#!/usr/bin/env lua

local candran = require("candran")
local parse = require("candran.can-parser.parser").parse
local pp = require("candran.can-parser.pp")
local util = require("candran.util")
local argparse = require("argparse")

-- Parse args --

local parser = argparse()
	:name "canc"
	:description("Candran "..candran.VERSION.." compiler by Reuh.")
	:epilog "For more info, see https://github.com/Reuh/candran"

parser:argument("filename", "Candran files to compile. Use - to read from standard input; the output file will then be named stdin.lua by default.")
	:args "+"

parser:group("Output options",
	parser:option("-d --destination")
		:description "Where compiled files should be written"
		:argname "directory",

	parser:option("-o --output")
		:description "Output filename. (default: same name as the input file with a .lua extension)"
		:argname "filename",

	parser:flag("-p --print")
		:description "Write to the standard output instead of creating files",

	parser:flag("--preprocess")
		:description "Only run the preprocessor",

	parser:flag("--compile")
		:description "Only run the compiler",

	parser:flag("--parse")
		:description "Only parse the file and prints syntax errors to stdout",

	parser:flag("--ast")
		:description"(for debugging purposes) Only parse the files and dump the AST to stdout"
)

util.cli.addCandranOptions(parser)

local args = parser:parse()

-- Compile --

for _, file in ipairs(args.filename) do
	-- Read
	local dest, input
	if file == "-" then
		dest = args.output or "stdin.lua"

		input = io.read("*a")

		args.chunkname = "stdin"
	else
		dest = args.output or (file:gsub("%.can$", "")..".lua")

		local inputFile, err = io.open(file, "r")
		if not inputFile then
			io.stderr:write("canc: cannot open "..file..": "..err.."\n")
			os.exit(1)
		end
		input = inputFile:read("*a")
		inputFile:close()

		args.chunkname = file
	end

	-- Parse-only situations
	if args.parse or args.ast then
		local ast, err = parse(input, args.chunkname)
		if not ast then
			io.stderr:write("canc: "..err.."\n")
			os.exit(1)
		end
		if args.ast then
			pp.dump(ast)
		end
		return
	end

	-- Compile and output
	local options = util.cli.makeCandranOptions(args)

	if args.destination then
		dest = args.destination .. "/" .. dest
	end

	if not args.print then
		print("Compiling "..args.chunkname.." in "..dest)
	end

	local out = input
	if args.preprocess then
		local r, err = candran.preprocess(out, options)
		if not r then
			io.stderr:write("canc: "..err.."\n")
			os.exit(1)
		end
		out = r
	end
	if args.compile then
		local r, err = candran.compile(out, options)
		if not r then
			io.stderr:write("canc: "..err.."\n")
			os.exit(1)
		end
		out = r
	end
	if args.compile == nil and args.preprocess == nil then
		local r, err = candran.make(input, options)
		if not r then
			io.stderr:write("canc: "..err.."\n")
			os.exit(1)
		end
		out = r
	end

	if args.print then
		print(out)
	else
		local outFile, err = io.open(dest, "w")
		if not outFile then
			os.execute("mkdir -p "..dest:gsub("[^/]+%.lua$", ""))
			outFile, err = io.open(dest, "w")
			if not outFile then
				io.stderr:write("canc: cannot open "..dest..": "..err)
				os.exit(1)
			end
		end
		outFile:write(out)
		outFile:close()
	end
end