)
	a, _ := newTestApp(t)
	client, server := newFakeLanguage(t, a)
	connectLanguage(a, client)

	writeTestFile(t, filepath.Join(project, "main.go"), "package main\n")
	a.Open("main.go")
	waitForMethod(t, server, "textDocument/didOpen")

	a.save(a.ActiveView(), a.ActiveView().Buffer().Path())

	waitForMethod(t, server, "textDocument/didSave")
	if got := server.methodCount("textDocument/didOpen"); got != 1 {
		t.Errorf("didOpen was sent %d times; saving an open document must not re-announce it", got)
	}
}

func TestSavingANewFileTellsTheServerTheFileExists(t *testing.T) {
	// To moon-lsp a document being open and a file existing are two facts,
	// and it works a package's files out from the directory: a .mbt saved for
	// the first time got no diagnostics, however loudly the document had been
	// announced, until the server was told the file is there. Found on macOS
	// the first time Turbo MoonBit's suite ran there; confirmed at the
	// protocol level — the same file is diagnosed the moment
	// workspace/didChangeWatchedFiles names it.
	project := t.TempDir()
	t.Chdir(project)
	a, _ := newTestApp(t)
	client, server := newFakeLanguage(t, a)
	connectLanguage(a, client)
	a.Tick()

	a.NewFile()
	typeText(a, "package main")
	path := filepath.Join(project, "main.go")
	a.save(a.ActiveView(), path)

	waitForMethod(t, server, "workspace/didChangeWatchedFiles")
	events := server.lastFileEvents()
	if len(events) != 1 || events[0].Type != lsp.FileCreated {
		t.Fatalf("the server was told %+v, want one created file", events)
	}
	if want := lsp.PathToURI(path); events[0].URI != want {
		t.Errorf("the created file is %q, want %q", events[0].URI, want)
	}
	// The document first, then the file: the order the fix was verified in.
	methods := server.methodsSeen()
	if open, created := firstIndexOf(methods, "textDocument/didOpen"), firstIndexOf(methods, "workspace/didChangeWatchedFiles"); open < 0 || created < open {
		t.Errorf("the file was reported before the document was announced: %v", methods)
	}
}

func TestSavingAnExistingFileDoesNotClaimItWasCreated(t *testing.T) {
	// A file that was already on disk is not news to the server, and a save
	// that claimed otherwise would have moon-lsp rescan the package on every
	// Ctrl-S.
	project := t.TempDir()
	t.Chdir(project)
	t.Setenv(testProfile().SnippetDirEnvVar(), t.TempDir())
	a, _ := newTestApp(t)
	client, server := newFakeLanguage(t, a)
	connectLanguage(a, client)
	path := filepath.Join(project, "main.go")
	writeTestFile(t, path, "package main\n")
	a.Open(path)
	a.Tick()

	a.save(a.ActiveView(), path)

	waitForMethod(t, server, "textDocument/didSave")
	if got := server.methodCount("workspace/didChangeWatchedFiles"); got != 0 {
		t.Errorf("saving a file that already existed reported it created %d time(s)", got)
	}
}

func TestAutosaveOfANewlyNamedFileTellsTheServerTheFileExists(t *testing.T) {
	// The other way a file gets written. `turbo-moonbit new.mbt` opens a
	// buffer for a file that is not on disk yet; the first automatic save
	// creates it, and the server has to hear that from this path too.
	project := t.TempDir()
	t.Chdir(project)
	t.Setenv(testProfile().SnippetDirEnvVar(), t.TempDir())
	a, _ := newTestApp(t)
	client, server := newFakeLanguage(t, a)
	connectLanguage(a, client)
	path := filepath.Join(project, "new.go")
	a.Open(path) // not on disk: an empty buffer with that name
	a.Tick()
	a.SetAutosave(true, time.Millisecond)

	typeText(a, "package main")
	deadline := time.Now().Add(2 * time.Second)
	for server.methodCount("workspace/didChangeWatchedFiles") == 0 && time.Now().Before(deadline) {
		time.Sleep(2 * time.Millisecond)
		a.Tick()
	}

	events := server.lastFileEvents()
	if len(events) != 1 || events[0].Type != lsp.FileCreated || events[0].URI != lsp.PathToURI(path) {
		t.Errorf("autosave reported %+v, want %s created", events, path)
	}
}

// firstIndexOf returns where a string first appears in a list, or -1.
func firstIndexOf(list []string, want string) int {
	for i, s := range list {
		if s == want {
			return i
		}
	}
	return -1
}