package util

import (
	"bufio"
	"errors"
	"fmt"
	"os"
	"sort"
	"strings"
	"time"

	timertxt "git.bullercodeworks.com/brian/go-timertxt"
	"github.com/spf13/viper"
)

const (
	ROUND_UP     = 1
	ROUND_EITHER = 0
	ROUND_DOWN   = -1
)

func PromptUser(text string) string {
	var resp string
	fmt.Println(text)
	scanner := bufio.NewScanner(os.Stdin)
	if scanner.Scan() {
		resp = scanner.Text()
	}
	return resp
}

// TimerToString takes a TimeEntry and gives a nicely formatted string
func TimerToString(t *timertxt.Timer) string {
	var ret string
	var end string
	if t.StartsToday() {
		ret = t.StartDate.Format("15:04 - ")
		end = "**:**"
	} else {
		ret = t.StartDate.Format("2006/01/02 15:04:05 - ")
		end = "**:**:**"
	}
	if !t.FinishDate.IsZero() {
		if t.EndsToday() {
			end = t.FinishDate.Format("15:04")
		} else {
			end = t.FinishDate.Format("2006/01/02 15:04:05")
		}
	}
	ret += end
	if len(t.Contexts) > 0 {
		ret += " " + fmt.Sprint(t.Contexts)
	}
	if len(t.Projects) > 0 {
		ret += " " + fmt.Sprint(t.Projects)
	}
	if len(t.AdditionalTags) > 0 {
		ret += " [ "
		for k, v := range t.AdditionalTags {
			ret += k + ":" + v + " "
		}
		ret += "]"
	}
	return ret
}

func Round(dur time.Duration) time.Duration {
	roundDur := GetRoundToDuration()
	wrk := dur.Round(roundDur)
	switch GetRoundDirection() {
	case ROUND_UP:
		if wrk < dur {
			return wrk + roundDur
		}
	case ROUND_DOWN:
		if wrk > dur {
			return wrk - roundDur
		}
	}
	return wrk
}

func GetRoundDirection() int {
	dir := viper.GetString("round")
	switch dir {
	case "up":
		return ROUND_UP
	case "down":
		return ROUND_DOWN
	default:
		return ROUND_EITHER
	}
}

func GetRoundToDuration() time.Duration {
	var dur time.Duration
	dur, _ = time.ParseDuration(viper.GetString("roundto"))
	return dur
}

func DurationToDecimal(dur time.Duration) float64 {
	mins := dur.Minutes() - (dur.Hours() * 60)
	return dur.Hours() + (mins / 60)
}
func AddDurations(dur1, dur2 time.Duration) time.Duration {
	return time.Duration(int64(dur1) + int64(dur2))
}
func SubDurations(dur1, dur2 time.Duration) time.Duration {
	return time.Duration(int64(dur1) - int64(dur2))
}

// GetContextsFromSlice pulls all '@' (contexts) out of the
// string slice and return those contexts and the remaining
// strings from the slice
func GetContextsFromSlice(args []string) ([]string, []string) {
	return SplitSlice(args, func(v string) bool {
		return strings.HasPrefix(v, "@")
	})
}

// GetProjectsFromSlice pulls all '+' (projects) out of the
// string slice and return those projects and the remaining
// strings from the slice
func GetProjectsFromSlice(args []string) ([]string, []string) {
	return SplitSlice(args, func(v string) bool {
		return strings.HasPrefix(v, "+")
	})
}

// GetAdditionalTagsFromSlice pulls all '*:*' (tags) out of the
// string slice and returns those tags and the remaining
// strings from the slice
func GetAdditionalTagsFromSlice(args []string) ([]string, []string) {
	return SplitSlice(args, func(v string) bool {
		return strings.Contains(v, ":")
	})
}

func SplitSlice(args []string, predicate func(string) bool) ([]string, []string) {
	var rem1, rem2 []string
	for _, v := range args {
		if predicate(v) {
			rem1 = append(rem1, v)
		} else {
			rem2 = append(rem2, v)
		}
	}
	return rem1, rem2
}

func ParseFuzzyTime(t string) (time.Time, error) {
	var ret time.Time
	var err error
	for i := range fuzzyFormats {
		ret, err = time.Parse(fuzzyFormats[i], t)
		if err == nil {
			// Make sure it's in the local timezone
			tz := time.Now().Format("Z07:00")
			t = ret.Format("2006-01-02T15:04:05") + tz
			if ret, err = time.Parse(time.RFC3339, t); err != nil {
				return ret, err
			}
			// Check for zero on year/mo/day
			if ret.Year() == 0 && ret.Month() == time.January && ret.Day() == 1 {
				ret = ret.AddDate(time.Now().Year(), int(time.Now().Month())-1, time.Now().Day()-1)
			}
			return ret, nil
		}
	}
	return time.Time{}, errors.New("Unable to parse time: " + t)
}

var fuzzyFormats = []string{
	"1504",
	"15:04", // Kitchen, 24hr
	time.Kitchen,
	time.RFC3339,
	"2006-01-02T15:04:05", // RFC3339 without timezone
	"2006-01-02T15:04",    // RFC3339 without seconds or timezone
	time.Stamp,
	"02 Jan 06 15:04:05", // RFC822 with second
	time.RFC822,
	"01/02/2006 15:04",    // U.S. Format
	"01/02/2006 15:04:05", // U.S. Format with seconds
	"01/02/06 15:04",      // U.S. Format, short year
	"01/02/06 15:04:05",   // U.S. Format, short year, with seconds
	"2006-01-02",
	"2006-01-02 15:04",
	"2006-01-02 15:04:05",
	"20060102",
	"20060102 15:04",
	"20060102 15:04:05",
	"20060102 1504",
	"20060102 150405",
	"20060102T15:04",
	"20060102T15:04:05",
	"20060102T1504",
	"20060102T150405",
}

func TimerToFriendlyString(t *timertxt.Timer) string {
	var start, end, contexts, projects, tags string
	start = t.StartDate.Format(FriendlyFormatForTime(t.StartDate))
	if t.FinishDate.IsZero() {
		end = "**:**"
	} else {
		end = t.FinishDate.Format(FriendlyFormatForTime(t.FinishDate))
	}
	for _, v := range t.Contexts {
		contexts += "@" + v + " "
	}
	for _, v := range t.Projects {
		projects += "+" + v + " "
	}
	for k, v := range t.AdditionalTags {
		tags = fmt.Sprintf("%s%s:%s ", tags, k, v)
	}
	var dur time.Duration
	if t.FinishDate.IsZero() {
		dur = time.Now().Sub(t.StartDate)
	} else {
		dur = t.FinishDate.Sub(t.StartDate)
	}
	dur = Round(dur)
	return fmt.Sprintf("% 2d. %s - %s [ %s] [ %s] [ %s] %s ( %.2f )", t.Id, start, end, contexts, projects, tags, t.Notes, DurationToDecimal(dur))
}

func FriendlyFormatForTime(t time.Time) string {
	nowTime := time.Now()
	if t.Year() != nowTime.Year() || t.Month() != nowTime.Month() {
		return "2006-01-02 15:04"
	} else if t.Day() != nowTime.Day() {
		return "01/02 15:04"
	}
	return "15:04"
}

// TimeToFriendlyString returns an easier to read version of the time
// giving enough details that the user should be fine inferring the rest
func TimeToFriendlyString(t time.Time) string {
	return t.Format(FriendlyFormatForTime(t))
}

func SinceToString(tm time.Time) string {
	return DiffToString(tm, time.Now())
}

func DiffToString(tm1, tm2 time.Time) string {
	ret := ""
	yr, mo, dy, hr, mn, sc := Diff(tm1, tm2)
	higher := false

	if yr > 0 {
		ret += fmt.Sprintf("%4dy ", yr)
		higher = true
	}
	if mo > 0 || higher {
		ret += fmt.Sprintf("%2dm ", mo)
		higher = true
	}
	if dy > 0 || higher {
		ret += fmt.Sprintf("%2dd ", dy)
		higher = true
	}
	if hr > 0 || higher {
		ret += fmt.Sprintf("%2dh ", hr)
		higher = true
	}
	if mn > 0 || higher {
		ret += fmt.Sprintf("%2dm ", mn)
		higher = true
	}
	if sc > 0 || higher {
		ret += fmt.Sprintf("%2ds", sc)
	}
	return ret
}

func PadRight(st string, l int) string {
	for len(st) < l {
		st = st + " "
	}
	return st
}

func PadLeft(st string, l int) string {
	for len(st) < l {
		st = " " + st
	}
	return st
}

func Diff(a, b time.Time) (year, month, day, hour, min, sec int) {
	if a.Location() != b.Location() {
		b = b.In(a.Location())
	}
	if a.After(b) {
		a, b = b, a
	}
	y1, M1, d1 := a.Date()
	y2, M2, d2 := b.Date()

	h1, m1, s1 := a.Clock()
	h2, m2, s2 := b.Clock()

	year = int(y2 - y1)
	month = int(M2 - M1)
	day = int(d2 - d1)
	hour = int(h2 - h1)
	min = int(m2 - m1)
	sec = int(s2 - s1)

	// Normalize negative values
	if sec < 0 {
		sec += 60
		min--
	}
	if min < 0 {
		min += 60
		hour--
	}
	if hour < 0 {
		hour += 24
		day--
	}
	if day < 0 {
		// days in month:
		t := time.Date(y1, M1, 32, 0, 0, 0, 0, time.UTC)
		day += 32 - t.Day()
		month--
	}
	if month < 0 {
		month += 12
		year--
	}

	return
}

func BeginningOfDay() time.Time {
	now := time.Now()
	return time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, now.Location())
}

func BeginningOfWeek() time.Time {
	now := time.Now()
	t := time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, now.Location())
	weekday := int(t.Weekday())
	return t.AddDate(0, 0, -weekday)
}

func BeginningOfMonth() time.Time {
	now := time.Now()
	return time.Date(now.Year(), now.Month(), 1, 0, 0, 0, 0, now.Location())
}

func BuildFilterFromArgs(args []string) func(*timertxt.Timer) bool {
	start := time.Time{}
	end := time.Now()
	var contextFilters []string
	var projectFilters []string
	var allFilters []func(timertxt.Timer) bool
	if len(args) > 0 {
		contextFilters, args = GetContextsFromSlice(args)
		projectFilters, args = GetProjectsFromSlice(args)
	}
	if len(args) > 0 {
		var err error
		if start, err = ParseFuzzyTime(args[0]); err != nil {
			y, m, d := time.Now().Date()
			start = time.Date(y, m, d, 0, 0, 0, 0, time.Now().Location())
		} else {
			args = args[1:]
		}
		if len(args) > 0 {
			if end, err = ParseFuzzyTime(args[0]); err != nil {
				y, m, d := time.Now().Date()
				end = time.Date(y, m, d, 23, 59, 59, 0, time.Now().Location())
			} else {
				args = args[1:]
			}
		}
	}
	allFilters = append(allFilters, func(t timertxt.Timer) bool {
		if t.StartDate.Before(end) && t.StartDate.After(start) {
			return true
		}
		if t.FinishDate.Before(end) && t.FinishDate.After(start) {
			return true
		}
		return false
	})
	if len(contextFilters) > 0 {
		allFilters = append(allFilters, func(t timertxt.Timer) bool {
			for _, v := range contextFilters {
				v = strings.TrimPrefix(v, "@")
				if !t.HasContext(v) {
					return false
				}
			}
			return true
		})
	}
	if len(projectFilters) > 0 {
		allFilters = append(allFilters, func(t timertxt.Timer) bool {
			for _, v := range projectFilters {
				v = strings.TrimPrefix(v, "+")
				if !t.HasProject(v) {
					return false
				}
			}
			return true
		})
	}
	doFilters := func(t *timertxt.Timer) bool {
		for _, v := range allFilters {
			if !v(*t) {
				return false
			}
		}
		// If we made it all the way down here, it matches
		return true
	}
	return doFilters
}

func SortedTagKeyList(m map[string]string) []string {
	var ret []string
	for k := range m {
		ret = append(ret, k)
	}
	sort.Strings(ret)
	return ret
}

func StringSliceContains(sl []string, val string) bool {
	for i := range sl {
		if sl[i] == val {
			return true
		}
	}
	return false
}