#include "http.h"

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

const char * status_str[] = {
	[STATUS_OK] = "200 OK",
	[STATUS_BAD_REQUEST] = "400 Bad Request",
	[STATUS_METHOD_NOT_ALLOWED] = "405 Method Not Allowed",
	[STATUS_REQUEST_TIMEOUT] = "408 Request Timeout",
	[STATUS_INTERNAL_SERVER_ERROR] = "500 Internal Server Error",
	[STATUS_NOT_IMPLEMENTED] = "501 Not Implemented",
	[STATUS_VERSION_NOT_SUPPORTED] = "505 Version Not Supported",
};

/// Sends a simple response only with a status to the client.
/// \param fd File descriptor of the client socket
/// \param status HTTP response status code
/// \return Negative value if an error was encountered; numbers of bytes written otherwise
int respond_only_status(const int fd, const enum status status)
{
	static const char * pattern =
		"HTTP/1.1 %s\r\n"
		"Connection: close\r\n"
		"\r\n";

	return dprintf(fd, pattern, status_str[status]);
}

/// Sends a response with a status and a body to the client.
/// \param fd File descriptor of the client socket
/// \param status HTTP response status code
/// \param body Content that will be sent
/// \param size Size of the content in bytes
/// \return Negative value if an error was encountered; numbers of bytes written otherwise
int respond_with_body(const int fd, const enum status status, const char * body, const int size)
{
	static const char * pattern =
		"HTTP/1.1 %s\r\n"
		"Connection: close\r\n"
		"Content-Type: application/json\r\n"
		"Content-Size: %d\r\n"
		"\r\n";

	if (0 > dprintf(fd, pattern, status_str[status], size))
	{
		return -1; // TODO: Handle errors properly
	}

	return write(fd, body, size);
}

/// Collects request between calls to `poll`.
/// \param fd Client socket
/// \param request Buffer with the request content
/// \return Number of bytes parsed, -1 if an error occured or 0 if expects more data
int collect_request(const int fd, char ** request)
{
	static const int size = 4096;

	if (NULL == *request)
	{
		*request = malloc(size);
		if (NULL == *request)
		{
			return -1;
		}
	}

	// TODO: Expand buffer until EAGAIN or arbitrary limit
	int length = read(fd, *request, size - 1);

	if (0 == length || (-1 == length && EWOULDBLOCK != errno && EAGAIN != errno))
	{
		return -1; // TODO: Handle errors properly
	}

	(*request)[length] = 0;

	return length;
}