package main

import (
	"errors"
	"fmt"
	"strings"
	"time"

	todotxt "github.com/br0xen/go-todotxt"
	"github.com/br0xen/termbox-screen"
	"github.com/br0xen/termbox-util"
	termbox "github.com/nsf/termbox-go"
)

const (
	FieldTaskTodo = iota
	FieldTaskPriority
	FieldTaskProjects
	FieldTaskContexts
	FieldTaskTags
	FieldTaskError

	TaskBundleTaskIdKey = "taskscreen.taskid"
)

type TaskScreen struct {
	message *Message
	cursor  int

	currentTaskId int
	displayTask   *todotxt.Task
	fieldLabels   map[int]string
	editing       bool

	inputField *termboxUtil.InputField
}

func (screen *TaskScreen) GetFieldValue(fld int) string {
	switch fld {
	case FieldTaskTodo:
		return screen.displayTask.Todo
	case FieldTaskPriority:
		return screen.displayTask.Priority
	case FieldTaskProjects:
		return strings.Join(screen.displayTask.Projects, ",")
	case FieldTaskContexts:
		return strings.Join(screen.displayTask.Contexts, ",")
	case FieldTaskTags:
		var ret []string
		for k, v := range screen.displayTask.AdditionalTags {
			ret = append(ret, k+":"+v)
		}
		return strings.Join(ret, ",")
	}
	return ""
}

func (screen *TaskScreen) Id() int { return ScreenIdTask }

func (screen *TaskScreen) Initialize(bundle termboxScreen.Bundle) error {
	screen.fieldLabels = make(map[int]string)
	screen.fieldLabels[FieldTaskTodo] = "Todo"
	screen.fieldLabels[FieldTaskPriority] = "Priority"
	screen.fieldLabels[FieldTaskProjects] = "Projects"
	screen.fieldLabels[FieldTaskContexts] = "Contexts"
	screen.fieldLabels[FieldTaskTags] = "Tags"
	var err error
	width, height := termbox.Size()
	screen.inputField = termboxUtil.CreateInputField(2, (height - 3), width, 1, DefaultFg, DefaultBg)
	screen.message = NewMessage("", DefaultFg, DefaultBg, time.Second*2)
	if bundle != nil {
		screen.currentTaskId = bundle.GetInt(TaskBundleTaskIdKey, -1)
	}
	if screen.currentTaskId == -1 {
		return errors.New("Task Screen Initialization Failed")
	}
	if screen.displayTask, err = app.TaskList.GetTask(screen.currentTaskId); err != nil {
		return err
	}
	screen.cursor = FieldTaskTodo
	return nil
}

func (screen *TaskScreen) ResizeScreen() { screen.Initialize(nil) }

func (screen *TaskScreen) HandleKeyEvent(event termbox.Event) int {
	if screen.editing {
		return screen.handleEditingKeyEvent(event)
	}
	if event.Key == termbox.KeyEnter {
		screen.editing = true
		screen.inputField.SetTitle(screen.fieldLabels[screen.cursor] + ": ")
		screen.inputField.SetValue(screen.GetFieldValue(screen.cursor))
		screen.inputField.SetActive(true)
		return screen.Id()

	} else if event.Key == termbox.KeyBackspace || event.Key == termbox.KeyBackspace2 || event.Ch == 'h' || event.Key == termbox.KeyArrowLeft {
		bundle := termboxScreen.Bundle{}
		bundle.SetValue(MainBundleListKey, MainBundleListCurrent)
		app.uiManager.InitializeScreen(ScreenIdMain, bundle)
		return ScreenIdMain

	} else if event.Ch == 'j' || event.Key == termbox.KeyArrowDown {
		screen.moveCursorDown()

	} else if event.Ch == 'k' || event.Key == termbox.KeyArrowUp {
		screen.moveCursorUp()
	}
	return screen.Id()
}
func (screen *TaskScreen) HandleNoneEvent(event termbox.Event) int { return screen.Id() }

func (screen *TaskScreen) DrawScreen() {
	screen.drawHeader()

	yPos := 1
	if screen.cursor == FieldTaskTodo {
		termboxUtil.DrawStringAtPoint(screen.displayTask.Todo, 0, yPos, CursorBg, CursorFg)
	} else {
		termboxUtil.DrawStringAtPoint(screen.displayTask.Todo, 0, yPos, DefaultFg, DefaultBg)
	}
	yPos++
	if screen.cursor == FieldTaskPriority {
		termboxUtil.DrawStringAtPoint(fmt.Sprintf("Priority: %s", screen.displayTask.Priority), 0, yPos, CursorBg, CursorFg)
	} else {
		termboxUtil.DrawStringAtPoint(fmt.Sprintf("Priority: %s", screen.displayTask.Priority), 0, yPos, DefaultFg, DefaultBg)
	}
	yPos++
	if screen.cursor == FieldTaskProjects {
		termboxUtil.DrawStringAtPoint(fmt.Sprintf("Projects: %s", screen.displayTask.Projects), 0, yPos, CursorBg, CursorFg)
	} else {
		termboxUtil.DrawStringAtPoint(fmt.Sprintf("Projects: %s", screen.displayTask.Projects), 0, yPos, DefaultFg, DefaultBg)
	}
	yPos++
	if screen.cursor == FieldTaskContexts {
		termboxUtil.DrawStringAtPoint(fmt.Sprintf("Contexts: %s", screen.displayTask.Contexts), 0, yPos, CursorBg, CursorFg)
	} else {
		termboxUtil.DrawStringAtPoint(fmt.Sprintf("Contexts: %s", screen.displayTask.Contexts), 0, yPos, DefaultFg, DefaultBg)
	}
	yPos++
	if screen.cursor == FieldTaskTags {
		termboxUtil.DrawStringAtPoint("Additional Tags: ", 0, yPos, CursorBg, CursorFg)
	} else {
		termboxUtil.DrawStringAtPoint("Additional Tags: ", 0, yPos, DefaultFg, DefaultBg)
	}
	yPos++
	for k, v := range screen.displayTask.AdditionalTags {
		termboxUtil.DrawStringAtPoint(fmt.Sprintf("%s: %s", k, v), 0, yPos, DefaultFg, DefaultBg)
		yPos++
	}

	if screen.editing {
		w, h := termbox.Size()
		termboxUtil.DrawBorder(0, h-4, w-1, h-2, CursorBg, CursorFg)
		termboxUtil.FillWithChar(' ', 1, h-3, w-2, h-3, DefaultFg, DefaultBg)
		screen.inputField.Draw()
	}

	screen.drawFooter()
}

func (screen *TaskScreen) handleEditingKeyEvent(event termbox.Event) int {
	if event.Key == termbox.KeyEnter {
		var needsSave bool
		// Save the change
		switch screen.cursor {
		case FieldTaskTodo:
			//screen.displayTask.Todo = screen.inputField.GetValue()
			if screen.inputField.GetValue() != screen.displayTask.Todo {
				screen.displayTask.Todo = screen.inputField.GetValue()
				needsSave = true
			}
		case FieldTaskPriority:
			val := screen.inputField.GetValue()
			if len(val) > 0 {
				val = string(val[0])
			}
			if val != screen.displayTask.Priority {
				screen.displayTask.Priority = val
				needsSave = true
			}
		case FieldTaskProjects:
			projects := splitFields(screen.inputField.GetValue())
			if !isCombination(projects, screen.displayTask.Projects) {
				needsSave = true
				screen.displayTask.Projects = []string{}
				for _, v := range projects {
					screen.displayTask.Projects = append(screen.displayTask.Projects, v)
				}
			}
		case FieldTaskContexts:
			contexts := splitFields(screen.inputField.GetValue())
			if !isCombination(contexts, screen.displayTask.Contexts) {
				needsSave = true
				screen.displayTask.Contexts = []string{}
				for _, v := range contexts {
					screen.displayTask.Contexts = append(screen.displayTask.Contexts, v)
				}
			}
		case FieldTaskTags:
			tagsSlice := splitFields(screen.inputField.GetValue())
			if !sliceIsValidTags(tagsSlice) {
				screen.message.Set("Tags should be in format <key>:<val>")
				return screen.Id()
			}
			if !isCombination(tagsSlice, tagsToSlice(screen.displayTask.AdditionalTags)) {
				needsSave = true
				screen.displayTask.AdditionalTags = make(map[string]string)
				for k, v := range sliceToTags(tagsSlice) {
					screen.displayTask.AdditionalTags[k] = v
				}
			}
		}
		if needsSave {
			if err := app.saveTask(screen.displayTask); err != nil {
				screen.message.SetError(err.Error())
			}
		}
		screen.editing = false
		screen.inputField.SetActive(false)
	} else {
		if screen.inputField.HandleEvent(event) {

		}
	}
	return screen.Id()
}

func (screen *TaskScreen) drawHeader() {
	width, _ := termbox.Size()
	headerString := screen.displayTask.Todo
	spaces := strings.Repeat(" ", ((width-len(headerString))/2)+1)
	termboxUtil.DrawStringAtPoint(fmt.Sprintf("%s%s%s", spaces, headerString, spaces), 0, 0, TitleFg, TitleBg)
}

func (screen *TaskScreen) drawFooter() {
	_, height := termbox.Size()
	screen.message.DrawAt(0, height-1)
}

func (screen *TaskScreen) moveCursorDown() bool {
	screen.cursor = (screen.cursor + 1) % FieldTaskError
	return true
}

func (screen *TaskScreen) moveCursorUp() bool {
	if screen.cursor > 0 {
		screen.cursor--
	} else {
		screen.cursor = FieldTaskError - 1
	}
	return true
}

func (screen *TaskScreen) editCurrentField() {

}