#include <stdio.h>
#include <string.h>
#include <stdarg.h>
#include <unistd.h>
#include <fcntl.h>
#include <time.h>
#include <errno.h>

#include <sys/stat.h>
#include <sys/file.h>

#include "stlfile.h"
#include "util.h"

#define MAXFILESIZE 1000000

struct command {
	const char *name;
	void (*func)(const char *);
	const char *desc;
};

int save_submission(struct parseinfo *info, char *data, int len);

void cat_cmd(const char *arg);
void help_cmd(const char *arg);
void exit_cmd(const char *arg);
void echo_cmd(const char *arg);
void upload_cmd(const char *arg);
void search_cmd(const char *arg);
void list_cmd(const char *arg);
void auth_cmd(const char *arg);

void cleanexit();

struct command commands[] = {
	{ "cat",    cat_cmd,    "Cat cmd go prrrrr." },
	{ "help",   help_cmd,   "You already know what this does." },
	{ "exit",   exit_cmd,   "Closes the session." },
	{ "echo",   echo_cmd,   "Repeat after me!" },
	{ "upload", upload_cmd, "Upload an STL file to analyze." },
	{ "search", search_cmd, "Search for an STL file by model name." },
	{ "list",   list_cmd,   "List your uploaded files." },
	{ "auth",   auth_cmd,   "Login to upload files to a private dir." }
};

struct parseinfo cached = { 0 };
char *resultdir;
int echo = 0, loggedin = 0;

int
save_submission(struct parseinfo *info, char *stldata, int stlsize)
{
	char *dirpath = NULL, *infopath = NULL, *modeldir = NULL,
	     *indexpath = NULL, *modelpath = NULL;
	FILE *f = NULL;
	int status = OK;

	modeldir = aprintf("%s%s-%i", loggedin ? "." : "",
			  info->hash, time(NULL));
	dirpath = aprintf("%s/%s", resultdir, modeldir);
	if (mkdir(dirpath, S_IRWXU | S_IRWXG | S_IRWXO)) goto fail;

	modelpath = aprintf("%s/%s", dirpath, "model");
	if (!(f = fopen(modelpath, "w+"))) goto fail;
	if (fwrite(stldata, 1, stlsize, f) != stlsize) goto fail;
	FCLOSE(f);

	infopath = aprintf("%s/%s", dirpath, "info");
	if (!(f = fopen(infopath, "w+"))) goto fail;
	if (save_info(info, f) != OK) goto fail;
	FCLOSE(f);

	indexpath = aprintf("%s/.index", resultdir);
	if (!(f = fopen(indexpath, "a+"))) goto fail;
	flock(fileno(f), LOCK_EX);
	fwrite(modeldir, 1, strlen(modeldir), f);
	fputc('\n', f);
	flock(fileno(f), LOCK_UN);
	FCLOSE(f);

exit:
	FCLOSE(f);

	free(dirpath);
	free(modelpath);
	free(infopath);
	free(indexpath);
	free(modeldir);

	return status;

fail:
	if (infopath) remove(infopath);
	if (modelpath) remove(modelpath);
	if (dirpath) remove(dirpath);

	status = FAIL;
	goto exit;
}

int
access_authorized(const char *file)
{
	return (loggedin && file[0] == '.' && file[1] != '.')
		|| (!loggedin && file[0] != '.');
}

int
handle_download(const char *scandir)
{
	char *infopath = NULL, *modelpath = NULL;
	size_t i, size;
	int status = OK;
	FILE *f;

	infopath = aprintf("%s/%s", scandir, "info");
	if (!(f = fopen(infopath, "r"))) {
		ERR("Selected result is missing!\n");
		goto fail;
	}

	free_info(&cached);
	if (load_info(&cached, f) != OK) {
		ERR("Failed to parse info file!\n");
		goto fail;
	}
	FCLOSE(f);

	print_info(&cached);

	if (strchr(ask("> Download model? "), 'y')) {
		modelpath = aprintf("%s/%s", scandir, "model");
		if (!(f = fopen(modelpath, "r"))) {
			ERR("Failed to access file!\n");
			goto fail;
		}
		fseek(f, 0, SEEK_END);
		size = ftell(f);
		fseek(f, 0, SEEK_SET);
		if (size >= MAXFILESIZE) {
			ERR("File is too large!\n");
			goto fail;
		}
		printf("Here you go.. (%liB)\n", size);
		while ((i = getc(f)) != EOF)
			putc(i, stdout);
		FCLOSE(f);
	}

exit:
	if (f) fclose(f);
	free(infopath);
	free(modelpath);
	return status;

fail:
	status = FAIL;
	goto exit;
}

void
motd()
{
	char linebuf[80];
	int msgc, msgi, i;
	FILE *f;

	if (!(f = fopen("msgs/motd", "r"))) return;

	if (!fgets(linebuf, sizeof(linebuf), f))
		goto exit;

	srand(time(NULL));
	if ((msgc = atoi(linebuf))) {
		msgi = rand() % msgc;
		for (i = 0; i < msgi + 1; i++)
			if (!fgets(linebuf, sizeof(linebuf), f))
				return;
		printf("%s\n", linebuf);
	}

exit:
	fclose(f);
}

void
cat_cmd(const char *arg)
{
	if (arg && !strncmp(arg, "flag", 4))
		dump("msgs/cat_flag");
	else
		printf("meow\n");
}

void
help_cmd(const char *arg)
{
	int i;

	for (i = 0; arg && i < ARRSIZE(commands); i++) {
		if (!strcmp(commands[i].name, arg)) {
			printf("%s\n", commands[i].desc);
			return;
		}
	}

	printf("Available commands:\n");
	for (i = 0; i < ARRSIZE(commands); i++)
		printf("%s%s", i ? " " : "", commands[i].name);
	printf("\n");
}

void
exit_cmd(const char *arg)
{
	printf("bye!\n");
	exit(0);
}

void
echo_cmd(const char *arg)
{
	echo ^= 1;
	printf("Echo is %s\n", echo ? "enabled" : "disabled");
}

void
upload_cmd(const char *arg)
{
	char *end, *contents = NULL, *modelname = NULL;
	const char *resp;
	size_t len;

	modelname = checkp(strdup(ask("> Model name: ")));
	if (!strlen(modelname)) {
		ERR("Empty model names are not allowed");
		goto exit;
	}

	resp = ask("> File size: ");
	len = strtoul(resp, &end, 10);
	if (len <= 0 || len >= MAXFILESIZE || *end) {
		ERR("Invalid file length!\n");
		goto exit;
	}

	printf("Ok! Im listening..\n");
	contents = checkp(malloc(len + 1));
	if (fread(contents, 1, len, stdin) != len) {
		ERR("Not enough data received!\n");
		goto exit;
	}
	contents[len] = '\0';

	if ((cached.valid = parse_file(&cached, contents, len, &modelname))) {
		if (save_submission(&cached, contents, len) != OK)
			ERR("Failed to save your submission!\n");
		else
			printf("Your file was saved with ID %s!\n", cached.hash);
	}

exit:
	free(contents);
	free(modelname);
}

void
search_cmd(const char *arg)
{
	const char *hash, *resp = NULL;
	char *indexpath = NULL, *seldir = NULL;
	FILE *f;
	int i, c, matchlen, reslen;

	if (arg && !strcmp(arg, "last")) {
		if (!cached.valid) {
			ERR("No cached info report available\n");
			return;
		}
		hash = cached.hash;
	} else {
		hash = mhash(arg ? arg : ask("> Model name: "), -1);
	}

	indexpath = aprintf("%s/.index", resultdir);
	if (!(f = fopen(indexpath, "r"))) {
		ERR("Sorry, no files currently available\n");
		goto exit;
	}
	flock(fileno(f), LOCK_SH);

	reslen = matchlen = 0;
	while ((c = fgetc(f)) > 0) {
		if (c == '\n') {
			matchlen = 0;
			continue;
		} else if (matchlen == -1) {
			continue;
		} else if (!matchlen && c == '.') {
			if (!loggedin) matchlen = -1;
			continue;
		} else if (c == hash[matchlen]) {
			matchlen += 1;
		} else {
			matchlen = -1;
		}

		if (matchlen == strlen(hash)) {
			fseek(f, -matchlen, SEEK_CUR);
			putchar(' ');
			if (loggedin) putchar('.');
			while ((c = fgetc(f)) > 0 && c != '\n')
				putchar(c);
			putchar('\n');
			matchlen = 0;
			reslen += 1;
		}
	}

	flock(fileno(f), LOCK_UN);
	fclose(f);

	if (!reslen) {
		ERR("Sorry, no files matching that name\n");
		goto exit;
	}

	while (1) {
		resp = ask("> Enter %s [q to quit]: ",
			   resp ? "another" : "hash");
		if (strchr(resp, 'q')) break;
		if (checkalph(resp, ".abcdef0123456789-") != OK) {
			ERR("Invalid model id specified\n");
			goto exit;
		}

		seldir = aprintf("%s/%s", resultdir, resp);
		if (handle_download(seldir) != OK) goto exit;
		FREE(seldir);
	}

exit:
	free(seldir);
	free(indexpath);
	return;
}

void
list_cmd(const char *arg)
{
	struct parseinfo info;
	char buf[256], *path;
	FILE *f, *fn;

	if (!loggedin) {
		ERR("Not logged in!\n");
		return;
	}

	path = aprintf("%s/.index", resultdir);
	if (!(f = fopen(path, "r"))) {
		ERR("Failed to get files index\n");
		free(path);
		return;
	}
	free(path);

	flock(fileno(f), LOCK_SH);
	while (fgets(buf, sizeof(buf), f)) {
		if (*buf && buf[strlen(buf)-1] == '\n')
			buf[strlen(buf)-1] = '\0';

		printf(">> %s\n", buf);
		path = aprintf("%s/%s/info", resultdir, buf);
		if ((fn = fopen(path, "r")) && load_info(&info, fn) == OK) {
			print_info(&info);
			free_info(&info);
		} else {
			ERR("Failed to read file info!\n");
		}
		if (fn) fclose(f);
		free(path);
	}
	flock(fileno(f), LOCK_UN);
	fclose(f);
}

void
auth_cmd(const char *arg)
{
	const char *hash;
	char *ndir, *indexpath;
	int ret;
	FILE *f;

	if (loggedin) {
		ERR("Already logged in!\n");
		return;
	}

	hash = mhash(arg ? arg : ask("> Enter a password: "), -1);
	ndir = aprintf("%s/.%s", resultdir, hash);
	ret = mkdir(ndir, S_IRWXU | S_IRWXG | S_IRWXO);
	if (!ret) {
		printf("Success!\n");
	} else if (ret && errno == EEXIST) {
		printf("Success!\nWelcome back!\n");
	} else {
		ERR("Auth failed!\n");
		return;
	}

	if (errno != EEXIST) {
		indexpath = aprintf("%s/.index", resultdir);
		if (!(f = fopen(indexpath, "a+"))) {
			free(indexpath);
			ERR("Auth failed!\n");
			return;
		}
		flock(fileno(f), LOCK_EX);
		fputc('.', f);
		fwrite(hash, 1, strlen(hash), f);
		fputc('\n', f);
		flock(fileno(f), LOCK_UN);
		fclose(f);
		free(indexpath);
	}

	free(resultdir);
	resultdir = ndir;
	loggedin = 1;
	free_info(&cached);
}

void
cleanexit()
{
	free_info(&cached);
	free(resultdir);
}

int
main()
{
	const char *cmd, *envstr;
	int exit, i, cmdlen;
	char *cp, *arg;

	if (!(envstr = getenv("RESULTDIR")))
		die("RESULTDIR not defined\n");

	resultdir = checkp(strdup(envstr));

	setvbuf(stdin, NULL, _IONBF, 0);
	setvbuf(stdout, NULL, _IONBF, 0);
	setvbuf(stderr, NULL, _IONBF, 0);

	atexit(cleanexit);

	dump("msgs/banner");
	motd();

	exit = 0;
	while (!exit) {
		errno = 0;
		cmd = ask("\r$ ");
		if (!*cmd && errno == EBADMSG) break;
		if (!*cmd) continue;

		cp = strchr(cmd, ' ');
		arg = cp ? cp + 1 : NULL;
		cmdlen = cp ? cp - cmd : strlen(cmd);

		for (i = 0; i < ARRSIZE(commands); i++) {
			if (!strncmp(commands[i].name, cmd, cmdlen)
					&& !commands[i].name[cmdlen]) {
				commands[i].func(arg);
				break;
			}
		}

		if (i == ARRSIZE(commands) && strlen(cmd) != 0)
			ERR("No such command!\n");
	}

	return EXIT_SUCCESS;
}