#define _BSD_SOURCE /* Needed for popen(3) on Linux. */
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <dirent.h>
#include <unistd.h>
#include "config.h"

char *url = "https://sdccd.instructure.com/api/v1/users/self/files";

char *
json_match(char *JSON, char *key)
{
	char *p = strstr(JSON, key);
	if (p == NULL) {
		return NULL;
	}
	p += strlen(key) + strlen("\":\"");
	int len = 0, i;
	for (i = 0; p[i] != '\0' && p[i] != '"'; i++) {
		len++;
	}
	char *val = calloc(len + 1, sizeof(char));
	for (i = 0; i < len; i++) {
		val[i]= p[i];
	}
	val[len] = '\0';
	return val;
}

char *
strip_fn(char *path)
{
	char *dir = calloc(strlen(path) + 1, sizeof(char));
	strcpy(dir, path);
	int i;
	for (i = strlen(path) - 1; i >= 0; i--) {
		if (dir[i] == '/') {
			dir[i] = '\0';
			return dir;
		}
	}
	dir[0] = '\0';
	return dir;
}

int
upfile(char *name, char *rdir)
{
	printf("%s/%s\n", rdir, name);
	char *cmd = calloc(cmdsize, sizeof(char));
	char *dir = strip_fn(name);
	snprintf(cmd, cmdsize, "curl -s '%s' -F 'name=%s'"
		" -F 'parent_folder_path=%s/%s'"
		" -H 'Authorization: Bearer %s'", url, name,
		rdir, dir, upload_key);

	FILE *auth = popen(cmd, "r");
	char *JSON = NULL;
	int len = 0;
	char ch;
	while ((ch = fgetc(auth)) > 0) {
		len++;
		JSON = realloc(JSON, len * sizeof(char));
		JSON[len - 1] = ch;
	}
	len++;
	JSON = realloc(JSON, len * sizeof(char));
	/* Test output.
	JSON = "{\"file_param\":\"file\",\"progress\":null,\"upload_url\":\"https://inst-fs-iad-prod.inscloudgate.net/files?token=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzUxMiJ9.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.emC3105zbRiley3teCUsym5jVLmOePaENMahQ-MQRthgawN0GAuG9ufUYyk0l7hrXKy2WYaO0v3m6pmIkA3s4w\",\"upload_params\":{\"filename\":\"test.txt\",\"content_type\":\"text/plain\"}}";*/

	char *upload_url = json_match(JSON, "upload_url");
	char *content_type = json_match(JSON, "content_type");
	char *filename = json_match(JSON, "filename");

	if (upload_url == NULL || content_type == NULL
		|| filename == NULL) {
		fprintf(stderr, "Something went wrong with"
			"authentification.\n%s\n", JSON);
		return -1;
	}

	snprintf(cmd, cmdsize, "curl -s '%s' -F 'key=%s'"
		" -F 'content_type=%s' -F 'file=@%s'",
		upload_url, filename, content_type, name);
	/* Throw away output; assume that, if auth is successful,
	then upload is successful too. */
	popen(cmd, "r");

	free(upload_url);
	free(content_type);
	free(filename);
	free(dir);
	free(cmd);
	return 0;
}

int
updir(DIR *dirp, char *rdir, char *dir)
{
	DIR *nestdirp;
	struct dirent *dp;
	char *name = calloc(pathsize, sizeof(char));
	while ((dp = readdir(dirp)) != NULL) {
		if (strcmp(".", dp->d_name) == 0
			|| strcmp("..", dp->d_name) == 0)
			continue;
		if (strcmp(".", dir) != 0) {
			strcpy(name, dir);
			if (name[strlen(name) - 1] != '/')
				strcat(name, "/");
			strcat(name, dp->d_name);
		}
		else
			strcpy(name, dp->d_name);
		nestdirp = opendir(name);
		if (nestdirp == NULL)
			upfile(name, rdir);
		else if (nestdirp != NULL) {
			updir(nestdirp, rdir, name);
		}
	}

	free(name);
	closedir(dirp);
	return 0;
}

int
main(int argc, char **argv)
{
	upload_key = getenv("CANKEY");
	if (upload_key == NULL) {
		fprintf(stderr, "Provide a valid key in the"
			" environment variable CANKEY.\nUsing a POSIX shell,"
			" do this in ~/.profile.\n"
			" Using rc, do this in $home/lib/profile.\n");
		return -1;
	}
	char *rdir;
	rdir = calloc(pathsize, sizeof(char));
	char *local;
	local = calloc(pathsize, sizeof(char));
	local[0] = '.';
	int i;
	for (i = 1; i < argc; ++i) {
		if (strcmp(argv[i], "-r") == 0) {
			if (i < argc - 1) {
				++i;
				rdir = argv[i];
			}
			else {
				puts("Supply a directory"
					" name after -r");
				return 1;
			}
		} else if (strcmp(argv[i], "-f") == 0) {
			if (i < argc - 1) {
				++i;
				local = argv[i];
			}
			else {
				puts("Supply a file or directory"
					" name after -f");
				return 2;
			}
		}
		else {
			puts(argv[i]);
			printf("%s [-r remote directory]"
				" [-f local file or directory]\n",
				argv[0]);
			return -1;
		}
	}

	DIR *dirp = opendir(local);
	if (dirp != NULL) {
		updir(dirp, rdir, local);
	} else if (access(local, R_OK) == 0) {
		upfile(local, rdir);
	} else {
		printf("I can't open this!\n");
		return 3;
	}

	return 0;
}