package ui

import (
	"fmt"
	"os"
	"time"

	"git.bullercodeworks.com/brian/gime/cli"
	"git.bullercodeworks.com/brian/wandle"
	"github.com/nsf/termbox-go"
)

// Screen/Source Ids
const (
	ListTimersId = ScreenMsgSource(iota << 8)
	SettingsId
	ErrorId
)

// Commands
const (
	CmdCanceled = ScreenMsgCommand(iota)
	CmdSaved

	// Goto Screen Commands
	CmdGotoSettings
	CmdGotoTimerList
)

func RunTUI(p *cli.Program) error {
	ui := NewUi(p)
	ui.debug = true
	if err := ui.Start(); err != nil {
		return err
	}
	// Exiting
	fmt.Printf("Done\n")
	return nil
}

type Ui struct {
	debug   bool
	wandle  *wandle.Program
	program *cli.Program
	err     error

	screens map[ScreenMsgSource]wandle.Screen

	prevScreen, currScreen ScreenMsgSource
}

func NewUi(p *cli.Program) *Ui {
	ui := &Ui{
		screens: make(map[ScreenMsgSource]wandle.Screen),
		program: p,
		err:     p.Initialize(),
	}
	var s wandle.Screen
	var sId ScreenMsgSource
	if ui.err != nil {
		s, sId = NewSettingsScreen(ui), SettingsId
	} else {
		if ui.err = ui.program.LoadTimerList(); ui.err != nil {
			s, sId = NewSettingsScreen(ui), SettingsId
		} else if ui.err = ui.program.LoadDoneList(); ui.err != nil {
			s, sId = NewSettingsScreen(ui), SettingsId
		} else {
			s, sId = NewListTimersScreen(ui), ListTimersId
		}
	}
	ui.screens[sId] = s
	ui.currScreen = sId
	ui.wandle = wandle.NewProgram(s)
	ui.wandle.Style(wandle.NewStyle(
		termbox.RGBToAttribute(uint8(0), uint8(255), uint8(0)),
		termbox.RGBToAttribute(uint8(0), uint8(0), uint8(0)),
	))
	return ui
}

func (u *Ui) GotoScreen(id ScreenMsgSource) func() wandle.Msg {
	u.prevScreen, u.currScreen = u.currScreen, id
	if s, ok := u.screens[id]; ok {
		return wandle.SwitchScreenCmd(s)
	}
	var s wandle.Screen
	switch id {
	case ListTimersId:
		s = NewListTimersScreen(u)
	case SettingsId:
		s = NewSettingsScreen(u)
	}
	u.screens[id] = s
	return wandle.SwitchScreenCmd(s)
}
func (u *Ui) CanGoBack() bool {
	return u.prevScreen > 0
}
func (u *Ui) GoBack() func() wandle.Msg {
	if !u.CanGoBack() {
		return nil
	}
	return u.GotoScreen(u.prevScreen)
}

func (u *Ui) Log(v string) error {
	f, err := os.OpenFile("gime.log", os.O_APPEND|os.O_WRONLY|os.O_CREATE, 0600)
	if err != nil {
		panic(err)
	}
	defer f.Close()
	_, err = f.WriteString(fmt.Sprintf("%s: %s\n", time.Now().Format(time.RFC3339), v))
	return err
}

func (u *Ui) Start() error {
	return u.wandle.Start()
}

type ScreenMsg struct {
	source  ScreenMsgSource
	command ScreenMsgCommand
	data    interface{}
	err     error
}

type ScreenMsgSource int
type ScreenMsgCommand int