/**
 *  Copyright (C) 2011-2012  Juho Vähä-Herttua
 *
 *  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.
 */

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

#include "http_request.h"
#include "http_parser.h"

struct http_request_s {
    http_parser parser;
    http_parser_settings parser_settings;

    const char *method;
    char *url;

    char **headers;
    int headers_size;
    int headers_index;

    char *data;
    int datalen;

    int complete;
};

static int
on_url(http_parser *parser, const char *at, size_t length)
{
    http_request_t *request = parser->data;
    int urllen = request->url ? strlen(request->url) : 0;

    request->url = realloc(request->url, urllen+length+1);
    assert(request->url);

    request->url[urllen] = '\0';
    strncat(request->url, at, length);
    return 0;
}

static int
on_header_field(http_parser *parser, const char *at, size_t length)
{
    http_request_t *request = parser->data;

    /* Check if our index is a value */
    if (request->headers_index%2 == 1) {
        request->headers_index++;
    }

    /* Allocate space for new field-value pair */
    if (request->headers_index == request->headers_size) {
        request->headers_size += 2;
        request->headers = realloc(request->headers,
                                   request->headers_size*sizeof(char*));
        assert(request->headers);
        request->headers[request->headers_index] = NULL;
        request->headers[request->headers_index+1] = NULL;
    }

    /* Allocate space in the current header string */
    if (request->headers[request->headers_index] == NULL) {
        request->headers[request->headers_index] = calloc(1, length+1);
    } else {
        request->headers[request->headers_index] = realloc(
                request->headers[request->headers_index],
                strlen(request->headers[request->headers_index])+length+1
        );
    }
    assert(request->headers[request->headers_index]);

    strncat(request->headers[request->headers_index], at, length);
    return 0;
}

static int
on_header_value(http_parser *parser, const char *at, size_t length)
{
    http_request_t *request = parser->data;

    /* Check if our index is a field */
    if (request->headers_index%2 == 0) {
        request->headers_index++;
    }

    /* Allocate space in the current header string */
    if (request->headers[request->headers_index] == NULL) {
        request->headers[request->headers_index] = calloc(1, length+1);
    } else {
        request->headers[request->headers_index] = realloc(
                request->headers[request->headers_index],
                strlen(request->headers[request->headers_index])+length+1
        );
    }
    assert(request->headers[request->headers_index]);

    strncat(request->headers[request->headers_index], at, length);
    return 0;
}

static int
on_body(http_parser *parser, const char *at, size_t length)
{
    http_request_t *request = parser->data;

    request->data = realloc(request->data, request->datalen+length);
    assert(request->data);

    memcpy(request->data+request->datalen, at, length);
    request->datalen += length;
    return 0;
}

static int
on_message_complete(http_parser *parser)
{
    http_request_t *request = parser->data;

    request->method = http_method_str(request->parser.method);
    request->complete = 1;
    return 0;
}

http_request_t *
http_request_init(void)
{
    http_request_t *request;

    request = calloc(1, sizeof(http_request_t));
    if (!request) {
        return NULL;
    }
    http_parser_init(&request->parser, HTTP_REQUEST);
    request->parser.data = request;

    request->parser_settings.on_url = &on_url;
    request->parser_settings.on_header_field = &on_header_field;
    request->parser_settings.on_header_value = &on_header_value;
    request->parser_settings.on_body = &on_body;
    request->parser_settings.on_message_complete = &on_message_complete;

    return request;
}

void
http_request_destroy(http_request_t *request)
{
    int i;

    if (request) {
        free(request->url);
        for (i=0; i<request->headers_size; i++) {
            free(request->headers[i]);
        }
        free(request->headers);
        free(request->data);
        free(request);
    }
}

int
http_request_add_data(http_request_t *request, const char *data, int datalen)
{
    int ret;

    assert(request);

    ret = http_parser_execute(&request->parser,
                              &request->parser_settings,
                              data, datalen);
    return ret;
}

int
http_request_is_complete(http_request_t *request)
{
    assert(request);
    return request->complete;
}

int
http_request_has_error(http_request_t *request)
{
    assert(request);
    return (HTTP_PARSER_ERRNO(&request->parser) != HPE_OK);
}

const char *
http_request_get_error_name(http_request_t *request)
{
    assert(request);
    return http_errno_name(HTTP_PARSER_ERRNO(&request->parser));
}

const char *
http_request_get_error_description(http_request_t *request)
{
    assert(request);
    return http_errno_description(HTTP_PARSER_ERRNO(&request->parser));
}

const char *
http_request_get_method(http_request_t *request)
{
    assert(request);
    return request->method;
}

const char *
http_request_get_url(http_request_t *request)
{
    assert(request);
    return request->url;
}

const char *
http_request_get_header(http_request_t *request, const char *name)
{
    int i;

    assert(request);

    for (i=0; i<request->headers_size; i+=2) {
        if (!strcmp(request->headers[i], name)) {
            return request->headers[i+1];
        }
    }
    return NULL;
}

const char *
http_request_get_data(http_request_t *request, int *datalen)
{
    assert(request);

    if (datalen) {
        *datalen = request->datalen;
    }
    return request->data;
}
