#include "LinkStep.h"

#include <string>
#include <fstream>

#include "sys.h"
#include "logger.h"
#include "globals.h"
#include "BXParser.h"

bool LinkStep::checkHasChanged(const std::string &outDir) {
	std::string targetPath = toolchain::targetFilePath(type_, path_, outDir);
	if (!sys::fileExists(targetPath)) {
		return true;
	}

	std::string confPath = this->confPath(outDir);
	if (!sys::fileExists(confPath)) {
		return true;
	}

	BXVariables cachedVariables;
	try {
		bufio::IFStream f(confPath);
		BXParser parser(f);
		parser.parse(cachedVariables);
	} catch (BXParseError &err) {
		logger::log(confPath + ": " + err.what());
		return true;
	}

	auto commandIt = cachedVariables.find("command");
	if (commandIt == cachedVariables.end()) {
		logger::log(confPath + ": Missing 'command' field");
		return true;
	}

	if (linkCommand(outDir) != commandIt->second) {
		return true;
	}

	return false;
}

void LinkStep::doBuild(const std::string &outDir) {
	std::vector<std::string> command = linkCommand(outDir);
	std::string dirPath = sys::dirname(outDir + '/' + path_);

	BXVariables newCachedVars = {
		{ "command", command},
	};

	bufio::OFStream f(confPath(outDir));
	BXWriter writer(f);
	writer.write(newCachedVars);

	sys::mkdirp(dirPath);
	sys::ProcConf conf;
	conf.print = true;
	conf.prefix = "(LD)";
	sys::execute(command, conf);
}

toolchain::FileType LinkStep::doGetLinkType() {
	for (auto &child: children()) {
		if (child->linkType() == toolchain::FileType::CXX) {
			return toolchain::FileType::CXX;
		}
	}

	return toolchain::FileType::C;
}

std::vector<std::string> &LinkStep::linkCommand(const std::string &outDir) {
	if (hasLinkCommand_) {
		return linkCommand_;
	}

	std::vector<std::string> objs;
	for (auto &dep: deps_) {
		for (auto &obj: dep->publicObjects(outDir)) {
			objs.push_back(obj);
		}
	}

	// TODO: Don't use FileType::CXX hard-coded here
	linkCommand_ = toolchain::getLinkCommand(
			publicLDFlags(outDir), publicLDLibs(outDir),
			linkType(), type_, objs, path_, outDir);
	hasLinkCommand_ = true;
	return linkCommand_;
}