package saggytrousers 

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
	// "git.gabbott.dev/george/excelize/v2"
	xl "anyxcelize"
)

/* Public Functions */
/* func GetString(prompt string) string
 * func GetInt(prompt string) int
 * func GetFloat64(prompt string) float64
 * func SelectSheet(file *xl.File, sheet string) string
 * func SelectHeader(f *xl.File, sheet, choice string, exact bool) int
 * func UserSelectHeader(f *xl.File, sheet string) ([]string, int)
 * func ChooseFromHeader(header []string) int
 * func ChooseFromHeaderPrompt(header []string, prompt string) int 
 *
 */

 func longest(choices []string) int {
	 l := 0
	 for _, v := range choices {
		 if len(v) > l {
			 l = len(v)
		 }
	 }
	 return l
 }

// If prompt == "", then prompt with "The options are: \n".
func selectIndexFromArray(choices []string, prompt string, eachOnNewline bool) int {
	Log(false, "selectIndexFromArray: choices %v; see below for prompt; eachOnNewline %v\n", choices, eachOnNewline)
	length := longest(choices)
	Log(true, "%v\n", prompt)
	for i, v := range choices {
		var separator string
		if eachOnNewline {
			separator = "\n"
		} else if i != 0 && i % 3 == 0 {
			separator = "\n\t"
		} else {
			separator = "\t"
		}
		fmt.Printf("%s%2d: %-*s", separator, i + 1, length, v)
	}

	var answer int 
	Log(true, "\nWhat is your selection: ")
	for {
		answer = GetInt("")
		Log(false, "selectIndexFromArray: user inputted %v (one-indexed)\n", answer)
		if answer < 1 || answer > len(choices) { // one-indexed
			Log(true, "Bad selection, try again: ")
			continue
		}
		break
	}

	Log(false, "selectIndexFromArray: returning %v (zero-indexed)\n", answer - 1)
	return answer - 1 // zero-indexed
}

func SelectIndexFromArray(choices []string, prompt string, eachOnNewline bool) int {
	return selectIndexFromArray(choices, prompt, eachOnNewline)
}

// Prompt the user with `prompt`, and then return the input. 
func GetString(prompt string) string {
	var reader = bufio.NewReader(os.Stdin)

	fmt.Printf("%s", prompt)
	answer, _ := reader.ReadString('\n')

	Log(false, "GetString returned %v\n", answer)
	return answer
}

// Prompt the user with `prompt`, and then return the integer the user 
// enters. If the user does not enter an integer it re-prompts until he does. 
func GetInt(prompt string) int {
	var reader = bufio.NewReader(os.Stdin)

	fmt.Printf("%s", prompt)
	for {
		answer, _ := reader.ReadString('\n')
		answer = strings.TrimRight(answer, "\n")
		answer = strings.TrimRight(answer, " ")

		i, err := strconv.Atoi(answer)
		if err != nil {
			fmt.Printf("Invalid number, please re-enter: ")
			continue 
		}

		Log(false, "GetInt returned %v\n", i)
		return i 
	}
}

func GetFloat64(prompt string) float64 {
	var reader = bufio.NewReader(os.Stdin)

	fmt.Printf("%s", prompt)
	for {
		answer, _ := reader.ReadString('\n')
		answer = strings.TrimRight(answer, "\n")
		answer = strings.TrimRight(answer, " ")

		i, err := strconv.ParseFloat(answer, 64)
		if err != nil {
			fmt.Printf("Invalid number, please re-enter: ")
			continue 
		}

		return i 
	}
}

// Given a list of sheets, prompt the user to select a sheet and return that
// which was selected.
func userSelectSheet(sheets []string) string {
	var selected string
	
	fmt.Println("Please select the sheet that is to be used.")
	selectedIdx := selectIndexFromArray(sheets, "", /* each on newline: */ false)
	selected = sheets[selectedIdx]

	return selected
}

// Takes a potentially sheet name, and returns that sheet if it is a valid name 
// or prompt the user to select a valid sheet name if it is not. 
func SelectSheet(file *xl.File, sheet string) string {
	sheetsMap := file.GetSheetMap()
	sheets := GetMapValues(sheetsMap)

	// If the passed `sheet` is correct, return it.
	if InSlice(sheets, sheet) {
		return sheet
	}

	// If there is only one sheet in the file, return that. 
	if len(sheets) == 1 {
		// fmt.Printf("Only one sheet: selecting [%s]", sheets[0])
		return sheets[0]
	}

	return userSelectSheet(sheets)
}

// Takes a potential choice from the header row. Returns the index of the
// choice if it is valid, else prompts the user similarly to UserSelectHeader.
func SelectHeader(f *xl.File, sheet, choice string, exact bool) int {
	rows, err := f.Rows(sheet)
	if err != nil {
		fmt.Printf("SelectHeader(sheet: %s, choice: %s, exact: %v: could not get rows to get the header\n", sheet, choice, exact)
		os.Exit(-1)
	}
	rows.Next()
	header, err := rows.Columns()
	if err != nil {
		fmt.Println("SelectHeader: could not get the header.")
		os.Exit(-1)
	}

	index := Locate(header, choice)
	if index != -1 {
		return index
	}

	// If cannot find, let the user select
	fmt.Println("\nPlease select the correct field.")
	index = selectIndexFromArray(header, "", /* each on new line: */ false)

	return index
}

// Have the user select a column from the header, and return both the header 
// and the index of the selected value.
func UserSelectHeader(f *xl.File, sheet string) ([]string, int) {
	rows, err := f.Rows(sheet)
	if err != nil {
		fmt.Println("Could not get rows to get the header.")
		os.Exit(-1)
	}

	rows.Next()
	header, err := rows.Columns()
	if err != nil {
		fmt.Println("Could not get the header.")
		os.Exit(-1)
	}

	fmt.Println("\nPlease select the correct field.")
	index := selectIndexFromArray(header, "Please select the correct field: ", /* each on new line: */ false)
	return header, index
}

func ChooseFromHeader(header []string) int {
	return selectIndexFromArray(header, "", /* each on new line: */ false)
}

func ChooseFromHeaderPrompt(header []string, prompt string) int {
	return selectIndexFromArray(header, prompt, /* each on new line: */ false)
}