package main

import (
	"encoding/json"
	"fmt"
	"io/ioutil"
	"os"
	"time"

	"github.com/0xAX/notificator"
	"github.com/fatih/color"
)

const (
	defaultDateTimeFmt = "2006-01-02 15:04"
)

type State int

func (s State) String() string {
	switch s {
	case RUNNING:
		return "RUNNING"
	case BREAKING:
		return "BREAKING"
	case COMPLETE:
		return "COMPLETE"
	case PAUSED:
		return "PAUSED"
	}
	return ""
}

const (
	RUNNING State = iota + 1
	BREAKING
	COMPLETE
	PAUSED
)

// Wheel keeps track of an ASCII spinner
type Wheel int

func (w *Wheel) String() string {
	switch int(*w) {
	case 0:
		*w++
		return "|"
	case 1:
		*w++
		return "/"
	case 2:
		*w++
		return "-"
	case 3:
		*w = 0
		return "\\"
	}
	return ""
}

// Config represents user preferences
type Config struct {
	Colors      map[string]*color.Color
	DateTimeFmt string
}

var colorMap = map[string]*color.Color{
	"black":     color.New(color.FgBlack),
	"hiblack":   color.New(color.FgHiBlack),
	"blue":      color.New(color.FgBlue),
	"hiblue":    color.New(color.FgHiBlue),
	"cyan":      color.New(color.FgCyan),
	"hicyan":    color.New(color.FgHiCyan),
	"green":     color.New(color.FgGreen),
	"higreen":   color.New(color.FgHiGreen),
	"magenta":   color.New(color.FgMagenta),
	"himagenta": color.New(color.FgHiMagenta),
	"red":       color.New(color.FgRed),
	"hired":     color.New(color.FgHiRed),
	"white":     color.New(color.FgWhite),
	"hiwrite":   color.New(color.FgHiWhite),
	"yellow":    color.New(color.FgYellow),
	"hiyellow":  color.New(color.FgHiYellow),
}

func (c *Config) UnmarshalJSON(raw []byte) error {
	config := &struct {
		Colors      map[string]string `json:"colors"`
		DateTimeFmt string            `json:"datetimefmt"`
	}{}
	err := json.Unmarshal(raw, config)
	if err != nil {
		return err
	}
	for key, name := range config.Colors {
		if color, ok := colorMap[name]; ok {
			c.Colors[key] = color
		} else {
			return fmt.Errorf("bad color choice: %s", name)
		}
	}
	if config.DateTimeFmt != "" {
		c.DateTimeFmt = config.DateTimeFmt
	} else {
		c.DateTimeFmt = defaultDateTimeFmt
	}
	return nil
}

func NewConfig(path string) (*Config, error) {
	raw, err := ioutil.ReadFile(path)
	if err != nil {
		// Create an empty config file
		// if it does not already exist.
		if os.IsNotExist(err) {
			raw, _ := json.Marshal(map[string]*color.Color{})
			ioutil.WriteFile(path, raw, 0644)
			return NewConfig(path)
		}
		return nil, err
	}
	config := &Config{
		Colors: map[string]*color.Color{},
	}
	err = json.Unmarshal(raw, config)
	if err != nil {
		return nil, err
	}
	return config, json.Unmarshal(raw, config)
}

// Task describes some activity
type Task struct {
	ID      int    `json:"id"`
	Message string `json:"message"`
	// Array of completed pomodoros
	Pomodoros []*Pomodoro `json:"pomodoros"`
	// Free-form tags associated with this task
	Tags []string `json:"tags"`
	// Number of pomodoros for this task
	NPomodoros int `json:"n_pomodoros"`
	// Duration of each pomodoro
	Duration time.Duration `json:"duration"`
}

// ByID is a sortable array of tasks
type ByID []*Task

func (b ByID) Len() int           { return len(b) }
func (b ByID) Swap(i, j int)      { b[i], b[j] = b[j], b[i] }
func (b ByID) Less(i, j int) bool { return b[i].ID < b[j].ID }

// Pomodoro is a unit of time to spend working
// on a single task.
type Pomodoro struct {
	Start time.Time `json:"start"`
	End   time.Time `json:"end"`
}

// Duration returns the runtime of the pomodoro
func (p Pomodoro) Duration() time.Duration {
	return (p.End.Sub(p.Start))
}

// Notifier sends a system notification
type Notifier interface {
	Notify(string, string) error
}

// NoopNotifier does nothing
type NoopNotifier struct{}

func (n NoopNotifier) Notify(string, string) error { return nil }

// Xnotifier can push notifications to mac, linux and windows.
type Xnotifier struct {
	*notificator.Notificator
	iconPath string
}

func NewXnotifier(iconPath string) Notifier {
	// Write the built-in tomato icon if it
	// doesn't already exist.
	_, err := os.Stat(iconPath)
	if os.IsNotExist(err) {
		raw := MustAsset("tomato-icon.png")
		_ = ioutil.WriteFile(iconPath, raw, 0644)
	}
	return Xnotifier{
		Notificator: notificator.New(notificator.Options{}),
		iconPath:    iconPath,
	}
}

// Notify sends a notification to the OS.
func (n Xnotifier) Notify(title, body string) error {
	return n.Push(title, body, n.iconPath, notificator.UR_NORMAL)
}