/*
 * various utility functions for use within FFmpeg
 * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg 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.
 *
 * FFmpeg 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.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <stdint.h>
#include <time.h>

#include "config.h"

#include "libavutil/avassert.h"
#include "libavutil/avstring.h"
#include "libavutil/bprint.h"
#include "libavutil/dict.h"
#include "libavutil/internal.h"
#include "libavutil/mem.h"
#include "libavutil/opt.h"
#include "libavutil/parseutils.h"
#include "libavutil/time.h"
#include "libavutil/time_internal.h"

#include "libavcodec/internal.h"

#include "avformat.h"
#include "avio_internal.h"
#include "internal.h"
#if CONFIG_NETWORK
#include "network.h"
#endif
#include "os_support.h"
#include "urldecode.h"

/**
 * @file
 * various utility functions for use within FFmpeg
 */

/* an arbitrarily chosen "sane" max packet size -- 50M */
#define SANE_CHUNK_SIZE (50000000)

/* Read the data in sane-sized chunks and append to pkt.
 * Return the number of bytes read or an error. */
static int append_packet_chunked(AVIOContext *s, AVPacket *pkt, int size)
{
    int orig_size      = pkt->size;
    int ret;

    do {
        int prev_size = pkt->size;
        int read_size;

        /* When the caller requests a lot of data, limit it to the amount
         * left in file or SANE_CHUNK_SIZE when it is not known. */
        read_size = size;
        if (read_size > SANE_CHUNK_SIZE/10) {
            read_size = ffio_limit(s, read_size);
            // If filesize/maxsize is unknown, limit to SANE_CHUNK_SIZE
            if (ffiocontext(s)->maxsize < 0)
                read_size = FFMIN(read_size, SANE_CHUNK_SIZE);
        }

        ret = av_grow_packet(pkt, read_size);
        if (ret < 0)
            break;

        ret = avio_read(s, pkt->data + prev_size, read_size);
        if (ret != read_size) {
            av_shrink_packet(pkt, prev_size + FFMAX(ret, 0));
            break;
        }

        size -= read_size;
    } while (size > 0);
    if (size > 0)
        pkt->flags |= AV_PKT_FLAG_CORRUPT;

    if (!pkt->size)
        av_packet_unref(pkt);
    return pkt->size > orig_size ? pkt->size - orig_size : ret;
}

int av_get_packet(AVIOContext *s, AVPacket *pkt, int size)
{
#if FF_API_INIT_PACKET
FF_DISABLE_DEPRECATION_WARNINGS
    av_init_packet(pkt);
    pkt->data = NULL;
    pkt->size = 0;
FF_ENABLE_DEPRECATION_WARNINGS
#else
    av_packet_unref(pkt);
#endif
    pkt->pos  = avio_tell(s);

    return append_packet_chunked(s, pkt, size);
}

int av_append_packet(AVIOContext *s, AVPacket *pkt, int size)
{
    if (!pkt->size)
        return av_get_packet(s, pkt, size);
    return append_packet_chunked(s, pkt, size);
}

int av_filename_number_test(const char *filename)
{
    AVBPrint bp;

    if (!filename)
        return 0;
    av_bprint_init(&bp, 0, AV_BPRINT_SIZE_COUNT_ONLY);
    return (ff_bprint_get_frame_filename(&bp, filename, 1, AV_FRAME_FILENAME_FLAGS_IGNORE_TRUNCATION) >= 0);
}

/**********************************************************/

unsigned int ff_codec_get_tag(const AVCodecTag *tags, enum AVCodecID id)
{
    while (tags->id != AV_CODEC_ID_NONE) {
        if (tags->id == id)
            return tags->tag;
        tags++;
    }
    return 0;
}

enum AVCodecID ff_codec_get_id(const AVCodecTag *tags, unsigned int tag)
{
    for (int i = 0; tags[i].id != AV_CODEC_ID_NONE; i++)
        if (tag == tags[i].tag)
            return tags[i].id;
    for (int i = 0; tags[i].id != AV_CODEC_ID_NONE; i++)
        if (ff_toupper4(tag) == ff_toupper4(tags[i].tag))
            return tags[i].id;
    return AV_CODEC_ID_NONE;
}

enum AVCodecID ff_get_pcm_codec_id(int bps, int flt, int be, int sflags)
{
    if (bps <= 0 || bps > 64)
        return AV_CODEC_ID_NONE;

    if (flt) {
        switch (bps) {
        case 32:
            return be ? AV_CODEC_ID_PCM_F32BE : AV_CODEC_ID_PCM_F32LE;
        case 64:
            return be ? AV_CODEC_ID_PCM_F64BE : AV_CODEC_ID_PCM_F64LE;
        default:
            return AV_CODEC_ID_NONE;
        }
    } else {
        bps  += 7;
        bps >>= 3;
        if (sflags & (1 << (bps - 1))) {
            switch (bps) {
            case 1:
                return AV_CODEC_ID_PCM_S8;
            case 2:
                return be ? AV_CODEC_ID_PCM_S16BE : AV_CODEC_ID_PCM_S16LE;
            case 3:
                return be ? AV_CODEC_ID_PCM_S24BE : AV_CODEC_ID_PCM_S24LE;
            case 4:
                return be ? AV_CODEC_ID_PCM_S32BE : AV_CODEC_ID_PCM_S32LE;
            case 8:
                return be ? AV_CODEC_ID_PCM_S64BE : AV_CODEC_ID_PCM_S64LE;
            default:
                return AV_CODEC_ID_NONE;
            }
        } else {
            switch (bps) {
            case 1:
                return AV_CODEC_ID_PCM_U8;
            case 2:
                return be ? AV_CODEC_ID_PCM_U16BE : AV_CODEC_ID_PCM_U16LE;
            case 3:
                return be ? AV_CODEC_ID_PCM_U24BE : AV_CODEC_ID_PCM_U24LE;
            case 4:
                return be ? AV_CODEC_ID_PCM_U32BE : AV_CODEC_ID_PCM_U32LE;
            default:
                return AV_CODEC_ID_NONE;
            }
        }
    }
}

unsigned int av_codec_get_tag(const AVCodecTag *const *tags, enum AVCodecID id)
{
    unsigned int tag;
    if (!av_codec_get_tag2(tags, id, &tag))
        return 0;
    return tag;
}

int av_codec_get_tag2(const AVCodecTag * const *tags, enum AVCodecID id,
                      unsigned int *tag)
{
    for (int i = 0; tags && tags[i]; i++) {
        const AVCodecTag *codec_tags = tags[i];
        while (codec_tags->id != AV_CODEC_ID_NONE) {
            if (codec_tags->id == id) {
                *tag = codec_tags->tag;
                return 1;
            }
            codec_tags++;
        }
    }
    return 0;
}

enum AVCodecID av_codec_get_id(const AVCodecTag *const *tags, unsigned int tag)
{
    for (int i = 0; tags && tags[i]; i++) {
        enum AVCodecID id = ff_codec_get_id(tags[i], tag);
        if (id != AV_CODEC_ID_NONE)
            return id;
    }
    return AV_CODEC_ID_NONE;
}

int ff_alloc_extradata(AVCodecParameters *par, int size)
{
    av_freep(&par->extradata);
    par->extradata_size = 0;

    if (size < 0 || size >= INT32_MAX - AV_INPUT_BUFFER_PADDING_SIZE)
        return AVERROR(EINVAL);

    par->extradata = av_malloc(size + AV_INPUT_BUFFER_PADDING_SIZE);
    if (!par->extradata)
        return AVERROR(ENOMEM);

    memset(par->extradata + size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
    par->extradata_size = size;

    return 0;
}

/*******************************************************/

uint64_t ff_ntp_time(void)
{
    return (av_gettime() / 1000) * 1000 + NTP_OFFSET_US;
}

uint64_t ff_get_formatted_ntp_time(uint64_t ntp_time_us)
{
    uint64_t ntp_ts, frac_part, sec;
    uint32_t usec;

    //current ntp time in seconds and microseconds
    sec = ntp_time_us / 1000000;
    usec = ntp_time_us % 1000000;

    //encoding in ntp timestamp format
    frac_part = usec * 0xFFFFFFFFULL;
    frac_part /= 1000000;

    if (sec > 0xFFFFFFFFULL)
        av_log(NULL, AV_LOG_WARNING, "NTP time format roll over detected\n");

    ntp_ts = sec << 32;
    ntp_ts |= frac_part;

    return ntp_ts;
}

uint64_t ff_parse_ntp_time(uint64_t ntp_ts)
{
    uint64_t sec = ntp_ts >> 32;
    uint64_t frac_part = ntp_ts & 0xFFFFFFFFULL;
    uint64_t usec = (frac_part * 1000000) / 0xFFFFFFFFULL;

    return (sec * 1000000) + usec;
}

int ff_bprint_get_frame_filename(struct AVBPrint *buf, const char *path, int64_t number, int flags)
{
    const char *p;
    char c;
    int nd, percentd_found;

    p = path;
    percentd_found = 0;
    for (;;) {
        c = *p++;
        if (c == '\0')
            break;
        if (c == '%') {
            do {
                nd = 0;
                while (av_isdigit(*p)) {
                    if (nd >= INT_MAX / 10 - 255)
                        goto fail;
                    nd = nd * 10 + *p++ - '0';
                }
                c = *p++;
            } while (av_isdigit(c));

            switch (c) {
            case '%':
                goto addchar;
            case 'd':
                if (!(flags & AV_FRAME_FILENAME_FLAGS_MULTIPLE) && percentd_found)
                    goto fail;
                percentd_found = 1;
                if (number < 0)
                    nd += 1;
                av_bprintf(buf, "%0*" PRId64, nd, number);
                break;
            default:
                goto fail;
            }
        } else {
addchar:
            av_bprint_chars(buf, c, 1);
        }
    }
    if (!percentd_found)
        goto fail;
    if (!(flags & AV_FRAME_FILENAME_FLAGS_IGNORE_TRUNCATION) && !av_bprint_is_complete(buf))
        return AVERROR(ENOMEM);
    return 0;
fail:
    return AVERROR(EINVAL);
}

static int get_frame_filename(char *buf, int buf_size, const char *path, int64_t number, int flags)
{
    AVBPrint bp;
    av_bprint_init_for_buffer(&bp, buf, buf_size);
    return ff_bprint_get_frame_filename(&bp, path, number, flags) < 0 ? -1 : 0;
}

int av_get_frame_filename2(char *buf, int buf_size, const char *path, int number, int flags)
{
    return get_frame_filename(buf, buf_size, path, number, flags);
}

int av_get_frame_filename(char *buf, int buf_size, const char *path, int number)
{
    return get_frame_filename(buf, buf_size, path, number, 0);
}

void av_url_split(char *proto, int proto_size,
                  char *authorization, int authorization_size,
                  char *hostname, int hostname_size,
                  int *port_ptr, char *path, int path_size, const char *url)
{
    const char *p, *ls, *at, *at2, *col, *brk;

    if (port_ptr)
        *port_ptr = -1;
    if (proto_size > 0)
        proto[0] = 0;
    if (authorization_size > 0)
        authorization[0] = 0;
    if (hostname_size > 0)
        hostname[0] = 0;
    if (path_size > 0)
        path[0] = 0;

    /* parse protocol */
    if ((p = strchr(url, ':'))) {
        av_strlcpy(proto, url, FFMIN(proto_size, p + 1 - url));
        p++; /* skip ':' */
        if (*p == '/')
            p++;
        if (*p == '/')
            p++;
    } else {
        /* no protocol means plain filename */
        av_strlcpy(path, url, path_size);
        return;
    }

    /* separate path from hostname */
    ls = p + strcspn(p, "/?#");
    av_strlcpy(path, ls, path_size);

    /* the rest is hostname, use that to parse auth/port */
    if (ls != p) {
        /* authorization (user[:pass]@hostname) */
        at2 = p;
        while ((at = strchr(p, '@')) && at < ls) {
            av_strlcpy(authorization, at2,
                       FFMIN(authorization_size, at + 1 - at2));
            p = at + 1; /* skip '@' */
        }

        if (*p == '[' && (brk = strchr(p, ']')) && brk < ls) {
            /* [host]:port */
            av_strlcpy(hostname, p + 1,
                       FFMIN(hostname_size, brk - p));
            if (brk[1] == ':' && port_ptr)
                *port_ptr = atoi(brk + 2);
        } else if ((col = strchr(p, ':')) && col < ls) {
            av_strlcpy(hostname, p,
                       FFMIN(col + 1 - p, hostname_size));
            if (port_ptr)
                *port_ptr = atoi(col + 1);
        } else
            av_strlcpy(hostname, p,
                       FFMIN(ls + 1 - p, hostname_size));
    }
}

int ff_mkdir_p(const char *path)
{
    int ret = 0;
    char *temp = av_strdup(path);
    char *pos = temp;
    char tmp_ch = '\0';

    if (!path || !temp) {
        return -1;
    }

    if (!av_strncasecmp(temp, "/", 1) || !av_strncasecmp(temp, "\\", 1)) {
        pos++;
    } else if (!av_strncasecmp(temp, "./", 2) || !av_strncasecmp(temp, ".\\", 2)) {
        pos += 2;
    }

    for ( ; *pos != '\0'; ++pos) {
        if (*pos == '/' || *pos == '\\') {
            tmp_ch = *pos;
            *pos = '\0';
            ret = mkdir(temp, 0755);
            if (ret < 0 && errno != EEXIST) {
                int err = errno;
                av_free(temp);
                errno = err;
                return ret;
            }
            *pos = tmp_ch;
        }
    }

    if ((*(pos - 1) != '/') && (*(pos - 1) != '\\')) {
        ret = mkdir(temp, 0755);
    }

    av_free(temp);
    return ret;
}

char *ff_data_to_hex(char *buff, const uint8_t *src, int s, int lowercase)
{
    static const char hex_table_uc[16] = { '0', '1', '2', '3',
                                           '4', '5', '6', '7',
                                           '8', '9', 'A', 'B',
                                           'C', 'D', 'E', 'F' };
    static const char hex_table_lc[16] = { '0', '1', '2', '3',
                                           '4', '5', '6', '7',
                                           '8', '9', 'a', 'b',
                                           'c', 'd', 'e', 'f' };
    const char *hex_table = lowercase ? hex_table_lc : hex_table_uc;

    av_assume(s >= 0);
    for (unsigned i = 0; i < s; i++) {
        buff[i * 2]     = hex_table[src[i] >> 4];
        buff[i * 2 + 1] = hex_table[src[i] & 0xF];
    }
    buff[2U * s] = '\0';

    return buff;
}

int ff_hex_to_data(uint8_t *data, const char *p)
{
    int c, len, v;

    len = 0;
    v   = 1;
    for (;;) {
        p += strspn(p, SPACE_CHARS);
        if (*p == '\0')
            break;
        c = av_toupper((unsigned char) *p++);
        if (c >= '0' && c <= '9')
            c = c - '0';
        else if (c >= 'A' && c <= 'F')
            c = c - 'A' + 10;
        else
            break;
        v = (v << 4) | c;
        if (v & 0x100) {
            if (data)
                data[len] = v;
            len++;
            v = 1;
        }
    }
    return len;
}

void ff_parse_key_value(const char *str, ff_parse_key_val_cb callback_get_buf,
                        void *context)
{
    const char *ptr = str;

    /* Parse key=value pairs. */
    for (;;) {
        const char *key;
        char *dest = NULL, *dest_end;
        int key_len, dest_len = 0;

        /* Skip whitespace and potential commas. */
        while (*ptr && (av_isspace(*ptr) || *ptr == ','))
            ptr++;
        if (!*ptr)
            break;

        key = ptr;

        if (!(ptr = strchr(key, '=')))
            break;
        ptr++;
        key_len = ptr - key;

        callback_get_buf(context, key, key_len, &dest, &dest_len);
        dest_end = dest ? dest + dest_len - 1 : NULL;

        if (*ptr == '\"') {
            ptr++;
            while (*ptr && *ptr != '\"') {
                if (*ptr == '\\') {
                    if (!ptr[1])
                        break;
                    if (dest && dest < dest_end)
                        *dest++ = ptr[1];
                    ptr += 2;
                } else {
                    if (dest && dest < dest_end)
                        *dest++ = *ptr;
                    ptr++;
                }
            }
            if (*ptr == '\"')
                ptr++;
        } else {
            for (; *ptr && !(av_isspace(*ptr) || *ptr == ','); ptr++)
                if (dest && dest < dest_end)
                    *dest++ = *ptr;
        }
        if (dest)
            *dest = 0;
    }
}

int avformat_network_init(void)
{
#if CONFIG_NETWORK
    int ret;
    if ((ret = ff_network_init()) < 0)
        return ret;
    if ((ret = ff_tls_init()) < 0)
        return ret;
#endif
    return 0;
}

int avformat_network_deinit(void)
{
#if CONFIG_NETWORK
    ff_network_close();
    ff_tls_deinit();
#endif
    return 0;
}

int ff_is_http_proto(const char *filename) {
    const char *proto = avio_find_protocol_name(filename);
    return proto ? (!av_strcasecmp(proto, "http") || !av_strcasecmp(proto, "https")) : 0;
}

int ff_bprint_to_codecpar_extradata(AVCodecParameters *par, struct AVBPrint *buf)
{
    int ret;
    char *str;

    ret = av_bprint_finalize(buf, &str);
    if (ret < 0)
        return ret;
    if (!av_bprint_is_complete(buf)) {
        av_free(str);
        return AVERROR(ENOMEM);
    }

    par->extradata = str;
    /* Note: the string is NUL terminated (so extradata can be read as a
     * string), but the ending character is not accounted in the size (in
     * binary formats you are likely not supposed to mux that character). When
     * extradata is copied, it is also padded with AV_INPUT_BUFFER_PADDING_SIZE
     * zeros. */
    par->extradata_size = buf->len;
    return 0;
}

int ff_dict_set_timestamp(AVDictionary **dict, const char *key, int64_t timestamp)
{
    int microsecs = timestamp % 1000000;
    time_t seconds = timestamp / 1000000 - (microsecs < 0);
    struct tm *ptm, tmbuf;
    ptm = gmtime_r(&seconds, &tmbuf);
    if (ptm) {
        char buf[32];
        if (!strftime(buf, sizeof(buf), "%Y-%m-%dT%H:%M:%S", ptm))
            return AVERROR_EXTERNAL;
        av_strlcatf(buf, sizeof(buf), ".%06dZ", microsecs + (microsecs < 0) * 1000000);
        return av_dict_set(dict, key, buf, 0);
    } else {
        return AVERROR_EXTERNAL;
    }
}

static const AVOption* find_opt(void *obj, const char *name, size_t len)
{
    char decoded_name[128];

    if (ff_urldecode_len(decoded_name, sizeof(decoded_name), name, len, 1) < 0)
        return NULL;

    return av_opt_find(obj, decoded_name, NULL, 0, 0);
}

int ff_parse_opts_from_query_string(void *obj, const char *str, int allow_unknown)
{
    const AVOption *opt;
    char optval[512];
    int ret;

    if (*str == '?')
        str++;
    while (*str) {
        size_t len = strcspn(str, "=&");
        opt = find_opt(obj, str, len);
        if (!opt) {
            if (!allow_unknown) {
                av_log(obj, AV_LOG_ERROR, "Query string option '%.*s' does not exist\n", (int)len, str);
                return AVERROR_OPTION_NOT_FOUND;
            }
            av_log(obj, AV_LOG_VERBOSE, "Ignoring unknown query string option '%.*s'\n", (int)len, str);
        }
        str += len;
        if (!opt) {
            len = strcspn(str, "&");
            str += len;
        } else if (*str == '&' || *str == '\0') {
            /* Check for bool options without value, e.g. "?verify".
             * Unfortunately "listen" is a tri-state INT for some protocols so
             * we also have to allow that for backward compatibility. */
            if (opt->type != AV_OPT_TYPE_BOOL && strcmp(opt->name, "listen")) {
                av_log(obj, AV_LOG_ERROR, "Non-bool query string option '%s' has no value\n", opt->name);
                return AVERROR(EINVAL);
            }
            ret = av_opt_set_int(obj, opt->name, 1, 0);
            if (ret < 0)
                return ret;
        } else {
            av_assert2(*str == '=');
            str++;
            len = strcspn(str, "&");
            if (ff_urldecode_len(optval, sizeof(optval), str, len, 1) < 0) {
                av_log(obj, AV_LOG_ERROR, "Query string option '%s' value is too long\n", opt->name);
                return AVERROR(EINVAL);
            }
            ret = av_opt_set(obj, opt->name, optval, 0);
            if (ret < 0)
                return ret;
            str += len;
        }
        if (*str)
            str++;
    }
    return 0;
}

void *ff_bprint_finalize_as_fam(struct AVBPrint *bp, const void *struct_ptr, size_t fam_offset)
{
    if (!av_bprint_is_complete(bp)) {
        av_bprint_finalize(bp, NULL);
        return NULL;
    }

    uint8_t *p = av_malloc(fam_offset + bp->len);
    if (!p) {
        av_bprint_finalize(bp, NULL);
        return NULL;
    }
    memcpy(p, struct_ptr, fam_offset);
    memcpy(p + fam_offset, bp->str, bp->len);
    av_bprint_finalize(bp, NULL);

    return p;
}
