#pragma once
#include <stdint.h>
#include <stddef.h>
#include "stellar/session.h"
#include "stellar/http.h"
#include "llhttp.h"
#include "uthash/utarray.h"
#include "http_decoder_decompress.h"

#ifdef __cplusplus
extern "C"
{
#endif
#define HTTP_HEADER_FIELD_RESERVE_NUM (16)

#define HTTP_HEADER_FIELD_NAME_HOST "Host"
#define HTTP_HEADER_FIELD_NAME_USER_AGENT "User-Agent"
#define HTTP_HEADER_FIELD_NAME_REFERER "Referer"
#define HTTP_HEADER_FIELD_NAME_COOKIE "Cookie"
#define HTTP_HEADER_FIELD_NAME_SET_COOKIE "Set-Cookie"
#define HTTP_HEADER_FIELD_NAME_CONTENT_TYPE "Content-Type"
#define HTTP_HEADER_FIELD_NAME_CONTENT_LENGTH "Content-Length"
#define HTTP_HEADER_FIELD_NAME_CONTENT_ENCODING "Content-Encoding"
#define HTTP_HEADER_FIELD_NAME_TRANSFER_ENCODING "Transfer-Encoding"

    enum http_event
    {
        __HTTP_EVENT_RESERVED = 0,
        HTTP_EVENT_REQ_INIT = 1 << 1,
        HTTP_EVENT_REQ_LINE = 1 << 2,
        HTTP_EVENT_REQ_HDR = 1 << 3,
        HTTP_EVENT_REQ_HDR_END = 1 << 4,
        HTTP_EVENT_REQ_BODY_BEGIN = 1 << 5,
        HTTP_EVENT_REQ_BODY_DATA = 1 << 6,
        HTTP_EVENT_REQ_BODY_END = 1 << 7,
        HTTP_EVENT_REQ_END = 1 << 8,

        HTTP_EVENT_RES_INIT = 1 << 9,
        HTTP_EVENT_RES_LINE = 1 << 10,
        HTTP_EVENT_RES_HDR = 1 << 11,
        HTTP_EVENT_RES_HDR_END = 1 << 12,
        HTTP_EVENT_RES_BODY_BEGIN = 1 << 13,
        HTTP_EVENT_RES_BODY_DATA = 1 << 14,
        HTTP_EVENT_RES_BODY_END = 1 << 15,
        HTTP_EVENT_RES_END = 1 << 16,
    };

    struct http_body
    {
        char *body;
        size_t body_sz;
        size_t offset; // accumulated
        int is_finished;
    };

#ifndef hstring
#include <bits/types/struct_iovec.h>
    typedef struct iovec hstring;
#endif

    struct http_half_data
    {
        enum flow_type flow_dir;
        uint32_t transaction_seq; // seq of this half flow, is last http_lalf->transaction_num value
        union
        {
            struct http_request_line req_line;
            struct http_status_line status_line;
        };

        /* headers */
        struct http_buffer *cached_header_buffer; // maybe null
        hstring joint_url;                        // malloc, need be free
        enum http_content_encoding content_encoding_type;
        int transfer_encoding_is_chunked; // -1: not set, 0: false, 1: true
        UT_array *ut_filed_array;         // inner struct, need to transform to header->field_array
        struct http_header header;

        /* body */
        struct http_body raw_body;
        struct http_content_decompress *decompress;
        struct http_body decompress_body;
    };

    struct http_half_parser
    {
        llhttp_t llhttp_parser;
        llhttp_settings_t settings;
        struct http_half *half_ref; // used in llhttp callback context to get flow
    };

    enum http_stage
    {
        HTTP_STAGE_INIT = 0,
        HTTP_STAGE_PENDING = 1, /* body without Content-Length, no Chunk-Encoding */
        HTTP_STAGE_HEADER_PARTIAL = 2,
        HTTP_STAGE_BODY = 3,
    };

    struct http_stage_shaper
    {
        enum http_stage stage;
        char *data;
        size_t data_len;
        long long remain_content_length;
        const char *headers_start;         // the first header field name
        const char *headers_end;           // the last char of \r\n\r\n
        struct http_buffer *headers_cache; /* ownership move to struct http_decoder_half_data when headers completed */
    };

    struct http_half_buffer
    {
        int is_malloc; // need free
        int ref_count; // +1 when push a new message
        char *buffer;
        size_t buffer_size;
    };

    enum http_half_llhttp_stage_type
    {
        LLHTTP_STAGE_MESSAGE_BEGIN = 0,
        LLHTTP_STAGE_URI,
        LLHTTP_STAGE_METHOD,
        LLHTTP_STAGE_STATUS,
        LLHTTP_STAGE_VERSION,
        LLHTTP_STAGE_HEADER_FIELD,
        LLHTTP_STAGE_HEADER_FIELD_COMPLETE,
        LLHTTP_STAGE_HEADER_VALUE,
        LLHTTP_STAGE_HEADER_VALUE_COMPLETE,
        LLHTTP_STAGE_HEADERS_COMPLETE,
        LLHTTP_STAGE_BODY,
        LLHTTP_STAGE_MESSAGE_COMPLETE,
        __LLHTTP_STAGE_MAX,
    };

    struct http_half_llhttp_stage
    {
        const char *first_header_name_ptr;
        const char *last_header_value_complete_ptr; /* at + length + 4 \r\n\r\n) */
        const char *last_headers_complete_ptr;
        enum http_half_llhttp_stage_type llhttp_last_stage;
        uint8_t llhttp_cb_count[__LLHTTP_STAGE_MAX];
    };

    struct http_half
    {
        struct session *sess_ref;
        struct http *http_env_ref;

        uint32_t transaction_num; // accumulated of all flows in this session
        enum http_event event;
        // struct http_stage_shaper shaper;

        struct http_half_parser parser;
        struct http_half_data *flow_data; // malloc when every transaction start, ownership move to message when message completed

        struct http_buffer *cached_header_buffer;
        struct http_half_llhttp_stage half_stage;
    };
    void http_half_free(struct http_half *half);
    void http_half_data_free(struct http_half_data *half_data);
    void http_flow_parser_init(struct http_half_parser *flow_parser, enum llhttp_type type);
    void http_flow_body_decompress(struct http_half_data *flow_data, const char *zipdata, size_t zipdatalen);
    void http_event_handler(struct http_half *half, enum http_event event, struct http *httpd_env);
    int http_flow_stage_shaping(struct http_half *half, const char *newdata, size_t newdata_len);
    int http_half_flow_process(struct http_half *half, const char *newdata, size_t newdata_len);
    int http_get_header_field_count(struct http_half_data *flow_data);
    void http_flow_append_header_filed(struct http_half_data *flow_data, const char *at, size_t length);
    void http_flow_append_header_value(struct http_half_data *flow_data, const char *at, size_t length);
#ifdef __cplusplus
}
#endif