#!/usr/bin/env luajit

-- Read the README file for what this is all about.  If there is no README or similar, then you can find the link to the source below.

local lcmark = require("lcmark")	-- https://github.com/jgm/lcmark



-- Some global data.
local globalData = {
    ['_'] = ' ', ['dlr'] = '$', ['karenpurple'] = '#8800ff',
    favicon = 'nYAW_icon.png', logo = 'nYAW.png', header = '', --menu = '',
    history = '',  footer = 'Powered by <a href="https://sledjhamr.org/cgit/notYetAnotherWiki/about/">notYetAnotherWiki</a> version 0.0. &nbsp;',
}
local Sites, Files, Subs = {}, {}, {}



-- Useful functions, part 0.

-- A simple table.subtable = subtable wont work, you end up with a reference so that changes to the later get applaid to the former.
local copyTable = function(t, strip)
    local argh = {}
    for l, y in ipairs(t) do	if (l ~= y.name) and strip then table.insert(argh, y) end	end
    return argh
end


-- String together the bits array into a path string.
local stringBits = function(l)
    local bits = {}
    local last = 1
    for j = 1, #l do
	if '/' == string.sub(l, j, j) then
	    table.insert(bits, string.sub(l, last, j - 1))
	    last = j + 1
	end
    end
    return bits, string.sub(l, last)
end



-- Actually start doing things.

-- Scan the subdirectories looking for .md files.
local directory = arg[1]
if nil == directory then directory = '.' end
if '.' ~= directory then
    for l in io.popen('find . -name "*.md" -type f,l -printf "%P\n"'):lines() do
	Files[string.gsub(l, '%.md$', '')] = {}
    end
end
-- Can add in a distant directory to, for putting it's results in the current directory.
for l in io.popen('find ' .. directory .. ' -name "*.md" -type f,l -printf "%P\n"'):lines() do
    local n = string.gsub(l, '%.md$', '')
    if nil == Files[n] then Files[n] = {} end
end

-- Gotta figure out all the files and subs first.  File and sub metadata comes along for the ride.
Subs[''] = {files = {}, subs = {}, bits = {}}
for name, file in pairs(Files) do
    local bitter, path = '', ''
    local bits, bit = stringBits(name)
    local ln = #bits

    -- Go through our bits, construct Subs with bits.
    Files[name].bits = bits
    Files[name].bit = bit
    if ln > 0 then bitter = bits[1] end
    if '' ~= bitter then Subs[''].subs[bitter] = bitter end	-- "bitter end" was entirely by accident, I'm keeping it.  B-)
    for i, d in ipairs(bits) do
	if '' ~= path then path = path .. '/' end
	path = path .. d
	if nil == Subs[path]	then Subs[path] = {files = {}, subs = {}} end
	if i < ln 		then Subs[path].subs[bits[i + 1]] = bits[i + 1] end
	Subs[path].bits = copyTable(bits, true)
	if i < ln 		then table.remove(Subs[path].bits, #bits) end
    end

    -- Start the file parsing here, coz we need it's metadata.
    print('Parsing ' .. name .. '.md')
    local h = io.open(name  .. '.md', 'r')
-- TODO - should bail here on error?
    if nil ~= h then file.cm = h:read('*a') ; h:close() else print('oops! No such name ' .. name) end
    -- Convert the CommonMark to HTML, including the metadata.
    local body, metadata, err = lcmark.convert(file.cm, "html", {smart = true, yaml_metadata = true, columns = 0})
    if    nil == body then print('oops! ' .. err)
    elseif '' == body then
	-- This is a metadata only file, no content, stash the matadata in it's directory.
	Subs[path].metadata = metadata
	Files[name] = nil
    else
	-- Ordinary md file, stash it's metadata and parsed body.
	file.metadata = metadata
	file.body = body
	table.insert(Subs[path].files, bit)
    end
end



-- These functions assume the above file and sub scan has completed.

-- Which page in this directory should we show?
local whichPage = function(f)
    local fl = ''
    if (nil ~= Subs[f]) then
	if 1 == #(Subs[f].files) then	fl = Subs[f].files[1] .. '.HTML' else
	    -- Standard files to search for.
	    for i, v in ipairs{'README', 'readme', 'INDEX', 'index'} do
		for j, w in ipairs(Subs[f].files) do
		    if v == w then
			print('FOUND ' .. v .. '.HTML')
			fl = v .. '.HTML'
			break
		    end
		end
		if '' ~= fl then break end
	    end
	end
    end
    return fl
end


-- Calculate a link from the source directory to the destination directory.
local linkFrom = function(source, dest)
    local depth = 0
    local link = ''
    if source ~= dest then
	for i, v in ipairs(Subs[source].bits) do
	    if v ~= Subs[dest].bits[i] then
		depth = i
		break
	    end
	end
	depth = #(Subs[source].bits) - depth
	depth = depth + 1
	link = string.rep('../', depth)
	if (0 == depth) or (depth > #(Subs[dest].bits)) then
	    for i, v in ipairs(Subs[dest].bits) do
		if i >= depth then
		    if '' ~= link then link = link .. '/' end
		    link = link .. Subs[dest].bits[i]
		end
	    end
	end
    end
    return link
end



-- More of this actually doing things nonsense.

-- Loop through the files we found and actually create their HTML files.
for name, file in pairs(Files) do
    local path, result = '', ''
    local body, metadata = Files[name].body, Files[name].metadata
    local bits, bit = Files[name].bits, Files[name].bit
    local ln = #bits

    path = table.concat(bits, '/', 1, ln)

    if '' ~= body then
    -- Continue the parsing and conversion.  Start by turning our parsed body into something the lcmark template system can grock.
	local bod, err = lcmark.compile_template(body)
	if nil == bod then print('oops! ' .. err) else
	    local templateFile = metadata.template
	    if nil == templateFile then templateFile = 'default' end
	    file.template = templateFile .. '.template'
	end

	-- Copy any metadata found in parent directories.
	local pth = ''
	for i, d in ipairs(bits) do
	    if '' ~= pth then pth = pth .. '/' end
	    pth = pth .. d
	    if nil ~= Subs[pth] then
		if nil ~= Subs[pth].metadata then
		    for m, x in pairs(Subs[pth].metadata) do
			if nil == metadata[m] then
			    metadata[m] = x
			end
		    end
		end
	    end
	end
	-- Root directory needs to be handled separately, for now.
	if nil ~= Subs[''].metadata then
	    for	m, x in pairs(Subs[''].metadata)	do if nil == metadata[m] then metadata[m] = x end end
	end

	for		m, x in pairs(globalData)		do if nil == metadata[m] then metadata[m] = x end end

	-- Inherit these images from most recent parent directory that defines them.
	for n, y in ipairs{'favicon', 'logo'} do
	    local pith = ''
	    if nil ~= metadata[y] then
		local pth = ''
		for m, x in ipairs(bits) do
		    if '' ~= pth then pth = pth .. '/' end
		    pth = pth .. x
		    if (nil ~= Subs[pth].metadata) and (nil ~= Subs[pth].metadata[y]) then pith = pth end
		end
		if ('' == pith) and (nil ~= Subs[''].metadata) and (nil ~= Subs[''].metadata[y]) then pith = pth end
		if '' == pith then	metadata[y] = linkFrom(path, pith) .. globalData[y]
		else			metadata[y] = linkFrom(path, pith) .. metadata[y]
		end
	    end
	end

	-- Figure out this pages header links.
	metadata.header = ''
	local pth = ''
	for i, f in pairs(Subs[path].subs) do
	    local fl = ''
	    if '' ~= path then
		if '' ~= pth then pth = pth .. '/' end
		pth = pth .. f
		fl = whichPage(pth)
	    else
		fl = whichPage(f)
	    end

--	    if '' == fl then
--		metadata.header = metadata.header .. f .. '</a> &nbsp; '
--	    else
		metadata.header = metadata.header .. '<a href="' .. f .. '/' .. fl .. '">' .. f .. '</a> &nbsp; '
--	    end
	end

	-- Figure out this pages menu links.
	metadata.menu = ''
	if nil ~= Subs[path].files then table.sort(Subs[path].files) end
	for i, f in ipairs(Subs[path].files) do
	    if name == f then
		metadata.menu = metadata.menu .. '<p>' .. f .. '</p>'
	    else
		metadata.menu = metadata.menu .. '<p><a href="' .. f .. '.HTML">' .. f .. '</a></p>'
	    end
	end

	-- Figure out this pages trail links.
	metadata.trail = ''
	for i, b in ipairs(bits) do
	    if i < #bits then
		metadata.trail = metadata.trail .. '<a href="' .. linkFrom(path, table.concat(bits, '/', 1, i)) .. whichPage(b) .. '">' .. b .. '</a> &nbsp; '
		linkFrom(path, table.concat(bits, '/', 1, i))
	    else
		metadata.trail = metadata.trail ..  b .. ' &nbsp; '
	    end
	end
--	if '' == metadata.trail then metadata.trail = '<a href="' .. string.rep('../', ln) .. '/' .. whichPage('') .. '">home</a> &nbsp; ' end

	-- Figure out this pages footer links.
	if nil ~= metadata.pagehistory then metadata.history = '<p>Page&nbsp;<a href="' .. metadata.pagehistory .. '">history</a></p>' end
	if nil ~= metadata.sourcecode	then metadata.footer = '<a href="' .. metadata.sourcecode	.. '">source code</a> &nbsp; &nbsp; ' .. metadata.footer    end
	if nil ~= metadata.feedatom		then metadata.footer = '<a href="' .. metadata.feedatom		..   '">atom feed</a> &nbsp; &nbsp; ' .. metadata.footer    end
	if metadata.footer ~= globalData.footer then metadata.footer = 'Web site ' .. metadata.footer end
	metadata.footer = '<p>' .. metadata.footer .. '</p>'

	-- Apply the template to the body.
	metadata.body = lcmark.apply_template(bod, metadata)

	-- Put it all in the template.
	local tm = ''
	if nil ~= file.template then
	    local h = io.open(file.template, 'r')
	    if nil ~= h then
		tm = tm .. h:read('*a')
		h:close()
	    else
		print('oops! No such file ' .. file.template)
	    end

-- TODO - Um not sure why this is here AND at the top of the loop.  Here makes more sense.
	    local template, err = lcmark.compile_template(tm)
	    if nil == template then print('oops! ' .. err) else
		result = lcmark.apply_template(template, metadata)
	    end
	else
	    result = body
	end

	-- Write the file.
	if '' ~= result then
	    local base = name .. '.HTML'
	    print('From ' .. name .. '.md -> ' .. base)
	    local a, e = io.open(base, 'w')
	    if nil == a then print('Could not open ' .. base .. ' - ' .. e) else
		a:write(result)
		a:close()
	    end
	end

    else
	print('')
    end
end