#include "CodegenUtils.hpp"

#include <Macros.hpp>
#include <ScopeGuard.hpp>
#include <Utils.hpp>

#include <cstdio>
#include <cstdlib>

bool Utils::WriteOutputFile(const CodegenOutput& output, const char* path) {
	auto outputFile = Utils::OpenCstdioFile(path, Utils::WriteTruncate);
	if (!outputFile) {
		printf("[ERROR] unable to open output file %s\n", path);
		return false;
	}
	DEFER { fclose(outputFile); };

	DEBUG_PRINTF("Writing output %s\n", path);
	output.Write(outputFile);

	return true;
}

std::string Utils::MakeFullName(std::string_view name, DeclNamespace* ns) {
	size_t length = 0;
	std::vector<std::string_view> components;
	if (!name.empty()) {
		components.push_back(name);
		length += name.length();
	}

	DeclNamespace* currentNamespace = ns;
	while (currentNamespace) {
		components.push_back(currentNamespace->name);
		length += currentNamespace->name.size() + /*::*/ 2;
		currentNamespace = currentNamespace->container;
	}

	std::string fullname;
	fullname.reserve(length);
	for (auto it = components.rbegin(); it != components.rend(); ++it) {
		fullname += *it;
		fullname += "::";
	}
	// Get rid of the last "::"
	fullname.pop_back();
	fullname.pop_back();

	return fullname;
}

// NOTE: assuming we are only dealing with ASCII characters
static bool IsLowerCase(char c) {
	return c >= 'a' && c <= 'z';
}
static bool IsUpperCase(char c) {
	return c >= 'A' && c <= 'Z';
}
static bool IsAlphabetic(char c) {
	return IsLowerCase(c) || IsUpperCase(c);
}
static char MakeUpperCase(char c) {
	if (IsAlphabetic(c)) {
		return IsUpperCase(c)
			? c
			: ('A' + (c - 'a'));
	}
	return c;
}

std::vector<std::string_view> Utils::SplitIdentifier(std::string_view name) {
	// TODO handle SCREAMING_CASE

	size_t chunkStart = 0;
	size_t chunkEnd = 0;
	std::vector<std::string_view> result;
	auto PushChunk = [&]() { result.push_back(std::string_view(name.begin() + chunkStart, name.begin() + chunkEnd)); };
	while (chunkEnd < name.size()) {
		char c = name[chunkEnd];
		if (IsUpperCase(c)) {
			// Start of next chunk, using camelCase or PascalCase
			PushChunk();
			chunkStart = chunkEnd;
			chunkEnd = chunkStart + 1;
			continue;
		} else if (c == '_') {
			// End of this chunk, using snake_case
			PushChunk();
			chunkStart = chunkEnd + 1;
			chunkEnd = chunkStart + 1;
			continue;
		} else if (c == '-') {
			// End of this chunk, using kebab-case
			PushChunk();
			chunkStart = chunkEnd + 1;
			chunkEnd = chunkStart + 1;
			continue;
		}
		++chunkEnd;
	}

	if ((chunkEnd - chunkStart) >= 1) {
		PushChunk();
	}

	return result;
}

std::string Utils::MakePascalCase(std::string_view name) {
	std::string result;
	for (auto part : SplitIdentifier(name)) {
		result += MakeUpperCase(part[0]);
		result += part.substr(1);
	}
	return result;
}

void Utils::ProduceGeneratedHeader(const char* headerFilename, CodegenOutput& header, const char* sourceFilename, CodegenOutput& source) {
	CodegenOutputThing headerOut;
	headerOut.text += &R"""(
// This file is generated. Any changes will be overidden when building.
#pragma once
#include <MetadataBase.hpp>
#include <cstddef>
#include <cstdint>
)"""[1];

	CodegenOutputThing sourceOut;
	APPEND_LIT_LN(sourceOut.text, "// This file is generated. Any changes will be overidden when building.");
	APPEND_FMT_LN(sourceOut.text, "#include \"%s\"", headerFilename);
	sourceOut.text += &R"""(
#include <MetadataDetails.hpp>
#include <frozen/string.h>
#include <frozen/unordered_map.h>
using namespace std::literals;
)"""[1];

	header.AddOutputThing(std::move(headerOut));
	source.AddOutputThing(std::move(sourceOut));
}

void Utils::ProduceClassTypeInfo(CodegenOutput& source, std::string_view className, const DeclNamespace* ns) {
	CodegenOutputThing thing;

	source.AddOutputThing(std::move(thing));
}