#include "protocol.hfa"

#define _GNU_SOURCE
extern "C" {
	#include <fcntl.h>
}

#define xstr(s) str(s)
#define str(s) #s

#include <fstream.hfa>
#include <iofwd.hfa>
#include <io/types.hfa>
#include <mutex_stmt.hfa>

#include <assert.h>
// #include <stdio.h> // Don't use stdio.h, too slow to compile
extern "C" {
      int snprintf ( char * s, size_t n, const char * format, ... );
	ssize_t sendfile(int out_fd, int in_fd, off_t *offset, size_t count);
	// #include <linux/io_uring.h>
}
#include <string.h>
#include <errno.h>

#include "options.hfa"
#include "worker.hfa"

#define PLAINTEXT_1WRITE
#define PLAINTEXT_MEMCPY
#define PLAINTEXT_NOCOPY
// #define LINKED_IO
#define TRUE_SENDFILE

static inline __s32 wait_res( io_future_t & this ) {
	wait( this );
	if( this.result < 0 ) {{
		errno = -this.result;
		return -1;
	}}
	return this.result;
}

struct https_msg_str {
	char msg[512];
	size_t len;
};

const https_msg_str * volatile http_msgs[KNOWN_CODES] = { 0 };

_Static_assert( KNOWN_CODES == (sizeof(http_msgs ) / sizeof(http_msgs [0])));

const int http_codes[KNOWN_CODES] = {
	200,
	200,
	400,
	404,
	405,
	408,
	413,
	414,
};

_Static_assert( KNOWN_CODES == (sizeof(http_codes) / sizeof(http_codes[0])));

int code_val(HttpCode code) {
	return http_codes[code];
}

static inline int answer( int fd, const char * it, int len ) {
	while(len > 0) {
		// Call write
		int ret = cfa_send(fd, it, len, 0, CFA_IO_LAZY);
		if( ret < 0 ) {
			if( errno == ECONNRESET || errno == EPIPE || errno == EBADF ) {
				ret = close(fd);
				if( ret != 0 ) abort( "close in 'answer' error: (%d) %s\n", (int)errno, strerror(errno) );
				return -ECONNRESET;
			}

			abort( "'answer error' error: (%d) %s\n", (int)errno, strerror(errno) );
		}

		// update it/len
		it  += ret;
		len -= ret;
	}
	return 0;
}

// int answer_error( int fd, HttpCode code ) {
// 	/* paranoid */ assert( code < KNOWN_CODES && code != OK200 );
// 	int idx = (int)code;
// 	return answer( fd, http_msgs[idx]->msg, http_msgs[idx]->len );
// }

static int fill_header(char * it, size_t size) {
	memcpy(it, http_msgs[OK200]->msg, http_msgs[OK200]->len);
	it += http_msgs[OK200]->len;
	int len = http_msgs[OK200]->len;
	len += snprintf(it, 512 - len, "%d \n\n", size);
	return len;
}

static int answer_header( int fd, size_t size ) {
	char buffer[512];
	int len = fill_header(buffer, size);
	return answer( fd, buffer, len );
}

// #if defined(PLAINTEXT_NOCOPY)
// int answer_plaintext( int fd ) {
// 	return answer(fd, http_msgs[OK200_PlainText]->msg, http_msgs[OK200_PlainText]->len); // +1 cause snprintf doesn't count nullterminator
// }
// #elif defined(PLAINTEXT_MEMCPY)
// #define TEXTSIZE 15
// int answer_plaintext( int fd ) {
// 	char text[] = "Hello, World!\n\n";
// 	char ts[] = xstr(TEXTSIZE) " \n\n";
// 	_Static_assert(sizeof(text) - 1 == TEXTSIZE);
// 	char buffer[512 + TEXTSIZE];
// 	char * it = buffer;
// 	memcpy(it, http_msgs[OK200]->msg, http_msgs[OK200]->len);
// 	it += http_msgs[OK200]->len;
// 	int len = http_msgs[OK200]->len;
// 	memcpy(it, ts, sizeof(ts) - 1);
// 	it += sizeof(ts) - 1;
// 	len += sizeof(ts) - 1;
// 	memcpy(it, text, TEXTSIZE);
// 	return answer(fd, buffer, len + TEXTSIZE);
// }
// #elif defined(PLAINTEXT_1WRITE)
// int answer_plaintext( int fd ) {
// 	char text[] = "Hello, World!\n\n";
// 	char buffer[512 + sizeof(text)];
// 	char * it = buffer;
// 	memcpy(it, http_msgs[OK200]->msg, http_msgs[OK200]->len);
// 	it += http_msgs[OK200]->len;
// 	int len = http_msgs[OK200]->len;
// 	int r = snprintf(it, 512 - len, "%d \n\n", sizeof(text));
// 	it += r;
// 	len += r;
// 	memcpy(it, text, sizeof(text));
// 	return answer(fd, buffer, len + sizeof(text));
// }
// #else
// int answer_plaintext( int fd ) {
// 	char text[] = "Hello, World!\n\n";
// 	int ret = answer_header(fd, sizeof(text));
// 	if( ret < 0 ) return ret;
// 	return answer(fd, text, sizeof(text));
// }
// #endif

// int answer_empty( int fd ) {
// 	return answer_header(fd, 0);
// }

static int sendfile( int pipe[2], int fd, int ans_fd, size_t count, sendfile_stats_t & stats ) {
	int zipf_idx = -1;
	STATS: for(i; zipf_cnts) {
		if(count <= zipf_sizes[i]) {
			zipf_idx = i;
			break STATS;
		}
	}
	if(zipf_idx < 0) mutex(serr) serr | "SENDFILE" | count | " greated than biggest zipf file";

	#if defined(TRUE_SENDFILE)
		off_t offset = 0;
		ssize_t ret;
		int flags = fcntl(fd, F_GETFL);
		if(flags < 0) abort("getfl in 'true sendfile' error: (%d) %s\n", (int)errno, strerror(errno) );
		ret = fcntl(fd, F_SETFL, flags | O_NONBLOCK);
		if(ret < 0) abort("setfl in 'true sendfile' error: (%d) %s\n", (int)errno, strerror(errno) );

		while(count) {
		 	ret = sendfile(fd, ans_fd, &offset, count);
			if( ret <= 0 ) {
				if( errno == EAGAIN || errno == EWOULDBLOCK ) {
					stats.eagain++;
					yield();
					continue;
				}
				if( errno == ECONNRESET || errno == EPIPE ) {
					ret = close(fd);
					if( ret != 0 ) abort( "close in 'true sendfile' error: (%d) %s\n", (int)errno, strerror(errno) );
					return -ECONNRESET;
				}
				abort( "sendfile error: %d (%d) %s\n", ret, (int)errno, strerror(errno) );
			}
			count -= ret;
			stats.splcin++;
			if(count > 0) stats.avgrd[zipf_idx].calls++;
			stats.avgrd[zipf_idx].bytes += ret;
		}

		ret = fcntl(fd, F_SETFL, flags & ~O_NONBLOCK);
		if(ret < 0) abort("resetfl in 'true sendfile' error: (%d) %s\n", (int)errno, strerror(errno) );
	#else
		#error not implemented
		// unsigned sflags = SPLICE_F_MOVE; // | SPLICE_F_MORE;
		// off_t offset = 0;
		// ssize_t ret;
		// SPLICE1: while(count > 0) {
		// 	stats.tries++;
		// 	// ret = cfa_splice(ans_fd, &offset, pipe[1], 0p, count, sflags, CFA_IO_LAZY);
		// 	ret = splice(ans_fd, &offset, pipe[1], 0p, count, sflags);
		// 	if( ret <= 0 ) {
		// 		if( errno == ECONNRESET || errno == EPIPE ) {
		// 			ret = close(fd);
		// 			if( ret != 0 ) abort( "close in 'sendfile splice in' error: (%d) %s\n", (int)errno, strerror(errno) );
		// 			return -ECONNRESET;
		// 		}
		// 		abort( "splice [0] error: %d (%d) %s\n", ret, (int)errno, strerror(errno) );
		// 	}
		// 	count -= ret;
		// 	stats.splcin++;
		// 	if(count > 0) stats.avgrd[zipf_idx].calls++;
		// 	stats.avgrd[zipf_idx].bytes += ret;

		// 	size_t in_pipe = ret;
		// 	SPLICE2: while(in_pipe > 0) {
		// 		ret = cfa_splice(pipe[0], 0p, fd, 0p, in_pipe, sflags, CFA_IO_LAZY);
		// 		// ret = splice(pipe[0], 0p, fd, 0p, in_pipe, sflags);
		// 		if( ret <= 0 ) {
		// 			if( errno == ECONNRESET || errno == EPIPE ) {
		// 				ret = close(fd);
		// 				if( ret != 0 ) abort( "close in 'sendfile splice out' error: (%d) %s\n", (int)errno, strerror(errno) );
		// 				return -ECONNRESET;
		// 			}
		// 			abort( "splice [1] error: %d (%d) %s\n", ret, (int)errno, strerror(errno) );
		// 		}
		// 		stats.splcot++;
		// 		in_pipe -= ret;
		// 	}

		// }
	#endif

	return count;
}

// enum FSM_STATE {
// 	Initial,
// 	Retry,
// 	Error,
// 	Done,
// };

// struct FSM_Result {
// 	FSM_STATE state;
// 	int error;
// };

// static inline void ?{}(FSM_Result & this) { this.state = Initial; this.error = 0; }
// static inline bool is_error(FSM_Result & this) { return Error == this.state; }
// static inline bool is_done(FSM_Result & this) { return Done == this.state; }

// static inline int error(FSM_Result & this, int error) {
// 	this.error = error;
// 	this.state = Error;
// 	return error;
// }

// static inline int done(FSM_Result & this) {
// 	this.state = Done;
// 	return 0;
// }

// static inline int retry(FSM_Result & this) {
// 	this.state = Retry;
// 	return 0;
// }

// static inline int need(FSM_Result & this) {
// 	switch(this.state) {
// 		case Initial:
// 		case Retry:
// 			return 1;
// 		case Error:
// 			if(this.error == 0) mutex(serr) serr | "State marked error but code is 0";
// 		case Done:
// 			return 0;
// 	}
// }

// // Generator that handles sending the header
// generator header_g {
// 	io_future_t f;
// 	const char * next;
// 	int fd; size_t len;
// 	FSM_Result res;
// };

// static inline void ?{}(header_g & this, int fd, const char * it, size_t len ) {
// 	this.next = it;
// 	this.fd = fd;
// 	this.len = len;
// }

// static inline void fill(header_g & this, struct io_uring_sqe * sqe) {
// 	zero_sqe(sqe);
// 	sqe->opcode = IORING_OP_SEND;
// 	sqe->user_data = (uintptr_t)&this.f;
// 	sqe->flags = IOSQE_IO_LINK;
// 	sqe->fd = this.fd;
// 	sqe->addr = (uintptr_t)this.next;
// 	sqe->len = this.len;
// }

// static inline int error(header_g & this, int error) {
// 	int ret = close(this.fd);
// 	if( ret != 0 ) {
// 		mutex(serr) serr | "Failed to close fd" | errno;
// 	}
// 	return error(this.res, error);
// }

// static inline int wait_and_process(header_g & this, sendfile_stats_t & stats) {
// 	wait(this.f);

// 	// Did something crazy happen?
// 	if(this.f.result > this.len) {
// 		mutex(serr) serr | "HEADER sent too much!";
// 		return error(this, -ERANGE);
// 	}

// 	// Something failed?
// 	if(this.f.result < 0) {
// 		int error = -this.f.result;
// 		if( error == ECONNRESET ) return error(this, -ECONNRESET);
// 		if( error == EPIPE ) return error(this, -EPIPE);
// 		if( error == ECANCELED ) {
// 			mutex(serr) serr | "HEADER was cancelled, WTF!";
// 			return error(this, -ECONNRESET);
// 		}
// 		if( error == EAGAIN || error == EWOULDBLOCK) {
// 			mutex(serr) serr | "HEADER got eagain, WTF!";
// 			return error(this, -ECONNRESET);
// 		}
// 	}

// 	// Done?
// 	if(this.f.result == this.len) {
// 		return done(this.res);
// 	}

// 	stats.header++;

// 	// It must be a Short read
// 	this.len  -= this.f.result;
// 	this.next += this.f.result;
// 	reset(this.f);
// 	return retry(this.res);
// }

// // Generator that handles splicing in a file
// struct splice_in_t {
// 	io_future_t f;
// 	int fd; int pipe; size_t len; off_t off;
// 	short zipf_idx;
// 	FSM_Result res;
// };

// static inline void ?{}(splice_in_t & this, int fd, int pipe, size_t len) {
// 	this.fd = fd;
// 	this.pipe = pipe;
// 	this.len = len;
// 	this.off = 0;
// 	this.zipf_idx = -1;
// 	STATS: for(i; zipf_cnts) {
// 		if(len <= zipf_sizes[i]) {
// 			this.zipf_idx = i;
// 			break STATS;
// 		}
// 	}
// 	if(this.zipf_idx < 0) mutex(serr) serr | "SPLICE IN" | len | " greated than biggest zipf file";
// }

// static inline void fill(splice_in_t & this, struct io_uring_sqe * sqe) {
// 	zero_sqe(sqe);
// 	sqe->opcode = IORING_OP_SPLICE;
// 	sqe->user_data = (uintptr_t)&this.f;
// 	sqe->flags = 0;
// 	sqe->splice_fd_in = this.fd;
// 	sqe->splice_off_in = this.off;
// 	sqe->fd = this.pipe;
// 	sqe->off = (__u64)-1;
// 	sqe->len = this.len;
// 	sqe->splice_flags = SPLICE_F_MOVE;
// }

// static inline int wait_and_process(splice_in_t & this, sendfile_stats_t & stats ) {
// 	wait(this.f);

// 	// Something failed?
// 	if(this.f.result < 0) {
// 		int error = -this.f.result;
// 		if( error == ECONNRESET ) return error(this.res, -ECONNRESET);
// 		if( error == EPIPE ) return error(this.res, -EPIPE);
// 		if( error == ECANCELED ) {
// 			mutex(serr) serr | "SPLICE IN was cancelled, WTF!";
// 			return error(this.res, -ECONNRESET);
// 		}
// 		if( error == EAGAIN || error == EWOULDBLOCK) {
// 			mutex(serr) serr | "SPLICE IN got eagain, WTF!";
// 			return error(this.res, -ECONNRESET);
// 		}
// 		mutex(serr) serr | "SPLICE IN got" | error | ", WTF!";
// 		return error(this.res, -ECONNRESET);
// 	}

// 	// Did something crazy happen?
// 	if(this.f.result > this.len) {
// 		mutex(serr) serr | "SPLICE IN spliced too much!";
// 		return error(this.res, -ERANGE);
// 	}

// 	// Done?
// 	if(this.f.result == this.len) {
// 		return done(this.res);
// 	}

// 	stats.splcin++;
// 	stats.avgrd[this.zipf_idx].calls++;
// 	stats.avgrd[this.zipf_idx].bytes += this.f.result;

// 	// It must be a Short read
// 	this.len -= this.f.result;
// 	this.off += this.f.result;
// 	reset(this.f);
// 	return retry(this.res);
// }

// generator splice_out_g {
// 	io_future_t f;
// 	int pipe; int fd; size_t len;
// 	FSM_Result res;
// };

// static inline void ?{}(splice_out_g & this, int pipe, int fd, size_t len) {
// 	this.pipe = pipe;
// 	this.fd = fd;
// 	this.len = len;
// }

// static inline void fill(splice_out_g & this, struct io_uring_sqe * sqe) {
// 	zero_sqe(sqe);
// 	sqe->opcode = IORING_OP_SPLICE;
// 	sqe->user_data = (uintptr_t)&this.f;
// 	sqe->flags = 0;
// 	sqe->splice_fd_in = this.pipe;
// 	sqe->splice_off_in = (__u64)-1;
// 	sqe->fd = this.fd;
// 	sqe->off = (__u64)-1;
// 	sqe->len = this.len;
// 	sqe->splice_flags = SPLICE_F_MOVE;
// }

// static inline int error(splice_out_g & this, int error) {
// 	int ret = close(this.fd);
// 	if( ret != 0 ) {
// 		mutex(serr) serr | "Failed to close fd" | errno;
// 	}
// 	return error(this.res, error);
// }

// static inline void wait_and_process(splice_out_g & this, sendfile_stats_t & stats ) {
// 	wait(this.f);

// 	// Something failed?
// 	if(this.f.result < 0) {
// 		int error = -this.f.result;
// 		if( error == ECONNRESET ) return error(this, -ECONNRESET);
// 		if( error == EPIPE ) return error(this, -EPIPE);
// 		if( error == ECANCELED ) {
// 			this.f.result = 0;
// 			goto SHORT_WRITE;
// 		}
// 		if( error == EAGAIN || error == EWOULDBLOCK) {
// 			mutex(serr) serr | "SPLICE OUT got eagain, WTF!";
// 			return error(this, -ECONNRESET);
// 		}
// 		mutex(serr) serr | "SPLICE OUT got" | error | ", WTF!";
// 		return error(this, -ECONNRESET);
// 	}

// 	// Did something crazy happen?
// 	if(this.f.result > this.len) {
// 		mutex(serr) serr | "SPLICE OUT spliced too much!" | this.f.result | ">" | this.len;
// 		return error(this.res, -ERANGE);
// 	}

// 	// Done?
// 	if(this.f.result == this.len) {
// 		return done(this.res);
// 	}

// SHORT_WRITE:
// 	stats.splcot++;

// 	// It must be a Short Write
// 	this.len -= this.f.result;
// 	reset(this.f);
// 	return retry(this.res);
// }

int answer_sendfile( int pipe[2], int fd, int ans_fd, size_t fsize, sendfile_stats_t & stats ) {
	stats.calls++;
	#if defined(LINKED_IO)
		// char buffer[512];
		// int len = fill_header(buffer, fsize);
		// header_g header = { fd, buffer, len };
		// splice_in_t splice_in = { ans_fd, pipe[1], fsize };
		// splice_out_g splice_out = { pipe[0], fd, fsize };

		// RETRY_LOOP: for() {
		// 	stats.tries++;
		// 	int have = need(header.res) + need(splice_in.res) + 1;
		// 	int idx = 0;
		// 	struct io_uring_sqe * sqes[3];
		// 	__u32 idxs[3];
		// 	struct io_context$ * ctx = cfa_io_allocate(sqes, idxs, have);

		// 	if(need(splice_in.res)) { fill(splice_in, sqes[idx++]); }
		// 	if(need(   header.res)) { fill(header   , sqes[idx++]); }
		// 	fill(splice_out, sqes[idx]);

		// 	// Submit everything
		// 	asm volatile("": : :"memory");
		// 	cfa_io_submit( ctx, idxs, have, false );

		// 	// wait for the results
		// 	// Always wait for splice-in to complete as
		// 	// we may need to kill the connection if it fails
		// 	// If it already completed, this is a no-op
		// 	wait_and_process(splice_in, stats);

		// 	if(is_error(splice_in.res)) {
		// 		if(splice_in.res.error == -EPIPE) return -ECONNRESET;
		// 		mutex(serr) serr | "SPLICE IN failed with" | splice_in.res.error;
		// 		int ret = close(fd);
		// 		if( ret != 0 ) abort( "close in 'answer sendfile' error: (%d) %s\n", (int)errno, strerror(errno) );
		// 	}

		// 	// Process the other 2
		// 	wait_and_process(header, stats);
		// 	wait_and_process(splice_out, stats);

		// 	if(is_done(splice_out.res)) {
		// 		break RETRY_LOOP;
		// 	}

		// 	// We need to wait for the completion if
		// 	// - both completed
		// 	// - the header failed
		// 	// -

		// 	if(  is_error(header.res)
		// 	  || is_error(splice_in.res)
		// 	  || is_error(splice_out.res)) {
		// 		return -ECONNRESET;
		// 	}
		// }

		// return len + fsize;
	#else
		int ret = answer_header(fd, fsize);
		if( ret < 0 ) { return ret; }
		return sendfile(pipe, fd, ans_fd, fsize, stats);
	#endif
}

[HttpCode code, bool closed, * const char file, size_t len] http_read(volatile int & fd, []char buffer, size_t len, io_future_t * f) {
	char * it = buffer;
	size_t count = len - 1;
	int rlen = 0;
	READ:
	for() {
		int ret;
		if( f ) {
			ret = wait_res(*f);
			reset(*f);
			f = 0p;
		} else {
			ret = cfa_recv(fd, (void*)it, count, 0, CFA_IO_LAZY);
		}
		// int ret = read(fd, (void*)it, count);
		if(ret == 0 ) {
			ret = close(fd);
			if( ret != 0 ) abort( "close in 'http read good' error: (%d) %s\n", (int)errno, strerror(errno) );
			return [OK200, true, 0, 0];
		}
		if(ret < 0 ) {
			if( errno == ECONNRESET || errno == EPIPE ) {
				ret = close(fd);
				if( ret != 0 ) abort( "close in 'http read bad' error: (%d) %s\n", (int)errno, strerror(errno) );
				return [E408, true, 0, 0];
			}
			abort( "read error: (%d) %s\n", (int)errno, strerror(errno) );
		}
		it[ret + 1] = '\0';
		rlen += ret;

		if( strstr( it, "\r\n\r\n" ) ) break;

		it += ret;
		count -= ret;

		if( count < 1 ) return [E414, false, 0, 0];
	}

	if( options.log ) {
		write(sout, buffer, rlen);
		sout | nl;
	}

	it = buffer;
	int ret = memcmp(it, "GET /", 5);
	if( ret != 0 ) return [E400, false, 0, 0];
	it += 5;

	char * end = strstr( it, " " );
	return [OK200, false, it, end - it];
}

//=============================================================================================

#include <clock.hfa>
#include <time.hfa>
#include <thread.hfa>

const char * original_http_msgs[] = {
	"HTTP/1.1 200 OK\nServer: HttpForall\nDate: %s \nContent-Type: text/plain\nContent-Length: ",
	"HTTP/1.1 200 OK\r\nServer: HttpForall\r\nConnection: keep-alive\r\nContent-Length: 15\r\nContent-Type: text/html\r\nDate: %s \r\n\r\nHello, World!\r\n",
	"HTTP/1.1 400 Bad Request\nServer: HttpForall\nDate: %s \nContent-Type: text/plain\nContent-Length: 0 \n\n",
	"HTTP/1.1 404 Not Found\nServer: HttpForall\nDate: %s \nContent-Type: text/plain\nContent-Length: 0 \n\n",
	"HTTP/1.1 405 Method Not Allowed\nServer: HttpForall\nDate: %s \nContent-Type: text/plain\nContent-Length: 0 \n\n",
	"HTTP/1.1 408 Request Timeout\nServer: HttpForall\nDate: %s \nContent-Type: text/plain\nContent-Length: 0 \n\n",
	"HTTP/1.1 413 Payload Too Large\nServer: HttpForall\nDate: %s \nContent-Type: text/plain\nContent-Length: 0 \n\n",
	"HTTP/1.1 414 URI Too Long\nServer: HttpForall\nDate: %s \nContent-Type: text/plain\nContent-Length: 0 \n\n",
};

struct date_buffer {
	https_msg_str strs[KNOWN_CODES];
};

thread DateFormater {
	int idx;
	date_buffer buffers[2];
};

void ?{}( DateFormater & this ) {
	((thread&)this){ "Server Date Thread" };
	this.idx = 0;
	memset( &this.buffers[0], 0, sizeof(this.buffers[0]) );
	memset( &this.buffers[1], 0, sizeof(this.buffers[1]) );
}

void main(DateFormater & this) {
	LOOP: for() {
		waitfor( ^?{} : this) {
			break LOOP;
		}
		or else {}


		char buff[100];
		Time now = timeHiRes();
		strftime( buff, 100, "%a, %d %b %Y %H:%M:%S %Z", now );
		// if( options.log ) sout | "Updated date to '" | buff | "'";

		for(i; KNOWN_CODES) {
			size_t len = snprintf( this.buffers[this.idx].strs[i].msg, 512, original_http_msgs[i], buff );
			this.buffers[this.idx].strs[i].len = len;
		}

		for(i; KNOWN_CODES) {
			https_msg_str * next = &this.buffers[this.idx].strs[i];
			__atomic_exchange_n((https_msg_str * volatile *)&http_msgs[i], next, __ATOMIC_SEQ_CST);
		}
		this.idx = (this.idx + 1) % 2;

		// if( options.log ) sout | "Date thread sleeping";

		sleep(1`s);
	}
}

//=============================================================================================
DateFormater * the_date_formatter;

void init_protocol(void) {
	the_date_formatter = alloc();
	(*the_date_formatter){};
}

void deinit_protocol(void) {
	^(*the_date_formatter){};
	free( the_date_formatter );
}