// Copyright 2016 - 2022 The excelize Authors. All rights reserved. Use of
// this source code is governed by a BSD-style license that can be found in
// the LICENSE file.
//
// Package excelize providing a set of functions that allow you to write to
// and read from XLSX / XLSM / XLTM files. Supports reading and writing
// spreadsheet documents generated by Microsoft Excel™ 2007 and later. Supports
// complex components by high compatibility, and provided streaming API for
// generating or reading data from a worksheet with huge amounts of data. This
// library needs Go version 1.15 or later.

package excelize

import (
	"fmt"
	"strconv"
	"strings"
	"time"

	"github.com/xuri/nfp"
)

// supportedTokenTypes list the supported number format token types currently.
var supportedTokenTypes = []string{
	nfp.TokenTypeCurrencyLanguage,
	nfp.TokenTypeDateTimes,
	nfp.TokenTypeElapsedDateTimes,
	nfp.TokenTypeGeneral,
	nfp.TokenTypeLiteral,
	nfp.TokenSubTypeLanguageInfo,
}

// numberFormat directly maps the number format parser runtime required
// fields.
type numberFormat struct {
	section                                                                 []nfp.Section
	t                                                                       time.Time
	sectionIdx                                                              int
	isNumberic, hours, seconds                                              bool
	number                                                                  float64
	ap, afterPoint, beforePoint, localCode, result, value, valueSectionType string
}

// prepareNumberic split the number into two before and after parts by a
// decimal point.
func (nf *numberFormat) prepareNumberic(value string) {
	prec := 0
	if nf.isNumberic, prec = isNumeric(value); !nf.isNumberic {
		return
	}
	nf.beforePoint, nf.afterPoint = value[:len(value)-prec-1], value[len(value)-prec:]
}

// format provides a function to return a string parse by number format
// expression. If the given number format is not supported, this will return
// the original cell value.
func format(value, numFmt string) string {
	p := nfp.NumberFormatParser()
	nf := numberFormat{section: p.Parse(numFmt), value: value}
	nf.number, nf.valueSectionType = nf.getValueSectionType(value)
	nf.prepareNumberic(value)
	for i, section := range nf.section {
		nf.sectionIdx = i
		if section.Type != nf.valueSectionType {
			continue
		}
		switch section.Type {
		case nfp.TokenSectionPositive:
			return nf.positiveHandler()
		case nfp.TokenSectionNegative:
			return nf.negativeHandler()
		case nfp.TokenSectionZero:
			return nf.zeroHandler()
		default:
			return nf.textHandler()
		}
	}
	return value
}

// positiveHandler will be handling positive selection for a number format
// expression.
func (nf *numberFormat) positiveHandler() (result string) {
	nf.t, nf.hours, nf.seconds = timeFromExcelTime(nf.number, false), false, false
	for i, token := range nf.section[nf.sectionIdx].Items {
		if inStrSlice(supportedTokenTypes, token.TType, true) == -1 || token.TType == nfp.TokenTypeGeneral {
			result = fmt.Sprint(nf.number)
			return
		}
		if token.TType == nfp.TokenTypeCurrencyLanguage {
			if err := nf.currencyLanguageHandler(i, token); err != nil {
				result = fmt.Sprint(nf.number)
				return
			}
		}
		if token.TType == nfp.TokenTypeDateTimes {
			nf.dateTimesHandler(i, token)
		}
		if token.TType == nfp.TokenTypeElapsedDateTimes {
			nf.elapsedDateTimesHandler(token)
		}
		if token.TType == nfp.TokenTypeLiteral {
			nf.result += token.TValue
			continue
		}
	}
	result = nf.result
	return
}

// currencyLanguageHandler will be handling currency and language types tokens for a number
// format expression.
func (nf *numberFormat) currencyLanguageHandler(i int, token nfp.Token) (err error) {
	for _, part := range token.Parts {
		if inStrSlice(supportedTokenTypes, part.Token.TType, true) == -1 {
			err = ErrUnsupportedNumberFormat
			return
		}
		if nf.localCode = part.Token.TValue; nf.localCode != "409" {
			err = ErrUnsupportedNumberFormat
			return
		}
	}
	return
}

// dateTimesHandler will be handling date and times types tokens for a number
// format expression.
func (nf *numberFormat) dateTimesHandler(i int, token nfp.Token) {
	if idx := inStrSlice(nfp.AmPm, strings.ToUpper(token.TValue), false); idx != -1 {
		if nf.ap == "" {
			nextHours := nf.hoursNext(i)
			aps := strings.Split(token.TValue, "/")
			nf.ap = aps[0]
			if nextHours > 12 {
				nf.ap = aps[1]
			}
		}
		nf.result += nf.ap
		return
	}
	if strings.Contains(strings.ToUpper(token.TValue), "M") {
		l := len(token.TValue)
		if l == 1 && !nf.hours && !nf.secondsNext(i) {
			nf.result += strconv.Itoa(int(nf.t.Month()))
			return
		}
		if l == 2 && !nf.hours && !nf.secondsNext(i) {
			nf.result += fmt.Sprintf("%02d", int(nf.t.Month()))
			return
		}
		if l == 3 {
			nf.result += nf.t.Month().String()[:3]
			return
		}
		if l == 4 || l > 5 {
			nf.result += nf.t.Month().String()
			return
		}
		if l == 5 {
			nf.result += nf.t.Month().String()[:1]
			return
		}
	}
	nf.yearsHandler(i, token)
	nf.daysHandler(i, token)
	nf.hoursHandler(i, token)
	nf.minutesHandler(token)
	nf.secondsHandler(token)
}

// yearsHandler will be handling years in the date and times types tokens for a
// number format expression.
func (nf *numberFormat) yearsHandler(i int, token nfp.Token) {
	years := strings.Contains(strings.ToUpper(token.TValue), "Y")
	if years && len(token.TValue) <= 2 {
		nf.result += strconv.Itoa(nf.t.Year())[2:]
		return
	}
	if years && len(token.TValue) > 2 {
		nf.result += strconv.Itoa(nf.t.Year())
		return
	}
}

// daysHandler will be handling days in the date and times types tokens for a
// number format expression.
func (nf *numberFormat) daysHandler(i int, token nfp.Token) {
	if strings.Contains(strings.ToUpper(token.TValue), "D") {
		switch len(token.TValue) {
		case 1:
			nf.result += strconv.Itoa(nf.t.Day())
			return
		case 2:
			nf.result += fmt.Sprintf("%02d", nf.t.Day())
			return
		case 3:
			nf.result += nf.t.Weekday().String()[:3]
			return
		default:
			nf.result += nf.t.Weekday().String()
			return
		}
	}
}

// hoursHandler will be handling hours in the date and times types tokens for a
// number format expression.
func (nf *numberFormat) hoursHandler(i int, token nfp.Token) {
	nf.hours = strings.Contains(strings.ToUpper(token.TValue), "H")
	if nf.hours {
		h := nf.t.Hour()
		ap, ok := nf.apNext(i)
		if ok {
			nf.ap = ap[0]
			if h > 12 {
				h -= 12
				nf.ap = ap[1]
			}
		}
		if nf.ap != "" && nf.hoursNext(i) == -1 && h > 12 {
			h -= 12
		}
		switch len(token.TValue) {
		case 1:
			nf.result += strconv.Itoa(h)
			return
		default:
			nf.result += fmt.Sprintf("%02d", h)
			return
		}
	}
}

// minutesHandler will be handling minutes in the date and times types tokens
// for a number format expression.
func (nf *numberFormat) minutesHandler(token nfp.Token) {
	if strings.Contains(strings.ToUpper(token.TValue), "M") {
		nf.hours = false
		switch len(token.TValue) {
		case 1:
			nf.result += strconv.Itoa(nf.t.Minute())
			return
		default:
			nf.result += fmt.Sprintf("%02d", nf.t.Minute())
			return
		}
	}
}

// secondsHandler will be handling seconds in the date and times types tokens
// for a number format expression.
func (nf *numberFormat) secondsHandler(token nfp.Token) {
	nf.seconds = strings.Contains(strings.ToUpper(token.TValue), "S")
	if nf.seconds {
		switch len(token.TValue) {
		case 1:
			nf.result += strconv.Itoa(nf.t.Second())
			return
		default:
			nf.result += fmt.Sprintf("%02d", nf.t.Second())
			return
		}
	}
}

// elapsedDateTimesHandler will be handling elapsed date and times types tokens
// for a number format expression.
func (nf *numberFormat) elapsedDateTimesHandler(token nfp.Token) {
	if strings.Contains(strings.ToUpper(token.TValue), "H") {
		nf.result += fmt.Sprintf("%.f", nf.t.Sub(excel1900Epoc).Hours())
		return
	}
	if strings.Contains(strings.ToUpper(token.TValue), "M") {
		nf.result += fmt.Sprintf("%.f", nf.t.Sub(excel1900Epoc).Minutes())
		return
	}
	if strings.Contains(strings.ToUpper(token.TValue), "S") {
		nf.result += fmt.Sprintf("%.f", nf.t.Sub(excel1900Epoc).Seconds())
		return
	}
}

// hoursNext detects if a token of type hours exists after a given tokens list.
func (nf *numberFormat) hoursNext(i int) int {
	tokens := nf.section[nf.sectionIdx].Items
	for idx := i + 1; idx < len(tokens); idx++ {
		if tokens[idx].TType == nfp.TokenTypeDateTimes {
			if strings.Contains(strings.ToUpper(tokens[idx].TValue), "H") {
				t := timeFromExcelTime(nf.number, false)
				return t.Hour()
			}
		}
	}
	return -1
}

// apNext detects if a token of type AM/PM exists after a given tokens list.
func (nf *numberFormat) apNext(i int) ([]string, bool) {
	tokens := nf.section[nf.sectionIdx].Items
	for idx := i + 1; idx < len(tokens); idx++ {
		if tokens[idx].TType == nfp.TokenTypeDateTimes {
			if strings.Contains(strings.ToUpper(tokens[idx].TValue), "H") {
				return nil, false
			}
			if i := inStrSlice(nfp.AmPm, tokens[idx].TValue, false); i != -1 {
				return strings.Split(tokens[idx].TValue, "/"), true
			}
		}
	}
	return nil, false
}

// secondsNext detects if a token of type seconds exists after a given tokens
// list.
func (nf *numberFormat) secondsNext(i int) bool {
	tokens := nf.section[nf.sectionIdx].Items
	for idx := i + 1; idx < len(tokens); idx++ {
		if tokens[idx].TType == nfp.TokenTypeDateTimes {
			return strings.Contains(strings.ToUpper(tokens[idx].TValue), "S")
		}
	}
	return false
}

// negativeHandler will be handling negative selection for a number format
// expression.
func (nf *numberFormat) negativeHandler() string {
	return fmt.Sprint(nf.number)
}

// zeroHandler will be handling zero selection for a number format expression.
func (nf *numberFormat) zeroHandler() string {
	return fmt.Sprint(nf.number)
}

// textHandler will be handling text selection for a number format expression.
func (nf *numberFormat) textHandler() string {
	return fmt.Sprint(nf.value)
}

// getValueSectionType returns its applicable number format expression section
// based on the given value.
func (nf *numberFormat) getValueSectionType(value string) (float64, string) {
	number, err := strconv.ParseFloat(value, 64)
	if err != nil {
		return number, nfp.TokenSectionText
	}
	if number > 0 {
		return number, nfp.TokenSectionPositive
	}
	if number < 0 {
		return number, nfp.TokenSectionNegative
	}
	return number, nfp.TokenSectionZero
}