HttpParser.h

// Copyright (c) Stefano Cristiano
// SPDX-License-Identifier: MIT
#pragma once
#include "../Foundation/Result.h"
#include "../Foundation/Span.h"
 
namespace SC
{
struct SC_COMPILER_EXPORT HttpParser;
} // namespace SC
 
 
struct SC::HttpParser
{
    enum class Method
    {
        HttpGET,  
        HttpPUT,  
        HttpPOST, 
    };
    Method method = Method::HttpGET; 
 
    size_t   tokenStart    = 0; 
    size_t   tokenLength   = 0; 
    uint32_t statusCode    = 0; 
    uint64_t contentLength = 0; 
 
    enum class State
    {
        Parsing,  
        Result,   
        Finished, 
    };
 
    enum class Result
    {
        Method,       
        Url,          
        Version,      
        HeaderName,   
        HeaderValue,  
        HeadersEnd,   
        StatusCode,   
        StatusString, 
        Body          
    };
 
    Result result = Result::HeadersEnd; 
    State  state  = State::Parsing;     
 
    enum class Type
    {
        Request, 
        Response 
    };
    Type type = Type::Request; 
 
    [[nodiscard]] SC::Result parse(Span<const char> data, size_t& readBytes, Span<const char>& parsedData);
 
    enum class HeaderType
    {
        ContentLength = 0 
    };
 
    [[nodiscard]] bool matchesHeader(HeaderType headerName) const;
 
  private:
    size_t globalStart           = 0;
    size_t globalLength          = 0;
    int    topLevelCoroutine     = 0;
    int    nestedParserCoroutine = 0;
    bool   parsedContentLength   = false;
    size_t matchIndex            = 0;
 
    static constexpr size_t numMatches = 1;
 
    size_t   matchingHeader[numMatches]      = {0};
    bool     matchingHeaderValid[numMatches] = {false};
    uint64_t number                          = 0;
 
    [[nodiscard]] bool parseHeaderName(char currentChar);
    [[nodiscard]] bool parseHeaderValue(char currentChar);
    [[nodiscard]] bool parseStatusCode(char currentChar);
    [[nodiscard]] bool parseNumberValue(char currentChar);
    [[nodiscard]] bool parseHeadersEnd(char currentChar);
    [[nodiscard]] bool parseMethod(char currentChar);
    [[nodiscard]] bool parseUrl(char currentChar);
 
    template <bool spaces>
    [[nodiscard]] bool parseVersion(char currentChar);
 
    template <bool (HttpParser::*Func)(char), Result currentResult>
    [[nodiscard]] SC::Result process(Span<const char>& data, size_t& readBytes, Span<const char>& parsedData);
};