/*
 * Copyright (C) 2016 Charybdis Development Team
 * Copyright (C) 2016 Jason Volk <jason@zemos.net>
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice is present in all copies.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <ircd/m.h>

ircd::m::session::session(const host_port &host_port)
:client{host_port}
{
}

ircd::json::object
ircd::m::session::operator()(parse::buffer &pb,
                             request &r)
{
	parse::capstan pc
	{
		pb, read_closure(*this)
	};

	http::request
	{
		host(remote_addr(*this)),
		r.method,
		r.path,
		r.query,
		std::string(r),
		write_closure(*this),
		{
			{ "Content-Type"s, "application/json"s }
		}
	};

	http::code status;
	json::object object;
	http::response
	{
		pc,
		nullptr,
		[&pc, &status, &object](const http::response::head &head)
		{
			status = http::status(head.status);
			object = http::response::content{pc, head};
		}
	};

	if(status < 200 || status >= 300)
		throw m::error(status, object);

	return object;
}

///////////////////////////////////////////////////////////////////////////////
//
// m/id.h
//

ircd::m::id::id(const string_view &id)
:string_view{id}
,sigil{m::sigil(id)}
{
}

ircd::m::id::id(const enum sigil &sigil,
                const string_view &id)
:string_view{id}
,sigil{sigil}
{
	if(!valid())
		throw INVALID_MXID("Not a valid '%s' mxid", reflect(sigil));
}

ircd::m::id::id(const enum sigil &sigil,
                char *const &buf,
                const size_t &max,
                const string_view &id)
:string_view{buf}
,sigil{sigil}
{
	strlcpy(buf, id, max);
}

ircd::m::id::id(const enum sigil &sigil,
                char *const &buf,
                const size_t &max,
                const string_view &name,
                const string_view &host)
:string_view{[&]() -> string_view
{
	if(!max)
		return {};

	size_t len(0);
	if(!startswith(name, sigil))
		buf[len++] = char(sigil);

	const auto has_sep
	{
		std::count(std::begin(name), std::end(name), ':')
	};

	if(!has_sep && host.empty())
	{
		len += strlcpy(buf + len, name, max - len);
	}
	else if(!has_sep && !host.empty())
	{
		len += fmt::snprintf(buf + len, max - len, "%s:%s",
		                     name,
		                     host);
	}
	else if(has_sep == 1 && !host.empty() && !split(name, ':').second.empty())
	{
		len += strlcpy(buf + len, name, max - len);
	}
	else if(has_sep && !host.empty())
	{
		throw INVALID_MXID("Not a valid '%s' mxid", reflect(sigil));
	}

	return { buf, len };
}()}
,sigil{sigil}
{
}

ircd::m::id::id(const enum sigil &sigil,
                char *const &buf,
                const size_t &max,
                const generate_t &,
                const string_view &host)
:string_view{[&]
{
	char name[64]; switch(sigil)
	{
		case sigil::USER:
			generate_random_prefixed(sigil::USER, "guest", name, sizeof(name));
			break;

		case sigil::ALIAS:
			generate_random_prefixed(sigil::ALIAS, "", name, sizeof(name));
			break;

		default:
			generate_random_timebased(sigil, name, sizeof(name));
			break;
	};

	const size_t len
	{
		fmt::snprintf(buf, max, "%s:%s",
		              name,
		              host)
	};

	return string_view { buf, len };
}()}
,sigil{sigil}
{
}

bool
ircd::m::id::valid()
const
{
	const auto parts(split(*this, ':'));
	const auto &local(parts.first);
	const auto &host(parts.second);

	// this valid() requires a full canonical mxid with a host
	if(host.empty())
		return false;

	// local requires a sigil plus at least one character
	if(local.size() < 2)
		return false;

	// local requires the correct sigil type
	if(!startswith(local, sigil))
		return false;

	return true;
}

bool
ircd::m::id::valid_local()
const
{
	const auto parts(split(*this, ':'));
	const auto &local(parts.first);

	// local requires a sigil plus at least one character
	if(local.size() < 2)
		return false;

	// local requires the correct sigil type
	if(!startswith(local, sigil))
		return false;

	return true;
}

ircd::string_view
ircd::m::id::generate_random_prefixed(const enum sigil &sigil,
                                      const string_view &prefix,
                                      char *const &buf,
                                      const size_t &max)
{
	const uint32_t num(rand::integer());
	const size_t len(fmt::snprintf(buf, max, "%c%s%u", char(sigil), prefix, num));
	return { buf, len };
}

ircd::string_view
ircd::m::id::generate_random_timebased(const enum sigil &sigil,
                                       char *const &buf,
                                       const size_t &max)
{
	const auto utime(microtime());
	const size_t len(snprintf(buf, max, "%c%zd%06d", char(sigil), utime.first, utime.second));
	return { buf, len };
}

enum ircd::m::id::sigil
ircd::m::sigil(const string_view &s)
try
{
	return sigil(s.at(0));
}
catch(const std::out_of_range &e)
{
	throw BAD_SIGIL("sigil undefined");
}

enum ircd::m::id::sigil
ircd::m::sigil(const char &c)
{
	switch(c)
	{
		case '$':  return id::EVENT;
		case '@':  return id::USER;
		case '#':  return id::ALIAS;
		case '!':  return id::ROOM;
	}

	throw BAD_SIGIL("'%c' is not a valid sigil", c);
}

const char *
ircd::m::reflect(const enum id::sigil &c)
{
	switch(c)
	{
		case id::EVENT:   return "EVENT";
		case id::USER:    return "USER";
		case id::ALIAS:   return "ALIAS";
		case id::ROOM:    return "ROOM";
	}

	return "?????";
}

bool
ircd::m::valid_sigil(const string_view &s)
try
{
	return valid_sigil(s.at(0));
}
catch(const std::out_of_range &e)
{
	return false;
}

bool
ircd::m::valid_sigil(const char &c)
{
	switch(c)
	{
		case id::EVENT:
		case id::USER:
		case id::ALIAS:
		case id::ROOM:
			return true;
	}

	return false;
}