#!/usr/bin/env lua

local argparse = require "argparse"
local lfs = require "lfs"

local parser = argparse()

parser:flag("-l --lint", "Perform a lint on the file instead of compiling")
parser:flag("-v --version", "Print version")
parser:flag("-w --watch", "Watch file/directory for updates")
parser:option("--transform", "Transform syntax tree with module")
parser:mutex(
	parser:option("-t --output-to", "Specify where to place compiled files"),
	parser:option("-o", "Write output to file"),
	parser:flag("-p", "Write output to standard output"),
	parser:flag("-T", "Write parse tree instead of code (to stdout)"),
	parser:flag("-b", "Write parse and compile time instead of code(to stdout)"),
	parser:flag("-X", "Write line rewrite map instead of code (to stdout)")
)
parser:flag("-",
	"Read from standard in, print to standard out (Must be only argument)")

local read_stdin = arg[1] == "--" -- luacheck: ignore 113

if not read_stdin then
	parser:argument("file/directory"):args("+")
end

local opts = parser:parse()

if opts.version then
	local v = require "moonscript.version"
	v.print_version()
	os.exit()
end

function log_msg(...)
	if not opts.p then
		io.stderr:write(table.concat({...}, " ") .. "\n")
	end
end

local moonc = require("moonscript.cmd.moonc")
local util = require "moonscript.util"
local normalize_dir = moonc.normalize_dir
local compile_and_write = moonc.compile_and_write
local path_to_target = moonc.path_to_target

local function scan_directory(root, collected)
	root = normalize_dir(root)
	collected = collected or {}

	for fname in lfs.dir(root) do
		if not fname:match("^%.") then
			local full_path = root..fname

			if lfs.attributes(full_path, "mode") == "directory" then
				scan_directory(full_path, collected)
			elseif fname:match("%.moon$") then
				table.insert(collected, full_path)
			end
		end
	end

	return collected
end

local function remove_dups(tbl, key_fn)
	local hash = {}
	local final = {}

	for _, v in ipairs(tbl) do
		local dup_key = key_fn and key_fn(v) or v
		if not hash[dup_key] then
			table.insert(final, v)
			hash[dup_key] = true
		end
	end

	return final
end

-- creates tuples of input and target
local function get_files(fname, files)
	files = files or {}

	if lfs.attributes(fname, "mode") == "directory" then
		for _, sub_fname in ipairs(scan_directory(fname)) do
			table.insert(files, {
				sub_fname,
				path_to_target(sub_fname, opts.output_to, fname)
			})
		end
	else
		table.insert(files, {
			fname,
			path_to_target(fname, opts.output_to)
		})
	end

	return files
end

if read_stdin then
	local parse = require "moonscript.parse"
	local compile = require "moonscript.compile"

	local text = io.stdin:read("*a")
	local tree, err = parse.string(text)

	if not tree then error(err) end
	local code, err, pos = compile.tree(tree)

	if not code then
		error(compile.format_error(err, pos, text))
	end

	print(code)
	os.exit()
end

local inputs = opts["file/directory"]

local files = {}
for _, input in ipairs(inputs) do
	get_files(input, files)
end

files = remove_dups(files, function(f)
	return f[2]
end)

-- returns an iterator that returns files that have been updated
local function create_watcher(files)
	local watchers = require("moonscript.cmd.watchers")

	if watchers.InotifyWacher:available() then
		return watchers.InotifyWacher(files):each_update()
	end

	return watchers.SleepWatcher(files):each_update()
end

if opts.watch then
	-- build function to check for lint or compile in watch
	local handle_file
	if opts.lint then
		local lint = require "moonscript.cmd.lint"
		handle_file = lint.lint_file
	else
		handle_file = compile_and_write
	end

	local watcher = create_watcher(files)
	-- catches interrupt error for ctl-c
	local protected = function()
		local status, file = true, watcher()
		if status then
			return file
		elseif file ~= "interrupted!" then
			error(file)
		end
	end

	for fname in protected do
		local target = path_to_target(fname, opts.t)

		if opts.o then
			target = opts.o
		end

		local success, err = handle_file(fname, target)
		if opts.lint then
			if success then
				io.stderr:write(success .. "\n\n")
			elseif err then
				io.stderr:write(fname .. "\n" .. err .. "\n\n")
			end
		elseif not success then
			io.stderr:write(table.concat({
				"",
				"Error: " .. fname,
				err,
				"\n",
			}, "\n"))
		elseif success == "build" then
			log_msg("Built", fname, "->", target)
		end
	end

	io.stderr:write("\nQuitting...\n")
elseif opts.lint then
	local has_linted_with_error;
	local lint = require "moonscript.cmd.lint"
	for _, tuple in pairs(files) do
		local fname = tuple[1]
		local res, err = lint.lint_file(fname)
		if res then
			has_linted_with_error = true
			io.stderr:write(res .. "\n\n")
		elseif err then
			has_linted_with_error = true
			io.stderr:write(fname .. "\n" .. err.. "\n\n")
		end
	end
	if has_linted_with_error then
		os.exit(1)
	end
else
	for _, tuple in ipairs(files) do
		local fname, target = util.unpack(tuple)
		if opts.o then
			target = opts.o
		end

		local success, err = compile_and_write(fname, target, {
			print = opts.p,
			fname = fname,
			benchmark = opts.b,
			show_posmap = opts.X,
			show_parse_tree = opts.T,
			transform_module = opts.transform
		})

		if not success then
			io.stderr:write(fname .. "\t" .. err .. "\n")
			os.exit(1)
		end
	end
end