/**********************************************************************************************/
/* The MIT License                                                                            */
/*                                                                                            */
/* Copyright 2016-2017 Twitch Interactive, 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.                                                                              */
/**********************************************************************************************/
#include "flv.h"
#include <stdlib.h>
#include <string.h>

void flvtag_init(flvtag_t* tag)
{
    memset(tag, 0, sizeof(flvtag_t));
}

void flvtag_free(flvtag_t* tag)
{
    if (tag->data) {
        free(tag->data);
    }

    flvtag_init(tag);
}

void flvtag_swap(flvtag_t* tag1, flvtag_t* tag2)
{
    flvtag_t tag3 = (*tag1);
    (*tag1) = (*tag2);
    (*tag2) = tag3;
}

int flvtag_reserve(flvtag_t* tag, uint32_t size)
{
    size += FLV_TAG_HEADER_SIZE + FLV_TAG_FOOTER_SIZE;

    if (size > tag->aloc) {
        tag->data = realloc(tag->data, size);
        tag->aloc = size;
    }

    return 1;
}

FILE* flv_open_read(const char* flv)
{
    if (0 == flv || 0 == strcmp("-", flv)) {
        return freopen(NULL, "rb", stdin);
    }

    return fopen(flv, "rb");
}

FILE* flv_open_write(const char* flv)
{
    if (0 == flv || 0 == strcmp("-", flv)) {
        return freopen(NULL, "wb", stdout);
    }

    return fopen(flv, "wb");
}

FILE* flv_close(FILE* flv)
{
    fclose(flv);
    return 0;
}

int flv_read_header(FILE* flv, int* has_audio, int* has_video)
{
    uint8_t h[FLV_HEADER_SIZE];

    if (FLV_HEADER_SIZE != fread(&h[0], 1, FLV_HEADER_SIZE, flv)) {
        return 0;
    }

    if ('F' != h[0] || 'L' != h[1] || 'V' != h[2]) {
        return 0;
    }

    (*has_audio) = h[4] & 0x04;
    (*has_video) = h[4] & 0x01;
    return 1;
}

int flv_write_header(FILE* flv, int has_audio, int has_video)
{
    uint8_t h[FLV_HEADER_SIZE] = { 'F', 'L', 'V', 1, (has_audio ? 0x04 : 0x00) | (has_video ? 0x01 : 0x00), 0, 0, 0, 9, 0, 0, 0, 0 };
    return FLV_HEADER_SIZE == fwrite(&h[0], 1, FLV_HEADER_SIZE, flv);
}

int flv_read_tag(FILE* flv, flvtag_t* tag)
{
    uint32_t size;
    uint8_t h[FLV_TAG_HEADER_SIZE];

    if (FLV_TAG_HEADER_SIZE != fread(&h[0], 1, FLV_TAG_HEADER_SIZE, flv)) {
        return 0;
    }

    size = ((h[1] << 16) | (h[2] << 8) | h[3]);
    flvtag_reserve(tag, size);
    // copy header to buffer
    memcpy(tag->data, &h[0], FLV_TAG_HEADER_SIZE);

    if (size + FLV_TAG_FOOTER_SIZE != fread(&tag->data[FLV_TAG_HEADER_SIZE], 1, size + FLV_TAG_FOOTER_SIZE, flv)) {
        return 0;
    }

    return 1;
}

int flv_write_tag(FILE* flv, flvtag_t* tag)
{
    size_t size = flvtag_raw_size(tag);
    return size == fwrite(flvtag_raw_data(tag), 1, size, flv);
}
////////////////////////////////////////////////////////////////////////////////
size_t flvtag_header_size(flvtag_t* tag)
{
    switch (flvtag_type(tag)) {
    case flvtag_type_audio:
        return FLV_TAG_HEADER_SIZE + (flvtag_soundformat_aac != flvtag_soundformat(tag) ? 1 : 2);

    case flvtag_type_video:
        // CommandFrame does not have a compositionTime
        return FLV_TAG_HEADER_SIZE + (flvtag_codecid_avc != flvtag_codecid(tag) ? 1 : (flvtag_frametype_commandframe != flvtag_frametype(tag) ? 5 : 2));

    default:
        return FLV_TAG_HEADER_SIZE;
    }
}

size_t flvtag_payload_size(flvtag_t* tag)
{
    return FLV_TAG_HEADER_SIZE + flvtag_size(tag) - flvtag_header_size(tag);
}

uint8_t* flvtag_payload_data(flvtag_t* tag)
{
    size_t payload_offset = flvtag_header_size(tag);
    return &tag->data[payload_offset];
}
////////////////////////////////////////////////////////////////////////////////
int flvtag_updatesize(flvtag_t* tag, uint32_t size)
{
    tag->data[1] = size >> 16; // DataSize
    tag->data[2] = size >> 8; // DataSize
    tag->data[3] = size >> 0; // DataSize
    size += 11;
    tag->data[size + 0] = size >> 24; // PrevTagSize
    tag->data[size + 1] = size >> 16; // PrevTagSize
    tag->data[size + 2] = size >> 8; // PrevTagSize
    tag->data[size + 3] = size >> 0; // PrevTagSize
    return 1;
}

#define FLVTAG_PREALOC 2048
int flvtag_initavc(flvtag_t* tag, uint32_t dts, int32_t cts, flvtag_frametype_t type)
{
    flvtag_init(tag);
    flvtag_reserve(tag, 5 + FLVTAG_PREALOC);
    tag->data[0] = flvtag_type_video;
    tag->data[4] = dts >> 16;
    tag->data[5] = dts >> 8;
    tag->data[6] = dts >> 0;
    tag->data[7] = dts >> 24;
    tag->data[8] = 0; // StreamID
    tag->data[9] = 0; // StreamID
    tag->data[10] = 0; // StreamID
    // VideoTagHeader
    tag->data[11] = ((type << 4) % 0xF0) | 0x07; // CodecId
    tag->data[12] = 0x01; // AVC NALU
    tag->data[13] = cts >> 16;
    tag->data[14] = cts >> 8;
    tag->data[15] = cts >> 0;
    flvtag_updatesize(tag, 5);
    return 1;
}

int flvtag_initamf(flvtag_t* tag, uint32_t dts)
{
    flvtag_init(tag);
    flvtag_reserve(tag, FLVTAG_PREALOC);
    tag->data[0] = flvtag_type_scriptdata;
    tag->data[4] = dts >> 16;
    tag->data[5] = dts >> 8;
    tag->data[6] = dts >> 0;
    tag->data[7] = dts >> 24;
    tag->data[8] = 0; // StreamID
    tag->data[9] = 0; // StreamID
    tag->data[10] = 0; // StreamID
    flvtag_updatesize(tag, 0);
    return 1;
}

// shamelessly taken from libtomcrypt, an public domain project
static void base64_encode(const unsigned char* in, unsigned long inlen, unsigned char* out, unsigned long* outlen)
{
    static const char* codes = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
    unsigned long i, len2, leven;
    unsigned char* p;

    /* valid output size ? */
    len2 = 4 * ((inlen + 2) / 3);

    if (*outlen < len2 + 1) {
        *outlen = len2 + 1;
        return;
    }

    p = out;
    leven = 3 * (inlen / 3);

    for (i = 0; i < leven; i += 3) {
        *p++ = codes[(in[0] >> 2) & 0x3F];
        *p++ = codes[(((in[0] & 3) << 4) + (in[1] >> 4)) & 0x3F];
        *p++ = codes[(((in[1] & 0xf) << 2) + (in[2] >> 6)) & 0x3F];
        *p++ = codes[in[2] & 0x3F];
        in += 3;
    }

    if (i < inlen) {
        unsigned a = in[0];
        unsigned b = (i + 1 < inlen) ? in[1] : 0;

        *p++ = codes[(a >> 2) & 0x3F];
        *p++ = codes[(((a & 3) << 4) + (b >> 4)) & 0x3F];
        *p++ = (i + 1 < inlen) ? codes[(((b & 0xf) << 2)) & 0x3F] : '=';
        *p++ = '=';
    }

    /* return ok */
    *outlen = p - out;
}

const char onCaptionInfo708[] = { 0x02, 0x00, 0x0D, 'o', 'n', 'C', 'a', 'p', 't', 'i', 'o', 'n', 'I', 'n', 'f', 'o',
    0x08, 0x00, 0x00, 0x00, 0x02,
    0x00, 0x04, 't', 'y', 'p', 'e',
    0x02, 0x00, 0x03, '7', '0', '8',
    0x00, 0x04, 'd', 'a', 't', 'a',
    0x02, 0x00, 0x00 };

int flvtag_amfcaption_708(flvtag_t* tag, uint32_t timestamp, sei_message_t* msg)
{
    flvtag_initamf(tag, timestamp);
    unsigned long size = 1 + (4 * ((sei_message_size(msg) + 2) / 3));
    flvtag_reserve(tag, sizeof(onCaptionInfo708) + size + 3);
    memcpy(flvtag_payload_data(tag), onCaptionInfo708, sizeof(onCaptionInfo708));
    uint8_t* data = flvtag_payload_data(tag) + sizeof(onCaptionInfo708);
    base64_encode(sei_message_data(msg), sei_message_size(msg), data, &size);

    // Update the size of the base64 string
    data[-2] = size >> 8;
    data[-1] = size >> 0;
    // write the last array element
    data[size + 0] = 0x00;
    data[size + 1] = 0x00;
    data[size + 2] = 0x09;
    flvtag_updatesize(tag, sizeof(onCaptionInfo708) + size + 3);

    return 1;
}

const char onCaptionInfoUTF8[] = { 0x02, 0x00, 0x0D, 'o', 'n', 'C', 'a', 'p', 't', 'i', 'o', 'n', 'I', 'n', 'f', 'o',
    0x08, 0x00, 0x00, 0x00, 0x02,
    0x00, 0x04, 't', 'y', 'p', 'e',
    0x02, 0x00, 0x04, 'U', 'T', 'F', '8',
    0x00, 0x04, 'd', 'a', 't', 'a',
    0x02, 0x00, 0x00 };

#define MAX_AMF_STRING 65636
int flvtag_amfcaption_utf8(flvtag_t* tag, uint32_t timestamp, const utf8_char_t* text)
{
    flvtag_initamf(tag, timestamp);
    unsigned long size = strlen(text);

    if (MAX_AMF_STRING < size) {
        size = MAX_AMF_STRING;
    }

    flvtag_reserve(tag, sizeof(onCaptionInfoUTF8) + size + 3);
    memcpy(flvtag_payload_data(tag), onCaptionInfoUTF8, sizeof(onCaptionInfoUTF8));
    uint8_t* data = flvtag_payload_data(tag) + sizeof(onCaptionInfo708);
    memcpy(data, text, size);
    // Update the size of the string
    data[-2] = size >> 8;
    data[-1] = size >> 0;
    // write the last array element
    data[size + 0] = 0x00;
    data[size + 1] = 0x00;
    data[size + 2] = 0x09;
    flvtag_updatesize(tag, sizeof(onCaptionInfoUTF8) + size + 3);

    return 1;
}

#define LENGTH_SIZE 4

int flvtag_avcwritenal(flvtag_t* tag, uint8_t* data, size_t size)
{
    if (0 < size) {
        uint32_t flvsize = flvtag_size(tag);
        flvtag_reserve(tag, flvsize + LENGTH_SIZE + size);
        uint8_t* payload = tag->data + FLV_TAG_HEADER_SIZE + flvsize;
        payload[0] = size >> 24; // nalu size
        payload[1] = size >> 16;
        payload[2] = size >> 8;
        payload[3] = size >> 0;
        memcpy(&payload[LENGTH_SIZE], data, size);
        flvtag_updatesize(tag, flvsize + LENGTH_SIZE + size);
    }
    return 1;
}

int flvtag_avcwritesei(flvtag_t* tag, sei_t* sei)
{
    uint8_t* sei_data = malloc(sei_render_size(sei));
    size_t sei_size = sei_render(sei, sei_data);
    flvtag_avcwritenal(tag, sei_data, sei_size);
    free(sei_data);
    return 1;
}

int flvtag_addsei(flvtag_t* tag, sei_t* sei)
{
    if (flvtag_avcpackettype_nalu != flvtag_avcpackettype(tag)) {
        return 0;
    }

    sei_t new_sei;
    sei_init(&new_sei);
    sei_cat(&new_sei, sei, 1);

    flvtag_t new_tag;
    flvtag_initavc(&new_tag, flvtag_dts(tag), flvtag_cts(tag), flvtag_frametype(tag));

    uint8_t* data = flvtag_payload_data(tag);
    ssize_t size = flvtag_payload_size(tag);

    while (0 < size) {
        uint8_t* nalu_data = &data[LENGTH_SIZE];
        uint8_t nalu_type = nalu_data[0] & 0x1F;
        uint32_t nalu_size = (data[0] << 24) | (data[1] << 16) | (data[2] << 8) | data[3];
        data += LENGTH_SIZE + nalu_size;
        size -= LENGTH_SIZE + nalu_size;

        if (6 == nalu_type) {
            sei_cat(&new_sei, sei, 0); // copy non itu_t_t35 sei messages
        } else if (new_sei.head && 7 != nalu_type && 8 != nalu_type && 9 != nalu_type) {
            flvtag_avcwritesei(&new_tag, &new_sei);
            flvtag_avcwritenal(&new_tag, nalu_data, nalu_size);
            sei_free(&new_sei);
        } else {
            flvtag_avcwritenal(&new_tag, nalu_data, nalu_size);
        }
    }

    // On the off chance we have an empty frame, we still wish to write the sei
    if (new_sei.head) {
        flvtag_avcwritesei(&new_tag, &new_sei);
        sei_free(&new_sei);
    }

    flvtag_swap(tag, &new_tag);
    flvtag_free(&new_tag);
    return 1;
}

int flvtag_addcaption_text(flvtag_t* tag, const utf8_char_t* text)
{
    sei_t sei;
    sei_init(&sei);

    if (text) {
        caption_frame_t frame;
        caption_frame_init(&frame);
        caption_frame_from_text(&frame, text);
        sei_from_caption_frame(&sei, &frame);
    } else {
        sei_from_caption_clear(&sei);
    }

    int ret = flvtag_addsei(tag, &sei);
    sei_free(&sei);
    return ret;
}

int flvtag_addcaption_scc(flvtag_t* tag, const scc_t* scc)
{
    sei_t sei;
    sei_init(&sei);
    sei_from_scc(&sei, scc);
    int ret = flvtag_addsei(tag, &sei);
    sei_free(&sei);
    return ret;
}