package ui

import (
	"fmt"
	"path/filepath"
	"strings"
	"time"

	"git.bullercodeworks.com/brian/boltbrowser/models"
	"git.bullercodeworks.com/brian/wandle"
	"git.bullercodeworks.com/brian/widdles"
	"github.com/nsf/termbox-go"
	"github.com/spf13/viper"
	bolt "go.etcd.io/bbolt"
)

const (
	BS_CmdRefresh = BrowseId | iota
	BS_CmdDBTimeout
)

type BrowseMsg struct {
	source int
	data   interface{}
	err    error
}

type browseScreen struct {
	ui     *Ui
	dbPath string
	db     *models.BoltDB

	status *widdles.Text

	treePane  *BoltTreePane
	rightPane ViewPort
}

func NewBrowseScreen(u *Ui) *browseScreen { return &browseScreen{ui: u} }

func (s *browseScreen) Init() wandle.Cmd {
	w, h := termbox.Size()
	dbs := viper.GetStringSlice("dbs")
	dbidx := viper.GetInt("dbidx")
	if len(dbs) <= dbidx {
		return wandle.Quit
	}
	s.dbPath = dbs[dbidx]
	s.treePane = NewBoltTreePane(0, 3, w/2, h-2)

	s.status = widdles.NewText("Press '?' for help", 0, (h - 1), w, 1)

	return func() wandle.Msg {
		timeout, err := time.ParseDuration(viper.GetString("version"))
		if err != nil {
			timeout = time.Second
		}
		db, err := bolt.Open(s.dbPath, 0600, &bolt.Options{Timeout: timeout})
		if err == bolt.ErrTimeout {
			return func() wandle.Msg { return BrowseMsg{source: BS_CmdDBTimeout} }
		}
		s.db = models.NewBoltDB(db)
		if viper.GetBool("readonly") {
			db.Close()
		}
		s.treePane.SetDB(s.db)
		s.resizeWindow(w, h)
		return nil
	}
}

func (s *browseScreen) Update(msg wandle.Msg) wandle.Cmd {
	switch msg := msg.(type) {
	case BrowseMsg:
		return s.handleBrowseMsg(msg)
	case termbox.Event:
		return s.handleTermboxEvent(msg)
	}
	return nil
}

func (s *browseScreen) handleBrowseMsg(msg BrowseMsg) wandle.Cmd {
	switch msg.source {
	}
	return nil
}

func (s *browseScreen) handleTermboxEvent(msg termbox.Event) wandle.Cmd {
	switch msg.Type {
	case termbox.EventKey:
		if cmd := s.treePane.Update(msg); cmd != nil {
			return cmd
		}
		if msg.Ch == '?' {
			return wandle.SwitchScreenCmd(NewAboutScreen(s.ui))
		} else if msg.Ch == 'q' || msg.Key == termbox.KeyCtrlC {
			return wandle.Quit
		} else if msg.Key == termbox.KeyCtrlN {
			// Next File
			idx := viper.GetInt("dbidx") + 1
			if idx >= len(viper.GetStringSlice("dbs")) {
				s.setStatus("Already at last file", time.Second)
			} else {
				viper.Set("dbidx", idx)
				return wandle.SwitchScreenCmd(NewBrowseScreen(s.ui))
			}
		} else if msg.Key == termbox.KeyCtrlP {
			// Previous File
			idx := viper.GetInt("dbidx") - 1
			if idx < 0 {
				s.setStatus("Already at first file", time.Second)
			} else {
				viper.Set("dbidx", idx)
				return wandle.SwitchScreenCmd(NewBrowseScreen(s.ui))
			}
		}
	case termbox.EventResize:
		s.resizeWindow(msg.Width, msg.Height)
	}
	return nil
}

func (s *browseScreen) resizeWindow(w, h int) {
	lw := w
	if lw > 80 {
		lw = lw / 2
	}
	// Re-build Tree pane
	s.treePane.SetWidth(lw)
	// Re-build Right Pane buffer
	s.rightPane = ViewPort{
		x:      lw + 1,
		width:  w - lw,
		height: h - 2,
	}
}

func (s *browseScreen) View(style wandle.Style) {
	w, h := termbox.Size()
	s.drawHeader(style)
	s.treePane.View(style)
	if w > 80 {
		x := s.rightPane.GetX() - 1
		termbox.SetCell(x, 1, '╦', style.Foreground, style.Background)
		wandle.Fill('║', x, 2, x, h-1, style)
		s.rightPane.View(style)
	}
	s.status.View(style)
}

func (s *browseScreen) drawHeader(style wandle.Style) {
	width, _ := termbox.Size()
	headerStringLen := func(fileName string) int {
		return len("boltbrowser") + len(fileName) + 1
	}
	headerFileName := s.dbPath
	if headerStringLen(headerFileName) > width {
		headerFileName = filepath.Base(headerFileName)
	}
	headerString := "boltbrowser" + ": " + headerFileName
	count := ((width - len(headerString)) / 2) + 1
	if count < 0 {
		count = 0
	}
	spaces := strings.Repeat(" ", count)
	wandle.Print(0, 0, style, fmt.Sprintf("%s%s%s", spaces, headerString, spaces))
	wandle.Fill('═', 0, 1, width, 1, style)
}

func (s *browseScreen) setStatus(status string, timeout time.Duration) {
	s.status.SetText(status)
	if timeout > 0 {
		go func() {
			time.Sleep(timeout)
			if s.status.GetText() == status {
				s.status.SetText("Press '?' for help")
				s.ui.wandle.Send(BS_CmdRefresh)
			}
		}()
	}
}