/***********************************************************
 * Get Stock Price 
 *
 * Program to get the value of any stock available from 
 * www.google.com/finance/quote/#######
 *
 * REQUIRES: ddgr, wget
 *
 * program: get_stock_price 
 * author : yetimach
 * date   : June 08, 2022
 *
 * Usage: get_stock_price STOCK NAME
 *
 ************************************************************/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <dirent.h>
#include <errno.h>

#define MAX_CH 200 // max chars, used for various strings
#define MAX_C 30 // smaller max chars--I don't know why : D

#define SP "data-last-price=\""     //search pattern
#define D '#'  //delimiter for separating strings with white space

FILE *wdf; //wget dump file
	
char temp_num_st[MAX_C]; // temporary number string
float temp_num_float;
char g_temp_sn[MAX_CH]; // global temp stock name
char g_temp_url[MAX_CH]; // global temp url
float g_csp = 0; //global current stock price


float get_price_after_pat(FILE *file, char *pattern){
	float price;
	int pattern_len = 0;
	char num_str[MAX_C];
	char ch;
	while ((ch = pattern[pattern_len++]) != '\0')
		;
	--pattern_len;
	int matches = 0;
	int sp = 0;
	while ((ch = getc(wdf)) != EOF){
		if (ch != pattern[matches])
			matches = 0;
		else
			++matches;
		if (matches == pattern_len)
			break;
	}
		if (ch == EOF)
			return -1;
	for (int i = 0; i < 10; i++){
		ch = getc(wdf);
		if (isdigit(ch) || ch == '.')
			num_str[sp++] = ch;
	}
	price = atof(num_str);
	return (price > 0) ? price : -1;
}

int is_valid_url(char *the_url){
	int i;
	char temp_the_url[MAX_CH];
	char *good_url ="www.google.com/finance/quote/";
	// the idea here is to put the first 29 chars into temp_the_url
	for (i = 0; i < 29; i++)
		temp_the_url[i] = the_url[i];
	temp_the_url[i] = '\0';
	return ((strcmp(temp_the_url, good_url)) == 0) ? 1 : -1;
}

// use ddgr to generate a file with the correct name and url for a given stock
// nos = name of stock
int get_correct_n_and_u(char *nos){
	char path[MAX_CH];
	strcpy(path, getenv("HOME"));
	strcat(path, "/.gfst/gfst_temp_file.txt");
	char ddgr_cmd[MAX_CH] = "ddgr -n=1 -x --np google finance quote ";
	strcat(ddgr_cmd, nos);
	strcat(ddgr_cmd, " > ");
	strcat(ddgr_cmd, path);
	system(ddgr_cmd);
	FILE *gfst_temp_file = fopen(path, "r");
	char sn[MAX_CH]; //correct stock name
	char snt[MAX_CH]; //correct stock name temp
	int si = 0; //string index
	// the first line in the file is the stock name (hopefully)
	while ((snt[si++] = getc(gfst_temp_file)) != '\n')
		;
	si = 0;
	char url[MAX_CH]; //correct url
	char urlt[MAX_CH]; //correct url temp
	// the second line in the file is the google finance url (hopefully)
	while ((urlt[si++] = getc(gfst_temp_file)) != '\n')
		;
	si = 0;
	// time to clean up the name, remove "1. " from the beginning and
	// cut it at the final ")"
	while (!isalpha(snt[si++]))
		if (si > 199)
			break;
	--si;
	int si2 = 0;
	while ((sn[si2++] = snt[si++]) != ')')
		if (si2 > 199)
			break;
	sn[si2] = '\0';
	char ch;
	si = 0;
	si2 = 0;
	while ((ch = urlt[si++]) != 'w')
		if (si > 199)
			break;
	--si;
	while ((url[si2++] = urlt[si++]) != ' ')
		if (si > 199)
			break;
	--si2;
	url[si2] = '\0';
	int counter = 0;
	//remove the mystery newline...
	while (url[counter++] != '\0'){
		if (url[counter-1] == '\n')
			url[counter-1] = '\0';
	}
	int success = is_valid_url(url);
	if (success){
	strcpy(g_temp_sn, sn);
	strcpy(g_temp_url, url);
	}
	char rm_cmd[MAX_CH] = "rm ";
	strcat(rm_cmd, path);
	system(rm_cmd);
	return success;
}

		
float get_current_st_price(char *gf_url){
	char wdfp[MAX_CH]; //wget dump file path
	strcpy(wdfp, getenv("HOME"));
	strcat(wdfp, "/.gfst/wget_dump_file.txt");
	char touch_cmd[MAX_CH] = "touch ";
	strcat(touch_cmd, wdfp);
	system(touch_cmd);
	char wget_cmd[MAX_CH] = "wget ";
	strcat(wget_cmd, gf_url);
	strcat(wget_cmd, " -q -O ");
	strcat(wget_cmd, wdfp);
	system(wget_cmd);
	wdf = fopen(wdfp, "r");
	float csp = get_price_after_pat(wdf, SP);
	return csp;
}

int main(int argc, char *argv[])
{
	if (argc >= 2){
		char search_term[MAX_CH] = "";
		int word = 1;
		while (argc-- >= 2){
			strcat(search_term, argv[word++]);
			if (argc + 1 != 2)
				strcat(search_term, " ");
		}
		char gfst_dir[MAX_CH];
		strcpy(gfst_dir, getenv("HOME"));
		strcat(gfst_dir, "/.gfst");
		DIR* dir = opendir(gfst_dir);
		if (dir) {
			// HOME/.gfst exists
			closedir(dir);
		} else if (ENOENT == errno) {
			char mkdir_cmd[MAX_CH] = "mkdir ";
			strcat(mkdir_cmd, gfst_dir);
			system(mkdir_cmd);
		} else {
			printf("\n\tUnknown error : (\n\n");
			return -1;
		}		
		int check = get_correct_n_and_u(search_term);		
		if (check == -1 || g_csp == -1){
			printf("\n\tBummer, couldn't find a stock called \"%s\".\n\n", search_term);
			return 0;
		}
		g_csp = get_current_st_price(g_temp_url);
		if (g_csp == -1){
			printf("\n\tBummer, couldn't find a stock called \"%s\".\n\n", search_term);
			return 0;
		}
		printf("\n\t%s\n\t$%.2f\n\n", g_temp_sn, g_csp);
	}else
		printf("\n\tUsage: get_stock_price STOCK NAME\n\n");
	return 0;
}