#include <nlohmann/json.hpp>
using json = nlohmann::json;


// https://github.com/nlohmann/json/issues/760
namespace nlohmann {
	template <typename T>
	struct adl_serializer<std::optional<T>> {
		static void to_json(json & j, const std::optional<T> & opt) {
			if(opt == std::nullopt) {
				j = nullptr;
			} else {
				j = *opt;
			}
		}

		static void from_json(const json & j, std::optional<T> & opt) {
			if(j.is_null()) {
				opt = std::nullopt;
			} else {
				opt = j.get<T>();
			}
		}
	};
}


struct poster {
	unsigned projectId;
	std::string handle;
	std::string displayName;
	std::string avatarURL;
};
NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE(poster, projectId, handle, displayName, avatarURL)


// cohost.org/exerian has no DM
// cohost.org/bobbi has no DM
static const std::map<unsigned, const char *> uid_maps = {
    {64525, "//101010.pl/@nabijaczleweli"},
    {817, "//infosec.exchange/@atax1a"},
    {31790, "//azabani.com"},
    {10798, "//www.iximeow.net"},
};
static unsigned excluded_uids[] = {
#include "excluded.h"
};


void htmlencode(std::string & of, bool quotes = false) {
	for(std::size_t i{}; (i = of.find('&', i)) != std::string::npos;) {
		of.replace(i, 1, "&amp;");
		++i;
	}
	for(std::size_t i; (i = of.find('<')) != std::string::npos;)
		of.replace(i, 1, "&lt;");
	if(quotes) {
		for(std::size_t i; (i = of.find('"')) != std::string::npos;)
			of.replace(i, 1, "&quot;");
	}
}


static regex_t autolink_regex = [] {
	regex_t ret;
	//                                 2                    4
	if(auto e = regcomp(&ret, "(^|[	 ])(http(s?)://[^	 ]*)(([.,:;!)] )|([.,:;!)]*([	 ]|$))|$)", REG_EXTENDED | REG_NEWLINE)) {
		char err[1024];
		regerror(e, &ret, err, 1024);
		fputs(err, stderr);
		fputc('\n', stderr);
		abort();
	}
	assert(ret.re_nsub >= 4);
	return ret;
}();
static regex_t videoify_regex = [] {
	regex_t ret;
	if(auto e = regcomp(&ret, "^http(s?)://[^	 ]*.(mp4|webm)$", REG_EXTENDED | REG_NEWLINE | REG_ICASE)) {
		char err[1024];
		regerror(e, &ret, err, 1024);
		fputs(err, stderr);
		fputc('\n', stderr);
		abort();
	}
	return ret;
}();


// https://cohost.org/staff/post/1477549-cohost-patch-notes-v
// date -d '2023-05-10T15:00 EDT' -u +%s
static constexpr time_t fixlines_after = 1683745200;
void markdownise(std::string & m, time_t m_at, int memfd) {
	regmatch_t matches[10];
	for(;;) {
		matches->rm_so = 0;
		matches->rm_eo = m.size();
		if(regexec(&videoify_regex, m.data(), 10, matches, REG_STARTEND))
			break;

		// <video controls>
		std::string_view url{m.data() + matches->rm_so, size_t(matches->rm_eo - matches->rm_so)};
		char * vid;
		assert(asprintf(&vid,
		                "<video controls>"
		                "	<source src=\"%1$.*2$s\">"
		                "	<a href=\"%1$.*2$s\">%1$.*2$s</a>"
		                "</video>",
		                url.data(), (int)url.size()) != -1);
		m.replace(matches->rm_so, matches->rm_eo - matches->rm_so, vid);
		free(vid);
	}
	for(;;) {
		matches->rm_so = 0;
		matches->rm_eo = m.size();
		if(regexec(&autolink_regex, m.data(), 10, matches, REG_STARTEND))
			break;
		// TODO: doesn't respect ```; only affects post-1397531 in my dataset so leaving
		while(m[matches[4].rm_so - 1] == '.' || m[matches[4].rm_so - 1] == ',' || m[matches[4].rm_so - 1] == ':' || m[matches[4].rm_so - 1] == ';' ||
		      m[matches[4].rm_so - 1] == '!' || m[matches[4].rm_so - 1] == ')')
			--matches[4].rm_so;
		m.insert(std::begin(m) + matches[4].rm_so, '>');
		m.insert(std::begin(m) + matches[2].rm_so, '<');
	}


	fflush(stdout);
	// printf("	<p>\n%s\n	</p>\n", m.data());
	lseek(memfd, 0, SEEK_SET);
	assert(write(memfd, m.data(), m.size()) == m.size());
	assert(!ftruncate(memfd, m.size()));
	lseek(memfd, 0, SEEK_SET);
	if(!vfork()) {
		dup2(memfd, 0);
		_exit(execlp("cmark", "cmark", "--unsafe", m_at > fixlines_after ? "--hardbreaks" : nullptr, (char *)nullptr));
	}
	wait(nullptr);
}


// "2023-02-09T17:29:38.142Z",
time_t parse_iso_like(std::string t) {
	t.erase(t.find('.'));
	t.push_back('Z');
	struct tm tm {};
	strptime(t.data(), "%Y-%m-%dT%H:%M:%S%z", &tm);
	return mktime(&tm);
}