package cli

import (
	"net/http"
	"net/http/httptest"
	"testing"

	"github.com/gdamore/tcell/v2"
	api "sneak.berlin/go/neoirc/internal/cli/api"
	"sneak.berlin/go/neoirc/pkg/irc"
)

// The user's nick, a channel it is in, another user's nick and
// a message text, for the tests below.
const (
	testNick      = "erin"
	testChannel   = "#chan"
	testOtherNick = "bob"
	testText      = "hello"
)

func TestMemberPrefix(t *testing.T) {
	t.Parallel()

	tests := []struct {
		name   string
		member api.Member
		want   string
	}{
		{
			name:   "operator",
			member: api.Member{Nick: "alice", IsOperator: true},
			want:   "@",
		},
		{
			name:   "voiced member",
			member: api.Member{Nick: "bob", IsVoiced: true},
			want:   "+",
		},
		{
			name: "voiced operator",
			member: api.Member{
				Nick: "Carol", IsOperator: true, IsVoiced: true,
			},
			want: "@",
		},
		{
			name:   "plain member",
			member: api.Member{Nick: "dave"},
			want:   "",
		},
	}

	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			t.Parallel()

			got := memberPrefix(test.member)
			if got != test.want {
				t.Fatalf("got %q, want %q", got, test.want)
			}
		})
	}
}

// TestPartEvent checks that a PART event adds a line to the
// channel's buffer and marks it unread, except that the
// user's own part does not mark it unread.
func TestPartEvent(t *testing.T) {
	t.Parallel()

	tests := []struct {
		name       string
		from       string
		wantUnread int
	}{
		{name: "own part", from: testNick, wantUnread: 0},
		{name: "other member", from: testOtherNick, wantUnread: 1},
	}

	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			t.Parallel()

			app := &App{ui: NewUI(), nick: testNick}
			runUI(t, app.ui)

			app.handleServerMessage(&api.Message{
				Command: irc.CmdPart, From: test.from, To: testChannel,
			})

			lines, unread := bufferState(app.ui, testChannel)
			if lines != 1 || unread != test.wantUnread {
				t.Fatalf("got %d lines and %d unread, want 1 and %d",
					lines, unread, test.wantUnread)
			}
		})
	}
}

// TestOwnCommandShownOnce checks that a message, join or
// part made from neoirc-cli shows as one line in the
// channel's buffer once the server's event for it arrives,
// and does not mark the channel unread.
func TestOwnCommandShownOnce(t *testing.T) {
	t.Parallel()

	tests := []struct {
		name  string
		send  func(app *App)
		event api.Message
	}{
		{
			name: "message",
			send: func(app *App) { app.handleInput(testText) },
			event: api.Message{
				Command: irc.CmdPrivmsg, From: testNick, To: testChannel,
				Body: []string{testText},
			},
		},
		{
			name: "join",
			send: func(app *App) { app.cmdJoin(testChannel) },
			event: api.Message{
				Command: irc.CmdJoin, From: testNick, To: testChannel,
			},
		},
		{
			name: "part",
			send: func(app *App) { app.cmdPart(testChannel) },
			event: api.Message{
				Command: irc.CmdPart, From: testNick, To: testChannel,
			},
		},
	}

	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			t.Parallel()

			// The server accepts every command and answers nothing.
			server := httptest.NewServer(http.HandlerFunc(
				func(http.ResponseWriter, *http.Request) {},
			))
			t.Cleanup(server.Close)

			app := &App{
				ui:        NewUI(),
				client:    api.NewClient(server.URL),
				nick:      testNick,
				target:    testChannel,
				connected: true,
			}
			runUI(t, app.ui)
			app.ui.SwitchToBuffer(testChannel)

			test.send(app)
			app.handleServerMessage(&test.event)

			lines, unread := bufferState(app.ui, testChannel)
			if lines != 1 || unread != 0 {
				t.Fatalf("got %d lines and %d unread, want 1 and 0",
					lines, unread)
			}
		})
	}
}

// TestOwnEventFromOtherClient checks that a message, notice,
// join or part that the user's session makes from another
// client shows as one line in the buffer it belongs to.
func TestOwnEventFromOtherClient(t *testing.T) {
	t.Parallel()

	tests := []struct {
		name   string
		event  api.Message
		buffer string
	}{
		{
			name: "channel message",
			event: api.Message{
				Command: irc.CmdPrivmsg, From: testNick, To: testChannel,
				Body: []string{testText},
			},
			buffer: testChannel,
		},
		{
			name: "direct message",
			event: api.Message{
				Command: irc.CmdPrivmsg, From: testNick, To: testOtherNick,
				Body: []string{testText},
			},
			buffer: testOtherNick,
		},
		{
			name: "notice",
			event: api.Message{
				Command: irc.CmdNotice, From: testNick, To: testChannel,
				Body: []string{testText},
			},
			buffer: "(status)",
		},
		{
			name: "join",
			event: api.Message{
				Command: irc.CmdJoin, From: testNick, To: testChannel,
			},
			buffer: testChannel,
		},
		{
			name: "part",
			event: api.Message{
				Command: irc.CmdPart, From: testNick, To: testChannel,
			},
			buffer: testChannel,
		},
	}

	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			t.Parallel()

			app := &App{ui: NewUI(), nick: testNick}
			runUI(t, app.ui)

			app.handleServerMessage(&test.event)

			lines, _ := bufferState(app.ui, test.buffer)
			if lines != 1 {
				t.Fatalf("got %d lines in %s, want 1", lines, test.buffer)
			}
		})
	}
}

// bufferState returns the number of lines in the named
// buffer and how many of them are unread.
func bufferState(ui *UI, name string) (int, int) {
	var lines, unread int

	ui.app.QueueUpdate(func() {
		buf := ui.getOrCreateBuffer(name)
		lines = len(buf.Lines)
		unread = buf.Unread
	})

	return lines, unread
}

// runUI runs ui on a simulated screen until the test ends.
func runUI(t *testing.T, ui *UI) {
	t.Helper()

	ui.app.SetScreen(tcell.NewSimulationScreen(""))

	done := make(chan error)

	go func() { done <- ui.Run() }()

	t.Cleanup(func() {
		ui.Stop()

		err := <-done
		if err != nil {
			t.Errorf("run ui: %v", err)
		}
	})
}