// gomuks - A terminal Matrix client written in Go.
// Copyright (C) 2018 Tulir Asokan
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package main

import (
	"fmt"
	"strings"

	"github.com/gdamore/tcell"
	"maunium.net/go/gomatrix"
	"maunium.net/go/tview"
)

type RoomView struct {
	*tview.Box

	topic    *tview.TextView
	content  *tview.TextView
	status   *tview.TextView
	userlist *tview.TextView
	name     string
}

func NewRoomView(name, topic string) *RoomView {
	view := &RoomView{
		Box: tview.NewBox(),
		topic:    tview.NewTextView(),
		content:  tview.NewTextView(),
		status:   tview.NewTextView(),
		userlist: tview.NewTextView(),
		name:     name,
	}
	view.topic.SetText(topic).SetBackgroundColor(tcell.ColorDarkGreen)
	view.status.SetBackgroundColor(tcell.ColorDimGray)
	view.userlist.SetText("@tulir:maunium.net\n@tulir_test:maunium.net")
	return view
}

func (view *RoomView) Draw(screen tcell.Screen) {
	x, y, width, height := view.GetRect()
	view.topic.SetRect(x, y, width, 1)
	view.content.SetRect(x, y+1, width-30, height-2)
	view.status.SetRect(x, y+height-1, width,1)
	view.userlist.SetRect(x+width-29, y+1, 29, height - 2)

	view.topic.Draw(screen)
	view.content.Draw(screen)
	view.status.Draw(screen)

	borderX := x+width-30
	background := tcell.StyleDefault.Background(view.GetBackgroundColor()).Foreground(view.GetBorderColor())
	for borderY := y + 1; borderY < y + height - 1; borderY++ {
		screen.SetContent(borderX, borderY, tview.GraphicsVertBar, nil, background)
	}
	view.userlist.Draw(screen)
}

type Border struct {
	*tview.Box
}

func NewBorder() *Border {
	return &Border{tview.NewBox()}
}

func (border *Border) Draw(screen tcell.Screen) {
	background := tcell.StyleDefault.Background(border.GetBackgroundColor()).Foreground(border.GetBorderColor())
	x, y, width, height := border.GetRect()
	if width == 1 {
		for borderY := y; borderY < y + height; borderY++ {
			screen.SetContent(x, borderY, tview.GraphicsVertBar, nil, background)
		}
	} else if height == 1 {
		for borderX := x; borderX < x + width; borderX++ {
			screen.SetContent(borderX, y, tview.GraphicsHoriBar, nil, background)
		}
	}
}

func (ui *GomuksUI) MakeMainUI() tview.Primitive {
	ui.mainView = tview.NewGrid()
	ui.mainView.SetColumns(30, 1, 0).SetRows(0, 1)

	ui.mainViewRoomList = tview.NewList().ShowSecondaryText(false)
	ui.mainViewRoomList.SetBorderPadding(0, 0, 0, 1)
	ui.mainView.AddItem(ui.mainViewRoomList, 0, 0, 2, 1, 0, 0, false)

	ui.mainView.AddItem(NewBorder(), 0, 1, 2, 1, 0, 0, false)

	ui.mainViewRoomView = tview.NewPages()
	ui.mainViewRoomView.SetChangedFunc(ui.Render)
	ui.mainView.AddItem(ui.mainViewRoomView, 0, 2, 1, 1, 0, 0, false)

	ui.mainViewInput = tview.NewInputField()
	ui.mainViewInput.SetChangedFunc(func(_ string) {
		ui.matrix.SendTyping(ui.currentRoom())
	})
	ui.mainViewInput.SetDoneFunc(func(key tcell.Key) {
		if key == tcell.KeyEnter {
			room, text := ui.currentRoom(), ui.mainViewInput.GetText()
			if len(text) == 0 {
				return
			} else if text[0] == '/' {
				args := strings.SplitN(text, " ", 2)
				command := strings.ToLower(args[0])
				args = args[1:]
				ui.HandleCommand(room, command, args)
			} else {
				ui.matrix.SendMessage(room, text)
			}
			ui.mainViewInput.SetText("")
		}
	})
	ui.mainView.AddItem(ui.mainViewInput, 1, 2, 1, 1, 0, 0, true)

	ui.debug.Print(ui.mainViewInput.SetInputCapture(ui.MainUIKeyHandler))

	ui.mainViewRooms = make(map[string]*RoomView)

	return ui.mainView
}

func (ui *GomuksUI) HandleCommand(room, command string, args []string) {
	ui.debug.Print("Handling command", command, args)
	switch command {
	case "/quit":
		ui.gmx.Stop()
	case "/clearcache":
		ui.config.Session.Rooms = make(map[string]*gomatrix.Room)
		ui.config.Session.NextBatch = ""
		ui.config.Session.FilterID = ""
		ui.config.Session.Save()
		ui.gmx.Stop()
	case "/part":
	case "/leave":
		ui.matrix.client.LeaveRoom(room)
	case "/join":
		if len(args) == 0 {
			ui.Append(room, "*", "Usage: /join <room>")
		}
		mxid := args[0]
		server := mxid[strings.Index(mxid, ":")+1:]
		ui.matrix.client.JoinRoom(mxid, server, nil)
	}
}

func (ui *GomuksUI) MainUIKeyHandler(key *tcell.EventKey) *tcell.EventKey {
	if key.Modifiers() == tcell.ModCtrl {
		if key.Key() == tcell.KeyDown {
			ui.SwitchRoom(ui.currentRoomIndex + 1)
			ui.mainViewRoomList.SetCurrentItem(ui.currentRoomIndex)
		} else if key.Key() == tcell.KeyUp {
			ui.SwitchRoom(ui.currentRoomIndex - 1)
			ui.mainViewRoomList.SetCurrentItem(ui.currentRoomIndex)
		} else {
			return key
		}
	} else if key.Key() == tcell.KeyPgUp || key.Key() == tcell.KeyPgDn {
		ui.mainViewRooms[ui.currentRoom()].InputHandler()(key, nil)
	} else {
		return key
	}
	return nil
}

func (ui *GomuksUI) SetRoomList(rooms []string) {
	ui.roomList = rooms
	ui.mainViewRoomList.Clear()
	for index, room := range rooms {
		localRoomIndex := index

		ui.matrix.UpdateRoomInfo(room)
		roomStore := ui.matrix.config.Session.LoadRoom(room)

		name := room
		topic := ""
		if roomStore != nil {
			nameEvt := roomStore.GetStateEvent("m.room.title", "")
			if nameEvt != nil {
				name, _ = nameEvt.Content["title"].(string)
			} else {
				nameEvt = roomStore.GetStateEvent("m.room.canonical_alias", "")
				if nameEvt != nil {
					name, _ = nameEvt.Content["alias"].(string)
				}
			}
			topicEvt := roomStore.GetStateEvent("m.room.topic", "")
			if topicEvt != nil {
				topic, _ = topicEvt.Content["topic"].(string)
				topic = strings.Replace(topic, "\n", " ", -1)
			}
		}
		ui.mainViewRoomList.AddItem(name, "", 0, func() {
			ui.SwitchRoom(localRoomIndex)
		})
		if !ui.mainViewRoomView.HasPage(room) {
			roomView := NewRoomView(name, topic)
			ui.mainViewRooms[room] = roomView
			ui.mainViewRoomView.AddPage(room, roomView, true, false)
		}
	}
	ui.SwitchRoom(0)
}

func (ui *GomuksUI) currentRoom() string {
	if len(ui.roomList) == 0 {
		return ""
	}
	return ui.roomList[ui.currentRoomIndex]
}

func (ui *GomuksUI) SwitchRoom(roomIndex int) {
	if roomIndex < 0 {
		roomIndex = len(ui.roomList) - 1
	}
	ui.currentRoomIndex = roomIndex % len(ui.roomList)
	ui.mainViewRoomView.SwitchToPage(ui.currentRoom())
}

func (ui *GomuksUI) SetTyping(room string, users ...string) {
	roomView, ok := ui.mainViewRooms[room]
	if ok {
		if len(users) > 0 {
			roomView.status.SetText("Typing: " + strings.Join(users, ", "))
		} else {
			roomView.status.SetText("")
		}
		ui.Render()
	}
}

func (ui *GomuksUI) Append(room, sender, message string) {
	roomView, ok := ui.mainViewRooms[room]
	if ok {
		fmt.Fprintf(roomView.content, "<%s> %s\n", sender, message)
		ui.Render()
	}
}