#include "Version.hpp"

#include <boost/algorithm/string/predicate.hpp>
#include <boost/algorithm/string/trim.hpp>
#include <boost/nowide/fstream.hpp>

#include "../../libslic3r/libslic3r.h"
#include "../../libslic3r/Config.hpp"

namespace Slic3r { 
namespace GUI {
namespace Config {

static boost::optional<Semver> s_current_slic3r_semver = Semver::parse(SLIC3R_VERSION);

bool Version::is_current_slic3r_supported() const
{
	return this->is_slic3r_supported(*s_current_slic3r_semver);
}

inline char* left_trim(char *c)
{
	for (; *c == ' ' || *c == '\t'; ++ c);
	return c;
}

inline char* right_trim(char *start)
{
	char *end = start + strlen(start) - 1;
	for (; end >= start && (*end == ' ' || *end == '\t'); -- end);
	*(++ end) = 0;
	return end;
}

inline std::string unquote_value(char *value, char *end, const std::string &path, int idx_line)
{
	std::string svalue;
	if (value == end) {
		// Empty string is a valid string.
	} else if (*value == '"') {
		if (++ value < -- end || *end != '"')
			throw file_parser_error("String not enquoted correctly", path, idx_line);
		*end = 0;
		if (! unescape_string_cstyle(value, svalue))
			throw file_parser_error("Invalid escape sequence inside a quoted string", path, idx_line);
	}
	return svalue;
}

inline std::string unquote_version_comment(char *value, char *end, const std::string &path, int idx_line)
{
	std::string svalue;
	if (value == end) {
		// Empty string is a valid string.
	} else if (*value == '"') {
		if (++ value < -- end || *end != '"')
			throw file_parser_error("Version comment not enquoted correctly", path, idx_line);
		*end = 0;
		if (! unescape_string_cstyle(value, svalue))
			throw file_parser_error("Invalid escape sequence inside a quoted version comment", path, idx_line);
	}
	return svalue;
}

size_t Index::load(const std::string &path)
{
	m_configs.clear();

    boost::nowide::ifstream ifs(path);
    std::string line;
    size_t idx_line = 0;
    Version ver;
    while (std::getline(ifs, line)) {
    	++ idx_line;
    	// Skip the initial white spaces.
    	char *key = left_trim(const_cast<char*>(line.data()));
		// Right trim the line.
		char *end = right_trim(key);
		// Keyword may only contain alphanumeric characters. Semantic version may in addition contain "+.-".
    	char *key_end = key;
    	bool  maybe_semver = false;
    	for (;; ++ key) {
    		if (strchr("+.-", *key) != nullptr)
    			maybe_semver = true;
    		else if (! std::isalnum(*key))
    			break;
    	}
    	if (*key != 0 && *key != ' ' && *key != '\t' && *key != '=')
    		throw file_parser_error("Invalid keyword or semantic version", path, idx_line);
    	*key_end = 0;
    	boost::optional<Semver> semver;
    	if (maybe_semver)
    		semver = Semver::parse(key);
    	char *value = left_trim(key_end);
    	if (*value == '=') {
    		if (semver)
    			throw file_parser_error("Key cannot be a semantic version", path, idx_line);
    		// Verify validity of the key / value pair.
			std::string svalue = unquote_value(left_trim(++ value), end, path, idx_line);
    		if (key == "min_sic3r_version" || key == "max_slic3r_version") {
    			if (! svalue.empty())
		    		semver = Semver::parse(key);
		    	if (! semver)
		    		throw file_parser_error(std::string(key) + " must referece a valid semantic version", path, idx_line);
    			if (key == "min_sic3r_version")
    				ver.min_slic3r_version = *semver;
    			else
    				ver.max_slic3r_version = *semver;
    		} else {
    			// Ignore unknown keys, as there may come new keys in the future.
    		}
    	}
		if (! semver)
			throw file_parser_error("Invalid semantic version", path, idx_line);
		ver.config_version = *semver;
		ver.comment = (end <= key_end) ? "" : unquote_version_comment(value, end, path, idx_line);
		m_configs.emplace_back(ver);
    }

    return m_configs.size();
}

Index::const_iterator Index::recommended() const
{
	int idx = -1;
	const_iterator highest = m_configs.end();
	for (const_iterator it = this->begin(); it != this->end(); ++ it)
		if (it->is_current_slic3r_supported() &&
			(highest == this->end() || highest->max_slic3r_version < it->max_slic3r_version))
			highest = it;
	return highest;
}

} // namespace Config
} // namespace GUI
} // namespace Slic3r