package main

import (
	"fmt"
	"os"
	"strings"

	todotxt "github.com/br0xen/go-todotxt"
	"github.com/br0xen/user-config"
)

type AppState struct {
	Name            string
	Version         int
	config          *userConfig.Config
	directory       string
	fileTodo        string
	fileDone        string
	fileReport      string
	ValidOperations map[string][]string
	OpFuncs         map[string]func([]string) int

	TaskList *todotxt.TaskList
	DoneList *todotxt.TaskList

	screens []Screen
}

func NewApp() *AppState {
	app := &AppState{Name: AppName, Version: AppVersion}
	app.initialize()
	app.doVersionCheck()
	if err := app.LoadTaskList(); err != nil {
		if len(os.Args) > 1 && os.Args[1] != "--reinit" {
			panic(err)
		}
	}
	return app
}

func (a *AppState) run(parms []string) int {
	if len(parms) == 0 || parms[0] == "ui" {
		// UI Mode
		return uiLoop()
	}
	if fn, ok := a.OpFuncs[parms[0]]; ok {
		return fn(parms[1:])
	}
	fmt.Println("Unknown Command")
	return 1
}

func (a *AppState) filterList(list *todotxt.TaskList, filter string) *todotxt.TaskList {
	return list.Filter(a.getFilterPredicate(filter))
}

func (a *AppState) getFilteredList(filter string) *todotxt.TaskList {
	return a.TaskList.Filter(a.getFilterPredicate(filter))
}

func (a *AppState) getFilteredDoneList(filter string) *todotxt.TaskList {
	return a.DoneList.Filter(a.getFilterPredicate(filter))
}

func (a *AppState) getTodoFile() string {
	return a.directory + a.fileTodo
}
func (a *AppState) getDoneFile() string {
	return a.directory + a.fileDone
}
func (a *AppState) getReportFile() string {
	return a.directory + a.fileReport
}

func (a *AppState) addOperation(name string, desc []string, fn func([]string) int) {
	a.ValidOperations[name] = desc
	a.OpFuncs[name] = fn
}

func (a *AppState) getTaskString(task todotxt.Task) string {
	var completed string
	completed = " "
	if task.Completed {
		completed = "X"
	}
	return fmt.Sprintf("%d. [%s] %s", task.Id, completed, strings.TrimPrefix(task.String(), "x "))
}

func (a *AppState) getDoneTaskString(task todotxt.Task) string {
	var completed string
	completed = " "
	if task.Completed {
		completed = "X"
	}
	return fmt.Sprintf("0. [%s] %s", completed, strings.TrimPrefix(task.String(), "x "))
}

func (a *AppState) doVersionCheck() {
	confVer, _ := a.config.GetInt("version")
	for confVer < a.Version {
		confVer = a.migrate(confVer, a.Version)
	}
	a.config.SetInt("version", confVer)
}

func (a *AppState) migrate(from, to int) int {
	if from == to {
		return to
	}
	switch from {
	case 0:
		a.initializeConfig()
		return 1
	}
	// If we get all the way down here, we _must_ be done.
	return to
}

func (a *AppState) initialize() {
	var err error
	a.config, err = userConfig.NewConfig(a.Name)
	if err != nil {
		panic(err)
	}
	a.ValidOperations = make(map[string][]string)
	a.OpFuncs = make(map[string]func([]string) int)
	a.addOperation("ls",
		[]string{"ls                         - List Tasks"},
		a.opListTasks,
	)
	a.addOperation("lsa",
		[]string{"lsa                        - The same as 'ls -a'"},
		func(args []string) int {
			return a.opListTasks(append([]string{"-a"}, args...))
		},
	)
	a.addOperation("add",
		[]string{"add                        - Add a task"},
		a.opAddTask,
	)
	a.addOperation("new",
		[]string{"new                        - Same as 'add'"},
		a.opAddTask,
	)
	a.addOperation("x",
		[]string{"x                          - Toggle a task's complete flag on/off"},
		a.opToggleTaskComplete,
	)
	a.addOperation("done",
		[]string{"done                       - The same as 'x'"},
		a.opToggleTaskComplete,
	)
	a.addOperation("archive",
		[]string{"archive [id1 id2 ...]      - Archive completed tasks"},
		a.opArchiveTasks,
	)
	a.addOperation("--reinit",
		[]string{"--reinit                   - Reset all Configuration Settings"},
		func(args []string) int {
			a.initializeConfig()
			return 0
		},
	)
	a.addOperation("-h",
		[]string{"-h                         - Print this message"},
		a.opPrintUsage,
	)
	a.addOperation("help",
		[]string{"help                       - Print this message"},
		a.opPrintUsage,
	)
	a.addOperation("--h",
		[]string{"--h                        - Print this message"},
		a.opPrintUsage,
	)
	a.directory = a.config.Get("directory")
	a.fileTodo = a.config.Get("todofile")
	a.fileDone = a.config.Get("donefile")
	a.fileReport = a.config.Get("reportfile")
}

func (a *AppState) initializeConfig() {
	fmt.Println("Initializing " + a.Name)
	for {
		var add string
		if a.directory != "" {
			add = " (" + a.directory + ")"
		}
		fmt.Println("Path to todo.txt" + add + ":")
		var resp string
		fmt.Scanln(&resp)
		if resp == "" && a.directory != "" {
			resp = a.directory
		}
		if resp != "" {
			if !strings.HasSuffix(resp, "/") {
				resp = resp + "/"
			}
			fmt.Println("Setting todo.txt directory to: " + resp)
			a.config.Set("directory", resp)
			break
		}
	}
	a.config.Set("todofile", "todo.txt")
	a.config.Set("donefile", "done.txt")
	a.config.Set("reportfile", "report.txt")
}