" banana.vim - Convert Base Banana (https://git.lattuga.net/itec/banana) and back
" T4 - totem4@tropici.net
" Version: 0.1

if exists("g:autoloaded_Banana") || &cp
	finish
endif

let g:autoloaded_Banana= 1

fun! banana#Enc() range
	call s:ReplSel(s:Dec2Ban(s:GetSel()))
endfun!

fun! banana#EncLine()
	call setline('.', substitute(getline('.'), '\d\d*', '\=toupper(s:Doban(submatch(0)))','g'))
endfun!

fun! banana#Dec() range
		call s:ReplSel(s:Ban2Dec(s:GetSel()))
endfun!

fun! banana#DecLine()
	call setline('.', substitute(getline('.'), '\C\u\u*', '\=s:Unban(tolower(submatch(0)))','g'))
endfun!

let s:dictionary = [['b', 'c', 'd', 'f', 'g', 'l', 'm', 'n', 'p', 'r', 's', 't', 'v', 'z'], ['a', 'e', 'i', 'o', 'u']]
let s:numdict = len(s:dictionary)

fun! s:Doban(num)
	let l:v = a:num
	let l:st = ''
	let l:l = 0

	let l:i = (s:numdict - 1) % s:numdict

	while ! (l:v == 0 && l:i == (s:numdict -1) % s:numdict && l:l >= 0)
		let l:r = l:v % len(s:dictionary[l:i])
		let l:v = l:v / len(s:dictionary[l:i])
		let l:st = s:dictionary[l:i][l:r] . l:st
		let l:i = abs((l:i - 1) % s:numdict)
		let l:l = l:l + 1
	endwhile
	return l:st
endfun!

fun! s:Unban(ban)
	if ! s:IsBanana(a:ban)
		return toupper(a:ban)
	endif

	let l:v = 0
	for l:i in range(len(a:ban))

		let l:r = (s:numdict + l:i) % s:numdict
		let l:p = index(s:dictionary[l:r],a:ban[l:i])

		let l:v = l:v * len(s:dictionary[l:r]) + l:p
	endfor

	return l:v
endfun!

fun! s:IsBanana(ban)
	if (len(a:ban) % s:numdict) != 0
		return 0
	endif

	for l:i in range(len(a:ban))
		let l:r = (s:numdict + l:i) % s:numdict
		if index(s:dictionary[l:r],a:ban[l:i]) == -1
			return 0
		endif
	endfor

	return 1
endfun!

fun! s:GetSel()
	let [l:lstart, l:cstart] = getcharpos("'<")[1:2]
	let [l:lend, l:cend] = getcharpos("'>")[1:2]
	let l:lines = getline(l:lstart, l:lend)
	if len(l:lines) == 0
		return ''
	endif
	let l:lines[-1] = l:lines[-1][: l:cend - (&selection == 'inclusive' ? 1 : 2)]
	let l:lines[0] = l:lines[0][l:cstart - 1:]
	return join(l:lines, "\n")
endfun!

fun! s:ReplSel(str)
	let [l:lstart, l:cstart] = getcharpos("'<")[1:2]
	let [l:lend, l:cend] = getcharpos("'>")[1:2]
	let l:lines = getline(l:lstart, l:lend)
	let l:new_str = slice(l:lines[0],0,l:cstart - 1) . a:str . l:lines[-1][l:cend:]
	let l:new_str_lst = split(l:new_str,'\n')
	call setline(l:lstart ,l:new_str_lst)
	call setcursorcharpos(lstart, cstart)
endfun!

fun! s:Dec2Ban(text)
	return substitute(a:text, '\d\d*', '\=toupper(s:Doban(submatch(0)))', 'g')
endfun!

fun! s:Ban2Dec(text)
	return substitute(a:text, '\C\u\u*', '\=s:Unban(tolower(submatch(0)))', 'g')
endfun!