/*!
 * restd_http_handler.h
 *
 * Copyright (c) 2015-2019, NADAL Jean-Baptiste. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02110-1301 USA
 * 
 * @Author:  NADAL Jean-Baptiste
 * @Date: 23/12/2019
 *
 */

#ifndef _RESTD_HTTP_HANDLER_H
#define _RESTD_HTTP_HANDLER_H

/*------------------------------- INCLUDES ----------------------------------*/

/*----------------------------------------------------------------------------*\
|                           HTTP PROTOCOL SPECIFICS                            |
\*----------------------------------------------------------------------------*/

/* HTTP PROTOCOL CODES */
#define HTTP_PROTOCOL_09 "HTTP/0.9"
#define HTTP_PROTOCOL_10 "HTTP/1.0"
#define HTTP_PROTOCOL_11 "HTTP/1.1"

/* HTTP RESPONSE CODES */
#define HTTP_NO_RESPONSE (0)
#define HTTP_CODE_CONTINUE (100)
#define HTTP_CODE_OK (200)
#define HTTP_CODE_CREATED (201)
#define HTTP_CODE_NO_CONTENT (204)
#define HTTP_CODE_PARTIAL_CONTENT (206)
#define HTTP_CODE_MULTI_STATUS (207)
#define HTTP_CODE_MOVED_TEMPORARILY (302)
#define HTTP_CODE_NOT_MODIFIED (304)
#define HTTP_CODE_Brestd_REQUEST (400)
#define HTTP_CODE_UNAUTHORIZED (401)
#define HTTP_CODE_FORBIDDEN (403)
#define HTTP_CODE_NOT_FOUND (404)
#define HTTP_CODE_METHOD_NOT_ALLOWED (405)
#define HTTP_CODE_REQUEST_TIME_OUT (408)
#define HTTP_CODE_GONE (410)
#define HTTP_CODE_REQUEST_URI_TOO_LONG (414)
#define HTTP_CODE_LOCKED (423)
#define HTTP_CODE_INTERNAL_SERVER_ERROR (500)
#define HTTP_CODE_NOT_IMPLEMENTED (501)
#define HTTP_CODE_SERVICE_UNAVAILABLE (503)

/* DEFAULT BEHAVIORS */
#define HTTP_CRLF "\r\n"
#define HTTP_DEF_CONTENTTYPE "application/octet-stream"

/*----------------------------------------------------------------------------*\
|                                 TYPEDEFS                                     |
\*----------------------------------------------------------------------------*/
typedef struct restd_http_s restd_http_t;

/*!< Hook type */
#define RESTD_HOOK_ALL (0)                    /*!< call on each and every phases */
#define RESTD_HOOK_ON_CONNECT (1)             /*!< call right after the establishment of connection */
#define RESTD_HOOK_AFTER_REQUESTLINE (1 << 2) /*!< call after parsing request line */
#define RESTD_HOOK_AFTER_HEADER (1 << 3)      /*!< call after parsing all headers */
#define RESTD_HOOK_ON_BODY (1 << 4)           /*!< call on every time body data received */
#define RESTD_HOOK_ON_REQUEST (1 << 5)        /*!< call with complete request */
#define RESTD_HOOK_ON_CLOSE (1 << 6)          /*!< call right before closing or next request */

enum restd_http_request_status_e
{
    RESTD_HTTP_REQ_INIT = 0,         /*!< initial state */
    RESTD_HTTP_REQ_REQUESTLINE_DONE, /*!< received 1st line */
    RESTD_HTTP_REQ_HEADER_DONE,      /*!< received headers completely */
    RESTD_HTTP_REQ_DONE,             /*!< received body completely. no more data expected */

    RESTD_HTTP_ERROR, /*!< unrecoverable error found. */
};

/*----------------------------------------------------------------------------*\
|                             PUBLIC FUNCTIONS                                 |
\*----------------------------------------------------------------------------*/
extern restd_http_t *http_new(struct evbuffer *out);
extern void http_free_cb(restd_conn_t *conn, void *userdata);
extern int restd_http_handler(short event, restd_conn_t *conn, void *userdata);

extern enum restd_http_request_status_e restd_http_get_status(restd_conn_t *conn);
extern struct evbuffer *restd_http_get_inbuf(restd_conn_t *conn);
extern struct evbuffer *restd_http_get_outbuf(restd_conn_t *conn);

extern const char *restd_http_get_request_header(restd_conn_t *conn, const char *name);
extern off_t restd_http_get_content_length(restd_conn_t *conn);
extern size_t restd_http_get_content_length_stored(restd_conn_t *conn);
extern void *restd_http_get_content(restd_conn_t *conn, size_t maxsize, size_t *storedsize);
extern int restd_http_is_keepalive_request(restd_conn_t *conn);

extern int restd_http_set_response_header(restd_conn_t *conn, const char *name, const char *value);
extern const char *restd_http_get_response_header(restd_conn_t *conn, const char *name);
extern int restd_http_set_response_code(restd_conn_t *conn, int code, const char *reason);
extern int restd_http_set_response_content(restd_conn_t *conn, const char *contenttype, off_t size);

extern size_t restd_http_response(restd_conn_t *conn, int code, const char *contenttype, const void *data, off_t size);
extern size_t restd_http_send_header(restd_conn_t *conn);
extern size_t restd_http_send_data(restd_conn_t *conn, const void *data, size_t size);
extern size_t restd_http_send_chunk(restd_conn_t *conn, const void *data, size_t size);

extern const char *restd_http_get_reason(int code);

/*---------------------------------------------------------------------------*\
|                            DATA STRUCTURES                                  |
\*---------------------------------------------------------------------------*/
struct restd_http_s
{
    // HTTP Request
    struct
    {
        enum restd_http_request_status_e status; /*!< request status. */
        struct evbuffer *inbuf;                  /*!< input data buffer. */

        // request line - available on REQ_REQUESTLINE_DONE.
        char *method;  /*!< request method ex) GET */
        char *uri;     /*!< url+query ex) /data%20path?query=the%20value */
        char *httpver; /*!< version ex) HTTP/1.1 */
        char *path;    /*!< decoded path ex) /data path */
        char *query;   /*!< query string ex) query=the%20value */

        // request header - available on REQ_HEADER_DONE.
        qlisttbl_t *headers; /*!< parsed request header entries */
        char *host;          /*!< host ex) www.domain.com or www.domain.com:8080 */
        char *domain;        /*!< domain name ex) www.domain.com (no port number) */
        off_t contentlength; /*!< value of Content-Length header.*/
        size_t bodyin;       /*!< bytes moved to in-buff */
    } request;

    // HTTP Response
    struct
    {
        struct evbuffer *outbuf; /*!< output data buffer. */
        bool frozen_header;      /*!< indicator whether we sent header out or not */

        // response headers
        int code;            /*!< response status-code */
        char *reason;        /*!< reason-phrase */
        qlisttbl_t *headers; /*!< response header entries */
        off_t contentlength; /*!< content length in response */
        size_t bodyout;      /*!< bytes added to out-buffer */
    } response;
};

#endif /* _RESTD_HTTP_HANDLER_H */