/*
 * FreeRTOS V202212.00
 * Copyright (C) 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * https://www.FreeRTOS.org
 * https://github.com/FreeRTOS
 *
 */

/**
 *!
 *! The protocols implemented in this file are intended to be demo quality only,
 *! and not for production devices.
 *!
 */

/* Standard includes. */
#include <stdio.h>
#include <stdlib.h>

/* FreeRTOS includes. */
#include "FreeRTOS.h"
#include "task.h"

/* FreeRTOS+TCP includes. */
#include "FreeRTOS_IP.h"
#include "FreeRTOS_Sockets.h"

/* FreeRTOS Protocol includes. */
#include "FreeRTOS_HTTP_commands.h"
#include "FreeRTOS_TCP_server.h"
#include "FreeRTOS_server_private.h"

/* Remove the whole file if HTTP is not supported. */
#if ( ipconfigUSE_HTTP == 1 )

/* FreeRTOS+FAT includes. */
    #include "ff_stdio.h"

    #ifndef HTTP_SERVER_BACKLOG
        #define HTTP_SERVER_BACKLOG    ( 12 )
    #endif

    #ifndef USE_HTML_CHUNKS
        #define USE_HTML_CHUNKS    ( 0 )
    #endif

    #if !defined( ARRAY_SIZE )
        #define ARRAY_SIZE( x )    ( BaseType_t ) ( sizeof( x ) / sizeof( x )[ 0 ] )
    #endif

/* Some defines to make the code more readbale */
    #define pcCOMMAND_BUFFER                      pxClient->pxParent->pcCommandBuffer
    #define pcNEW_DIR                             pxClient->pxParent->pcNewDir
    #define pcFILE_BUFFER                         pxClient->pxParent->pcFileBuffer

    #ifndef ipconfigHTTP_REQUEST_CHARACTER
        #define ipconfigHTTP_REQUEST_CHARACTER    '?'
    #endif

/*_RB_ Need comment block, although fairly self evident. */
    static void prvFileClose( HTTPClient_t * pxClient );
    static BaseType_t prvProcessCmd( HTTPClient_t * pxClient,
                                     BaseType_t xIndex );
    static const char * pcGetContentsType( const char * apFname );
    static BaseType_t prvOpenURL( HTTPClient_t * pxClient );
    static BaseType_t prvSendFile( HTTPClient_t * pxClient );
    static BaseType_t prvSendReply( HTTPClient_t * pxClient,
                                    BaseType_t xCode );

    static const char pcEmptyString[ 1 ] = { '\0' };

    typedef struct xTYPE_COUPLE
    {
        const char * pcExtension;
        const char * pcType;
    } TypeCouple_t;

    static TypeCouple_t pxTypeCouples[] =
    {
        { "html", "text/html"              },
        { "css",  "text/css"               },
        { "js",   "text/javascript"        },
        { "png",  "image/png"              },
        { "jpg",  "image/jpeg"             },
        { "gif",  "image/gif"              },
        { "txt",  "text/plain"             },
        { "mp3",  "audio/mpeg3"            },
        { "wav",  "audio/wav"              },
        { "flac", "audio/ogg"              },
        { "pdf",  "application/pdf"        },
        { "ttf",  "application/x-font-ttf" },
        { "ttc",  "application/x-font-ttf" }
    };

    void vHTTPClientDelete( TCPClient_t * pxTCPClient )
    {
        HTTPClient_t * pxClient = ( HTTPClient_t * ) pxTCPClient;

        /* This HTTP client stops, close / release all resources. */
        if( pxClient->xSocket != FREERTOS_NO_SOCKET )
        {
            FreeRTOS_FD_CLR( pxClient->xSocket, pxClient->pxParent->xSocketSet, eSELECT_ALL );
            FreeRTOS_closesocket( pxClient->xSocket );
            pxClient->xSocket = FREERTOS_NO_SOCKET;
        }

        prvFileClose( pxClient );
    }
/*-----------------------------------------------------------*/

    static void prvFileClose( HTTPClient_t * pxClient )
    {
        if( pxClient->pxFileHandle != NULL )
        {
            FreeRTOS_printf( ( "Closing file: %s\n", pxClient->pcCurrentFilename ) );
            ff_fclose( pxClient->pxFileHandle );
            pxClient->pxFileHandle = NULL;
        }
    }
/*-----------------------------------------------------------*/

    static BaseType_t prvSendReply( HTTPClient_t * pxClient,
                                    BaseType_t xCode )
    {
        struct xTCP_SERVER * pxParent = pxClient->pxParent;
        BaseType_t xRc;

        /* A normal command reply on the main socket (port 21). */
        char * pcBuffer = pxParent->pcFileBuffer;

        xRc = snprintf( pcBuffer, sizeof( pxParent->pcFileBuffer ),
                        "HTTP/1.1 %d %s\r\n"
                        #if USE_HTML_CHUNKS
                            "Transfer-Encoding: chunked\r\n"
                        #endif
                        "Content-Type: %s\r\n"
                        "Connection: keep-alive\r\n"
                        "%s\r\n",
                        ( int ) xCode,
                        webCodename( xCode ),
                        pxParent->pcContentsType[ 0 ] ? pxParent->pcContentsType : "text/html",
                        pxParent->pcExtraContents );

        pxParent->pcContentsType[ 0 ] = '\0';
        pxParent->pcExtraContents[ 0 ] = '\0';

        xRc = FreeRTOS_send( pxClient->xSocket, ( const void * ) pcBuffer, xRc, 0 );
        pxClient->bits.bReplySent = pdTRUE_UNSIGNED;

        return xRc;
    }
/*-----------------------------------------------------------*/

    static BaseType_t prvSendFile( HTTPClient_t * pxClient )
    {
        size_t uxSpace;
        size_t uxCount;
        BaseType_t xRc = 0;

        if( pxClient->bits.bReplySent == pdFALSE_UNSIGNED )
        {
            pxClient->bits.bReplySent = pdTRUE_UNSIGNED;

            strcpy( pxClient->pxParent->pcContentsType, pcGetContentsType( pxClient->pcCurrentFilename ) );
            snprintf( pxClient->pxParent->pcExtraContents, sizeof( pxClient->pxParent->pcExtraContents ),
                      "Content-Length: %d\r\n", ( int ) pxClient->uxBytesLeft );

            /* "Requested file action OK". */
            xRc = prvSendReply( pxClient, WEB_REPLY_OK );
        }

        if( xRc >= 0 )
        {
            do
            {
                uxSpace = FreeRTOS_tx_space( pxClient->xSocket );

                if( pxClient->uxBytesLeft < uxSpace )
                {
                    uxCount = pxClient->uxBytesLeft;
                }
                else
                {
                    uxCount = uxSpace;
                }

                if( uxCount > 0u )
                {
                    if( uxCount > sizeof( pxClient->pxParent->pcFileBuffer ) )
                    {
                        uxCount = sizeof( pxClient->pxParent->pcFileBuffer );
                    }

                    ff_fread( pxClient->pxParent->pcFileBuffer, 1, uxCount, pxClient->pxFileHandle );
                    pxClient->uxBytesLeft -= uxCount;

                    xRc = FreeRTOS_send( pxClient->xSocket, pxClient->pxParent->pcFileBuffer, uxCount, 0 );

                    if( xRc < 0 )
                    {
                        break;
                    }
                }
            } while( uxCount > 0u );
        }

        if( pxClient->uxBytesLeft == 0u )
        {
            /* Writing is ready, no need for further 'eSELECT_WRITE' events. */
            FreeRTOS_FD_CLR( pxClient->xSocket, pxClient->pxParent->xSocketSet, eSELECT_WRITE );
            prvFileClose( pxClient );
        }
        else
        {
            /* Wake up the TCP task as soon as this socket may be written to. */
            FreeRTOS_FD_SET( pxClient->xSocket, pxClient->pxParent->xSocketSet, eSELECT_WRITE );
        }

        return xRc;
    }
/*-----------------------------------------------------------*/

    static BaseType_t prvOpenURL( HTTPClient_t * pxClient )
    {
        BaseType_t xRc;
        char pcSlash[ 2 ];

        pxClient->bits.ulFlags = 0;

        #if ( ipconfigHTTP_HAS_HANDLE_REQUEST_HOOK != 0 )
        {
            if( strchr( pxClient->pcUrlData, ipconfigHTTP_REQUEST_CHARACTER ) != NULL )
            {
                size_t xResult;

                xResult = uxApplicationHTTPHandleRequestHook( pxClient->pcUrlData, pxClient->pcCurrentFilename, sizeof( pxClient->pcCurrentFilename ) );

                if( xResult > 0 )
                {
                    strcpy( pxClient->pxParent->pcContentsType, "text/html" );
                    snprintf( pxClient->pxParent->pcExtraContents, sizeof( pxClient->pxParent->pcExtraContents ),
                              "Content-Length: %d\r\n", ( int ) xResult );
                    xRc = prvSendReply( pxClient, WEB_REPLY_OK ); /* "Requested file action OK" */

                    if( xRc > 0 )
                    {
                        xRc = FreeRTOS_send( pxClient->xSocket, pxClient->pcCurrentFilename, xResult, 0 );
                    }

                    /* Although against the coding standard of FreeRTOS, a return is
                     * done here  to simplify this conditional code. */
                    return xRc;
                }
            }
        }
        #endif /* ipconfigHTTP_HAS_HANDLE_REQUEST_HOOK */

        if( pxClient->pcUrlData[ 0 ] != '/' )
        {
            /* Insert a slash before the file name. */
            pcSlash[ 0 ] = '/';
            pcSlash[ 1 ] = '\0';
        }
        else
        {
            /* The browser provided a starting '/' already. */
            pcSlash[ 0 ] = '\0';
        }

        snprintf( pxClient->pcCurrentFilename, sizeof( pxClient->pcCurrentFilename ), "%s%s%s",
                  pxClient->pcRootDir,
                  pcSlash,
                  pxClient->pcUrlData );

        pxClient->pxFileHandle = ff_fopen( pxClient->pcCurrentFilename, "rb" );

        FreeRTOS_printf( ( "Open file '%s': %s\n", pxClient->pcCurrentFilename,
                           pxClient->pxFileHandle != NULL ? "Ok" : strerror( stdioGET_ERRNO() ) ) );

        if( pxClient->pxFileHandle == NULL )
        {
            /* "404 File not found". */
            xRc = prvSendReply( pxClient, WEB_NOT_FOUND );
        }
        else
        {
            pxClient->uxBytesLeft = ( size_t ) pxClient->pxFileHandle->ulFileSize;
            xRc = prvSendFile( pxClient );
        }

        return xRc;
    }
/*-----------------------------------------------------------*/

    static BaseType_t prvProcessCmd( HTTPClient_t * pxClient,
                                     BaseType_t xIndex )
    {
        BaseType_t xResult = 0;

        /* A new command has been received. Process it. */
        switch( xIndex )
        {
            case ECMD_GET:
                xResult = prvOpenURL( pxClient );
                break;

            case ECMD_HEAD:
            case ECMD_POST:
            case ECMD_PUT:
            case ECMD_DELETE:
            case ECMD_TRACE:
            case ECMD_OPTIONS:
            case ECMD_CONNECT:
            case ECMD_PATCH:
            case ECMD_UNK:
                FreeRTOS_printf( ( "prvProcessCmd: Not implemented: %s\n",
                                   xWebCommands[ xIndex ].pcCommandName ) );
                break;
        }

        return xResult;
    }
/*-----------------------------------------------------------*/

    BaseType_t xHTTPClientWork( TCPClient_t * pxTCPClient )
    {
        BaseType_t xRc;
        HTTPClient_t * pxClient = ( HTTPClient_t * ) pxTCPClient;

        if( pxClient->pxFileHandle != NULL )
        {
            prvSendFile( pxClient );
        }

        xRc = FreeRTOS_recv( pxClient->xSocket, ( void * ) pcCOMMAND_BUFFER, sizeof( pcCOMMAND_BUFFER ), 0 );

        if( xRc > 0 )
        {
            BaseType_t xIndex;
            const char * pcEndOfCmd;
            const struct xWEB_COMMAND * curCmd;
            char * pcBuffer = pcCOMMAND_BUFFER;

            if( xRc < ( BaseType_t ) sizeof( pcCOMMAND_BUFFER ) )
            {
                pcBuffer[ xRc ] = '\0';
            }

            while( xRc && ( pcBuffer[ xRc - 1 ] == 13 || pcBuffer[ xRc - 1 ] == 10 ) )
            {
                pcBuffer[ --xRc ] = '\0';
            }

            pcEndOfCmd = pcBuffer + xRc;

            curCmd = xWebCommands;

            /* Pointing to "/index.html HTTP/1.1". */
            pxClient->pcUrlData = pcBuffer;

            /* Pointing to "HTTP/1.1". */
            pxClient->pcRestData = pcEmptyString;

            /* Last entry is "ECMD_UNK". */
            for( xIndex = 0; xIndex < WEB_CMD_COUNT - 1; xIndex++, curCmd++ )
            {
                BaseType_t xLength;

                xLength = curCmd->xCommandLength;

                if( ( xRc >= xLength ) && ( memcmp( curCmd->pcCommandName, pcBuffer, xLength ) == 0 ) )
                {
                    char * pcLastPtr;

                    pxClient->pcUrlData += xLength + 1;

                    for( pcLastPtr = ( char * ) pxClient->pcUrlData; pcLastPtr < pcEndOfCmd; pcLastPtr++ )
                    {
                        char ch = *pcLastPtr;

                        if( ( ch == '\0' ) || ( strchr( "\n\r \t", ch ) != NULL ) )
                        {
                            *pcLastPtr = '\0';
                            pxClient->pcRestData = pcLastPtr + 1;
                            break;
                        }
                    }

                    break;
                }
            }

            if( xIndex < ( WEB_CMD_COUNT - 1 ) )
            {
                xRc = prvProcessCmd( pxClient, xIndex );
            }
        }
        else if( xRc < 0 )
        {
            /* The connection will be closed and the client will be deleted. */
            FreeRTOS_printf( ( "xHTTPClientWork: rc = %ld\n", xRc ) );
        }

        return xRc;
    }
/*-----------------------------------------------------------*/

    static const char * pcGetContentsType( const char * apFname )
    {
        const char * slash = NULL;
        const char * dot = NULL;
        const char * ptr;
        const char * pcResult = "text/html";
        BaseType_t x;

        for( ptr = apFname; *ptr; ptr++ )
        {
            if( *ptr == '.' )
            {
                dot = ptr;
            }

            if( *ptr == '/' )
            {
                slash = ptr;
            }
        }

        if( dot > slash )
        {
            dot++;

            for( x = 0; x < ARRAY_SIZE( pxTypeCouples ); x++ )
            {
                if( strcasecmp( dot, pxTypeCouples[ x ].pcExtension ) == 0 )
                {
                    pcResult = pxTypeCouples[ x ].pcType;
                    break;
                }
            }
        }

        return pcResult;
    }

#endif /* ipconfigUSE_HTTP */