#include "assets.h"
#include "json_curl.h"
#include "quotes.h"
#include "tda.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <json-c/json.h>

static json_object *tda_init_req(struct tda_session *sess,
	const char *refresh_token)
{
	json_object *json = NULL;
	CURL *curl = curl_easy_init();
	if (!curl) return NULL;
	char *esc = curl_easy_escape(curl, refresh_token, 0);
	if (!esc) goto err_free_curl;

	char buf[4096] = { 0 };
	char fmt[] = "client_id=%s&grant_type=refresh_token&access_type=offline&"
		"refresh_token=%s";
	int c = snprintf(buf, sizeof(buf), fmt, sess->client_id, esc);
	if (c < 0 || (unsigned)c >= sizeof(buf) ||
		curl_easy_setopt(curl, CURLOPT_POSTFIELDS, buf) != CURLE_OK)
		goto err_free_esc;

	json = json_curl_perform(curl,
		"https://api.tdameritrade.com/v1/oauth2/token");

err_free_esc:
	curl_free(esc);
err_free_curl:
	curl_easy_cleanup(curl);
	return json;
}

struct tda_session *tda_init(const char *client_id, const char *account_id,
	const char *refresh_token)
{
	struct tda_session *sess = calloc(1, sizeof(*sess));
	if (!sess) return NULL;

	json_object *json;
	if (!((sess->client_id = strdup(client_id)) &&
			(sess->account_id = strdup(account_id)) &&
			(json = tda_init_req(sess, refresh_token))))
		goto err_free_sess;

	json_object *tmp = json;
	int err = !json_object_object_get_ex(json, "refresh_token", &tmp) ||
		!(sess->refresh_token = strdup(json_object_get_string(tmp))) ||
		!json_object_object_get_ex(json, "access_token", &tmp) ||
		!(sess->access_token = strdup(json_object_get_string(tmp)));
	json_object_put(json);
	if (err) goto err_free_sess;

	return sess;

err_free_sess:
	tda_cleanup(sess);
	return NULL;
}

void tda_cleanup(struct tda_session *sess)
{
	free(sess->client_id);
	free(sess->account_id);
	free(sess->access_token);
	free(sess->refresh_token);
	free(sess);
}

static json_object *oauth_json_curl(struct tda_session *sess, const char *uri)
{
	CURL *curl = curl_easy_init();
	if (!curl) return NULL;

	json_object *json = NULL;
	if (curl_easy_setopt(curl, CURLOPT_HTTPAUTH,
			CURLAUTH_BEARER) == CURLE_OK &&
		curl_easy_setopt(curl, CURLOPT_XOAUTH2_BEARER,
			sess->access_token) == CURLE_OK)
		json = json_curl_perform(curl, uri);

	curl_easy_cleanup(curl);
	return json;
}

static json_object *fetch_positions(struct tda_session *sess)
{
	char uri[2048];
	int c = snprintf(uri, sizeof(uri),
		"https://api.tdameritrade.com/v1/accounts/%s?fields=positions",
		sess->account_id);
	if (c < 0 || (unsigned)c >= sizeof(uri))
		return NULL;

	return oauth_json_curl(sess, uri);
}

static json_object *fetch_quotes(struct tda_session *sess, const char *symbols)
{
	char uri[2048];
	int c = snprintf(uri, sizeof(uri),
		"https://api.tdameritrade.com/v1/marketdata/quotes?symbol=%s",
		symbols);
	if (c < 0 || (unsigned)c >= sizeof(uri))
		return NULL;

	return oauth_json_curl(sess, uri);
}

static struct asset *gen_asset(json_object *json)
{
	json_object *tmp;

	if (!json_object_object_get_ex(json, "instrument", &tmp) ||
		!json_object_object_get_ex(tmp, "assetType", &tmp))
		return NULL;

	const char *type = json_object_get_string(tmp);
	enum asset_type at;
	if (strcmp(type, "EQUITY") == 0)
		at = STOCK;
	else if (strcmp(type, "OPTION") == 0)
		at = OPTION;
	else
		return NULL;

	struct asset *a = calloc(1, sizeof(*a));
	if (!a) return NULL;
	a->type = at;

	if (!json_object_object_get_ex(json, "longQuantity", &tmp))
		goto err;
	a->amt = json_object_get_double(tmp);

	if (!json_object_object_get_ex(json, "instrument", &tmp) ||
		!json_object_object_get_ex(tmp, "symbol", &tmp) ||
		!(a->symbol = strdup(json_object_get_string(tmp))))
		goto err;

	return a;

err:
	free(a);
	return NULL;
}

int tda_load_assets(struct tda_session *sess, struct asset **assets)
{
	json_object *tmp, *json = fetch_positions(sess);
	if (!json ||
		!json_object_object_get_ex(json, "securitiesAccount", &tmp) ||
		!json_object_object_get_ex(tmp, "positions", &tmp))
		return -1;

	int n = 0;

	for (size_t i = 0; i < json_object_array_length(tmp); ++i) {
		json_object *p_json = json_object_array_get_idx(tmp, i);
		struct asset *a = gen_asset(p_json);
		if (a) assets[n++] = a;
	}

	json_object_put(json);
	return n;
}

int tda_get_quote_symbols(struct asset **assets, int n, char **bufptr)
{
	size_t bufsize = 1024;
	char *buf = malloc(bufsize);
	if (!buf) return -1;
	int len = 0;

	for (int i = 0; i < n; ++i) {
		if (assets[i]->type != CRYPTO) {
retry:;
			char *tmp = memccpy(buf + len, assets[i]->symbol, '\0',
				bufsize - len - 1); // -1 for ','
			if (tmp) {
				len = tmp - buf;
				buf[len - 1] = ',';
			} else {
				char *tmpbuf = realloc(buf, (bufsize *= 2));
				if (tmpbuf) {
					buf = tmpbuf;
				} else {
					free(buf);
					return -1;
				}

				goto retry;
			}
		}
	}

	buf[--len] = '\0';
	*bufptr = buf;
	return len;
}

static struct quote *gen_quote(const json_object *json)
{
	struct quote *q = calloc(1, sizeof(*q));
	if (!q) return NULL;

	json_object *tmp;
	if (!json_object_object_get_ex(json, "symbol", &tmp) ||
		!(q->symbol = strdup(json_object_get_string(tmp))) ||
		!(q->currency = strdup("USD")))
		goto err;

	if (json_object_object_get_ex(json, "lastPrice", &tmp))
		q->price = json_object_get_double(tmp);
	if (json_object_object_get_ex(json, "multiplier", &tmp))
		q->multiplier = json_object_get_double(tmp);
	if (json_object_object_get_ex(json, "netPercentChangeInDouble", &tmp))
		q->change_percent = json_object_get_double(tmp);

	return q;

err:
	quote_free(q);
	return NULL;
}

int tda_get_quotes(struct tda_session *sess, const char *symbols,
	struct quote ***quotes_ptr)
{
	json_object *json = fetch_quotes(sess, symbols);
	if (!json) return -1;

	int n = 0;
	struct lh_table *table = json_object_get_object(json);
	struct quote **quotes = calloc(table->count, sizeof(*quotes));
	if (!quotes) {
		json_object_put(json);
		return -1;
	}

	for (struct lh_entry *entry = table->head; entry; entry = entry->next) {
		struct quote *q = gen_quote(entry->v);
		if (q) quotes[n++] = q;
	}

	json_object_put(json);
	*quotes_ptr = quotes;
	return n;
}