package cmd

import (
	"fmt"
	"regexp"
	"strings"
	"text/template"
)

var tplFuncs = template.FuncMap{
	"map":       tplMap,
	"cat":       tplCat,
	"split":     tplSplit,
	"join":      tplJoin,
	"under":     tplUnder,
	"varPrefix": tplVarPrefix,
	"repeat":    tplRepeat,
	"indent":    tplIndent,
	"add":       tplAdd,
	"inc":       tplInc,
	"sub":       tplSub,
	"dec":       tplDec,
	"mult":      tplMult,
	"camel":     tplCamel,
}

func tplMap(vals ...any) (map[string]any, error) {
	if len(vals)%2 != 0 {
		return nil, fmt.Errorf("missing value, need one key and one value per kv pair")
	}

	m := make(map[string]any)
	for i := 0; i < len(vals); i += 2 {
		m[vals[i].(string)] = vals[i+1]
	}
	return m, nil
}

func tplCat(strs ...string) string {
	return strings.Join(strs, "")
}

func tplSplit(s string, sep string) []string {
	return strings.Split(s, sep)
}

func tplJoin(strs []string, sep string) string {
	return strings.Join(strs, sep)
}

func tplUnder(s string) string {
	// Remove all characters that are not alphanumeric or spaces or underscores
	s = regexp.MustCompile("[^a-zA-Z0-9_ -]+").ReplaceAllString(s, "")

	// Replace all spaces with underscores
	s = strings.ReplaceAll(s, " ", "_")

	// Replace all dashes with underscores
	s = strings.ReplaceAll(s, "-", "_")

	// Convert to lowercase
	s = strings.ToLower(s)

	return s
}

func tplVarPrefix(s string) string {
	if s == "" {
		return ""
	}

	return tplUnder(s) + "_"
}

func tplRepeat(s string, n int) string {
	return strings.Repeat(s, n)
}

func tplIndent(n int) string {
	return tplRepeat(" ", n)
}

func tplAdd(a, b int) int {
	return a + b
}

func tplInc(i int) int {
	return tplAdd(i, 1)
}

func tplSub(a, b int) int {
	return a - b
}

func tplDec(i int) int {
	return tplSub(i, 1)
}

func tplMult(a, b int) int {
	return a * b
}

func tplCamel(s string) string {
	// Remove all characters that are not alphanumeric or spaces or underscores
	s = regexp.MustCompile("[^a-zA-Z0-9_ -]+").ReplaceAllString(s, "")

	// Replace all underscores with spaces
	s = strings.ReplaceAll(s, "_", " ")

	// Replace all dashes with spaces
	s = strings.ReplaceAll(s, "-", " ")

	// Title case s
	words := strings.Split(s, " ")
	for i, word := range words {
		words[i] = strings.ToTitle(word)
	}

	// Join words
	s = strings.Join(words, "")

	return s
}