/*
 * This software has been authored by an employee or employees of Los
 * Alamos National Security, LLC, operator of the Los Alamos National
 * Laboratory (LANL) under Contract No. DE-AC52-06NA25396 with the U.S.
 * Department of Energy.  The U.S. Government has rights to use,
 * reproduce, and distribute this software.  The public may copy,
 * distribute, prepare derivative works and publicly display this
 * software without charge, provided that this Notice and any statement
 * of authorship are reproduced on all copies.  Neither the Government
 * nor LANS makes any warranty, express or implied, or assumes any
 * liability or responsibility for the use of this software.  If
 * software is modified to produce derivative works, such modified
 * software should be clearly marked, so as not to confuse it with the
 * version available from LANL.
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <ctype.h>

char *BASE_PATH = "";

struct {
	char *name;
	size_t size;
} entries[] = {
	{
	"name", 20}, {
	"author", 80}, {
	"color", 10}, {
	"program", 16384}, {
	NULL, 0}
};


size_t inlen;

int
read_char()
{
	if (inlen) {
		inlen -= 1;
		return getchar();
	}
	return EOF;
}

char
tonum(int c)
{
	if ((c >= '0') && (c <= '9')) {
		return c - '0';
	}
	if ((c >= 'a') && (c <= 'f')) {
		return 10 + c - 'a';
	}
	if ((c >= 'A') && (c <= 'F')) {
		return 10 + c - 'A';
	}
	return 0;
}

char
read_hex()
{
	int a = read_char();
	int b = read_char();

	return tonum(a) * 16 + tonum(b);
}

/*
 * Read a key or a value.  Since & and = aren't supposed to appear outside of boundaries, we can use the same function for both. 
 */
size_t
read_item(char *str, size_t maxlen)
{
	int c;
	size_t pos = 0;

	while (1) {
		c = read_char();
		switch (c) {
		case EOF:
		case '=':
		case '&':
			str[pos] = '\0';
			return pos;
		case '%':
			c = read_hex();
			break;
		case '+':
			c = ' ';
			break;
		}
		if (pos < maxlen - 1) {
			str[pos] = c;
			pos += 1;
		}
	}
}

size_t
copy_item(char *filename, size_t maxlen)
{
	FILE *f;
	char path[132];
	int c;
	size_t pos = 0;

	snprintf(path, sizeof(path), "%s%05d.%s", BASE_PATH, getpid(), filename);
	f = fopen(path, "w");
	if (!f) {
		/*
		 * Just send it to the bit bucket 
		 */
		maxlen = 0;
	}

	while (1) {
		c = read_char();
		switch (c) {
		case EOF:
		case '=':
		case '&':
			if (f)
				fclose(f);
			return pos;
		case '%':
			c = read_hex();
			break;
		case '+':
			c = ' ';
			break;
		}
		if (pos < maxlen) {
			fputc(c, f);
			pos += 1;
		}
	}
}

int
croak(int code, char *msg)
{
	int i;
	char path[132];

	for (i = 0; entries[i].name; i += 1) {
		snprintf(path, sizeof(path), "%s%05d.%s", BASE_PATH, getpid(), entries[i].name);
		unlink(path);
	}

	printf("Status: %d %s\n", code, msg);
	printf("Content-type: text/plain\n");
	printf("\n");
	printf("Error: %s\n", msg);

	return 0;
}

int
main(int argc, char *argv[])
{
	int sensor[10][4];
	char key[20];
	char token[40];
	size_t len;

	memset(sensor, 0, sizeof(sensor));
	token[0] = '\0';

	BASE_PATH = getenv("BASE_PATH");
	if (!BASE_PATH) {
		BASE_PATH = "";
	}

	{
		char *rm = getenv("REQUEST_METHOD");

		if (!(rm && (0 == strcmp(rm, "POST")))) {
			printf("405 Method not allowed\n");
			printf("Allow: POST\n");
			printf("Content-type: text/plain\n");
			printf("\n");
			printf("Error: I only speak POST\n");
			return 0;
		}

		inlen = atoi(getenv("CONTENT_LENGTH"));
	}

	while (inlen) {
		len = read_item(key, sizeof(key));
		if (0 == strcmp(key, "token")) {
			read_item(token, sizeof(token));
		} else if ((3 == len) && ('s' == key[0])) {
			/*
			 * sensor dealie, key = "s[0-9][rawt]" 
			 */
			char val[5];
			int n = key[1] - '0';
			int i;
			int p;

			read_item(val, sizeof(val));

			if (!(n >= 0) && (n <= 9)) {
				break;
			}
			i = atoi(val);

			switch (key[2]) {
			case 'r':
				p = 0;
				break;
			case 'a':
				p = 1;
				break;
			case 'w':
				p = 2;
				break;
			default:
				p = 3;
				i = (val[0] != '\0');
				break;
			}

			sensor[n][p] = i;
		} else {
			int i;

			for (i = 0; entries[i].name; i += 1) {
				if (0 == strcmp(key, entries[i].name)) {
					len = copy_item(key, entries[i].size);
					break;
				}
			}
		}
	}

	/*
	 * Sanitize token 
	 */
	{
		char *p = token;

		while (*p) {
			if (!isalnum(*p)) {
				*p = '_';
			}
			p += 1;
		}

		if ('\0' == token[0]) {
			token[0] = '_';
			token[1] = '\0';
		}
	}

	/*
	 * Move files into their directory 
	 */
	{
		char path[132];
		char dest[132];
		struct stat st;
		int i;

		snprintf(path, sizeof(path), "%s%s/", BASE_PATH, token);
		if (-1 == stat(path, &st))
			return croak(422, "Invalid token");
		if (!S_ISDIR(st.st_mode))
			return croak(422, "Invalid token");
		for (i = 0; entries[i].name; i += 1) {
			snprintf(path, sizeof(path), "%s%05d.%s", BASE_PATH, getpid(), entries[i].name);
			snprintf(dest, sizeof(dest), "%s%s/%s", BASE_PATH, token, entries[i].name);
			rename(path, dest);
		}

		for (i = 0; i < 10; i += 1) {
			FILE *f;

			snprintf(dest, sizeof(dest), "%s%s/sensor%d", BASE_PATH, token, i);
			f = fopen(dest, "w");
			if (!f)
				break;

			fprintf(f, "%d %d %d %d\n", sensor[i][0], sensor[i][1], sensor[i][2], sensor[i][3]);
			fclose(f);
		}
	}

	printf("Content-type: text/plain\n");
	printf("\n");
	printf("OK: Tank submitted!\n");

	return 0;
}