/*

 * Copyright (c) 2006 Rene Scharfe

 */

#define USE_THE_REPOSITORY_VARIABLE

#include "git-compat-util.h"

#include "config.h"

#include "archive.h"

#include "gettext.h"

#include "git-zlib.h"

#include "hex.h"

#include "streaming.h"

#include "utf8.h"

#include "object-store-ll.h"

#include "strbuf.h"

#include "userdiff.h"

#include "write-or-die.h"

#include "xdiff-interface.h"

#include "date.h"

static int zip_date;

static int zip_time;

/* We only care about the "buf" part here. */

static struct strbuf zip_dir;

static uintmax_t zip_offset;

static uint64_t zip_dir_entries;

static unsigned int max_creator_version;

#define ZIP_STREAM  (1 <<  3)

#define ZIP_UTF8  (1 << 11)

enum zip_method {

  ZIP_METHOD_STORE = 0,

  ZIP_METHOD_DEFLATE = 8

};

struct zip_local_header {

  unsigned char magic[4];

  unsigned char version[2];

  unsigned char flags[2];

  unsigned char compression_method[2];

  unsigned char mtime[2];

  unsigned char mdate[2];

  unsigned char crc32[4];

  unsigned char compressed_size[4];

  unsigned char size[4];

  unsigned char filename_length[2];

  unsigned char extra_length[2];

  unsigned char _end[1];

};

struct zip_data_desc {

  unsigned char magic[4];

  unsigned char crc32[4];

  unsigned char compressed_size[4];

  unsigned char size[4];

  unsigned char _end[1];

};

struct zip64_data_desc {

  unsigned char magic[4];

  unsigned char crc32[4];

  unsigned char compressed_size[8];

  unsigned char size[8];

  unsigned char _end[1];

};

struct zip_dir_trailer {

  unsigned char magic[4];

  unsigned char disk[2];

  unsigned char directory_start_disk[2];

  unsigned char entries_on_this_disk[2];

  unsigned char entries[2];

  unsigned char size[4];

  unsigned char offset[4];

  unsigned char comment_length[2];

  unsigned char _end[1];

};

struct zip_extra_mtime {

  unsigned char magic[2];

  unsigned char extra_size[2];

  unsigned char flags[1];

  unsigned char mtime[4];

  unsigned char _end[1];

};

struct zip64_extra {

  unsigned char magic[2];

  unsigned char extra_size[2];

  unsigned char size[8];

  unsigned char compressed_size[8];

  unsigned char _end[1];

};

struct zip64_dir_trailer {

  unsigned char magic[4];

  unsigned char record_size[8];

  unsigned char creator_version[2];

  unsigned char version[2];

  unsigned char disk[4];

  unsigned char directory_start_disk[4];

  unsigned char entries_on_this_disk[8];

  unsigned char entries[8];

  unsigned char size[8];

  unsigned char offset[8];

  unsigned char _end[1];

};

struct zip64_dir_trailer_locator {

  unsigned char magic[4];

  unsigned char disk[4];

  unsigned char offset[8];

  unsigned char number_of_disks[4];

  unsigned char _end[1];

};

/*

 * On ARM, padding is added at the end of the struct, so a simple

 * sizeof(struct ...) reports two bytes more than the payload size

 * we're interested in.

 */

#define ZIP_LOCAL_HEADER_SIZE offsetof(struct zip_local_header, _end)

#define ZIP_DATA_DESC_SIZE  offsetof(struct zip_data_desc, _end)

#define ZIP64_DATA_DESC_SIZE  offsetof(struct zip64_data_desc, _end)

#define ZIP_DIR_HEADER_SIZE offsetof(struct zip_dir_header, _end)

#define ZIP_DIR_TRAILER_SIZE  offsetof(struct zip_dir_trailer, _end)

#define ZIP_EXTRA_MTIME_SIZE  offsetof(struct zip_extra_mtime, _end)

#define ZIP_EXTRA_MTIME_PAYLOAD_SIZE \

  (ZIP_EXTRA_MTIME_SIZE - offsetof(struct zip_extra_mtime, flags))

#define ZIP64_EXTRA_SIZE  offsetof(struct zip64_extra, _end)

#define ZIP64_EXTRA_PAYLOAD_SIZE \

  (ZIP64_EXTRA_SIZE - offsetof(struct zip64_extra, size))

#define ZIP64_DIR_TRAILER_SIZE  offsetof(struct zip64_dir_trailer, _end)

#define ZIP64_DIR_TRAILER_RECORD_SIZE \

  (ZIP64_DIR_TRAILER_SIZE - \

   offsetof(struct zip64_dir_trailer, creator_version))

#define ZIP64_DIR_TRAILER_LOCATOR_SIZE \

  offsetof(struct zip64_dir_trailer_locator, _end)

static void copy_le16(unsigned char *dest, unsigned int n)

{

  dest[0] = 0xff & n;

  dest[1] = 0xff & (n >> 010);

}

static void copy_le32(unsigned char *dest, unsigned int n)

{

  dest[0] = 0xff & n;

  dest[1] = 0xff & (n >> 010);

  dest[2] = 0xff & (n >> 020);

  dest[3] = 0xff & (n >> 030);

}

static void copy_le64(unsigned char *dest, uint64_t n)

{

  dest[0] = 0xff & n;

  dest[1] = 0xff & (n >> 010);

  dest[2] = 0xff & (n >> 020);

  dest[3] = 0xff & (n >> 030);

  dest[4] = 0xff & (n >> 040);

  dest[5] = 0xff & (n >> 050);

  dest[6] = 0xff & (n >> 060);

  dest[7] = 0xff & (n >> 070);

}

static uint64_t clamp_max(uint64_t n, uint64_t max, int *clamped)

{

  if (n <= max)

    return n;

  *clamped = 1;

  return max;

}

static void copy_le16_clamp(unsigned char *dest, uint64_t n, int *clamped)

{

  copy_le16(dest, clamp_max(n, 0xffff, clamped));

}

static void copy_le32_clamp(unsigned char *dest, uint64_t n, int *clamped)

{

  copy_le32(dest, clamp_max(n, 0xffffffff, clamped));

}

static int strbuf_add_le(struct strbuf *sb, size_t size, uintmax_t n)

{

  while (size-- > 0) {

    strbuf_addch(sb, n & 0xff);

    n >>= 8;

  }

  return -!!n;

}

static uint32_t clamp32(uintmax_t n)

{

  const uintmax_t max = 0xffffffff;

  return (n < max) ? n : max;

}

static void *zlib_deflate_raw(void *data, unsigned long size,

            int compression_level,

            unsigned long *compressed_size)

{

  git_zstream stream;

  unsigned long maxsize;

  void *buffer;

  int result;

  git_deflate_init_raw(&stream, compression_level);

  maxsize = git_deflate_bound(&stream, size);

  buffer = xmalloc(maxsize);

  stream.next_in = data;

  stream.avail_in = size;

  stream.next_out = buffer;

  stream.avail_out = maxsize;

  do {

    result = git_deflate(&stream, Z_FINISH);

  } while (result == Z_OK);

  if (result != Z_STREAM_END) {

    free(buffer);

    return NULL;

  }

  git_deflate_end(&stream);

  *compressed_size = stream.total_out;

  return buffer;

}

static void write_zip_data_desc(unsigned long size,

        unsigned long compressed_size,

        unsigned long crc)

{

  if (size >= 0xffffffff || compressed_size >= 0xffffffff) {

    struct zip64_data_desc trailer;

    copy_le32(trailer.magic, 0x08074b50);

    copy_le32(trailer.crc32, crc);

    copy_le64(trailer.compressed_size, compressed_size);

    copy_le64(trailer.size, size);

    write_or_die(1, &trailer, ZIP64_DATA_DESC_SIZE);

    zip_offset += ZIP64_DATA_DESC_SIZE;

  } else {

    struct zip_data_desc trailer;

    copy_le32(trailer.magic, 0x08074b50);

    copy_le32(trailer.crc32, crc);

    copy_le32(trailer.compressed_size, compressed_size);

    copy_le32(trailer.size, size);

    write_or_die(1, &trailer, ZIP_DATA_DESC_SIZE);

    zip_offset += ZIP_DATA_DESC_SIZE;

  }

}

static void set_zip_header_data_desc(struct zip_local_header *header,

             unsigned long size,

             unsigned long compressed_size,

             unsigned long crc)

{

  copy_le32(header->crc32, crc);

  copy_le32(header->compressed_size, compressed_size);

  copy_le32(header->size, size);

}

static int has_only_ascii(const char *s)

{

  for (;;) {

    int c = *s++;

    if (c == '\0')

      return 1;

    if (!isascii(c))

      return 0;

  }

}

static int entry_is_binary(struct index_state *istate, const char *path,

         const void *buffer, size_t size)

{

  struct userdiff_driver *driver = userdiff_find_by_path(istate, path);

  if (!driver)

    driver = userdiff_find_by_name("default");

  if (driver->binary != -1)

    return driver->binary;

  return buffer_is_binary(buffer, size);

}

#define STREAM_BUFFER_SIZE (1024 * 16)

static int write_zip_entry(struct archiver_args *args,

         const struct object_id *oid,

         const char *path, size_t pathlen,

         unsigned int mode,

         void *buffer, unsigned long size)

{

  struct zip_local_header header;

  uintmax_t offset = zip_offset;

  struct zip_extra_mtime extra;

  struct zip64_extra extra64;

  size_t header_extra_size = ZIP_EXTRA_MTIME_SIZE;

  int need_zip64_extra = 0;

  unsigned long attr2;

  unsigned long compressed_size;

  unsigned long crc;

  enum zip_method method;

  unsigned char *out;

  void *deflated = NULL;

  struct git_istream *stream = NULL;

  unsigned long flags = 0;

  int is_binary = -1;

  const char *path_without_prefix = path + args->baselen;

  unsigned int creator_version = 0;

  unsigned int version_needed = 10;

  size_t zip_dir_extra_size = ZIP_EXTRA_MTIME_SIZE;

  size_t zip64_dir_extra_payload_size = 0;

  crc = crc32(0, NULL, 0);

  if (!has_only_ascii(path)) {

    if (is_utf8(path))

      flags |= ZIP_UTF8;

    else

      warning(_("path is not valid UTF-8: %s"), path);

  }

  if (pathlen > 0xffff) {

    return error(_("path too long (%d chars, SHA1: %s): %s"),

        (int)pathlen, oid_to_hex(oid), path);

  }

  if (S_ISDIR(mode) || S_ISGITLINK(mode)) {

    method = ZIP_METHOD_STORE;

    attr2 = 16;

    out = NULL;

    compressed_size = 0;

  } else if (S_ISREG(mode) || S_ISLNK(mode)) {

    method = ZIP_METHOD_STORE;

    attr2 = S_ISLNK(mode) ? ((mode | 0777) << 16) :

      (mode & 0111) ? ((mode) << 16) : 0;

    if (S_ISLNK(mode) || (mode & 0111))

      creator_version = 0x0317;

    if (S_ISREG(mode) && args->compression_level != 0 && size > 0)

      method = ZIP_METHOD_DEFLATE;

    if (!buffer) {

      enum object_type type;

      stream = open_istream(args->repo, oid, &type, &size,

                NULL);

      if (!stream)

        return error(_("cannot stream blob %s"),

               oid_to_hex(oid));

      flags |= ZIP_STREAM;

      out = NULL;

    } else {

      crc = crc32(crc, buffer, size);

      is_binary = entry_is_binary(args->repo->index,

                path_without_prefix,

                buffer, size);

      out = buffer;

    }

    compressed_size = (method == ZIP_METHOD_STORE) ? size : 0;

  } else {

    return error(_("unsupported file mode: 0%o (SHA1: %s)"), mode,

        oid_to_hex(oid));

  }

  if (creator_version > max_creator_version)

    max_creator_version = creator_version;

  if (buffer && method == ZIP_METHOD_DEFLATE) {

    out = deflated = zlib_deflate_raw(buffer, size,

              args->compression_level,

              &compressed_size);

    if (!out || compressed_size >= size) {

      out = buffer;

      method = ZIP_METHOD_STORE;

      compressed_size = size;

    }

  }

  copy_le16(extra.magic, 0x5455);

  copy_le16(extra.extra_size, ZIP_EXTRA_MTIME_PAYLOAD_SIZE);

  extra.flags[0] = 1; /* just mtime */

  copy_le32(extra.mtime, args->time);

  if (size > 0xffffffff || compressed_size > 0xffffffff)

    need_zip64_extra = 1;

  if (stream && size > 0x7fffffff)

    need_zip64_extra = 1;

  if (need_zip64_extra)

    version_needed = 45;

  copy_le32(header.magic, 0x04034b50);

  copy_le16(header.version, version_needed);

  copy_le16(header.flags, flags);

  copy_le16(header.compression_method, method);

  copy_le16(header.mtime, zip_time);

  copy_le16(header.mdate, zip_date);

  if (need_zip64_extra) {

    set_zip_header_data_desc(&header, 0xffffffff, 0xffffffff, crc);

    header_extra_size += ZIP64_EXTRA_SIZE;

  } else {

    set_zip_header_data_desc(&header, size, compressed_size, crc);

  }

  copy_le16(header.filename_length, pathlen);

  copy_le16(header.extra_length, header_extra_size);

  write_or_die(1, &header, ZIP_LOCAL_HEADER_SIZE);

  zip_offset += ZIP_LOCAL_HEADER_SIZE;

  write_or_die(1, path, pathlen);

  zip_offset += pathlen;

  write_or_die(1, &extra, ZIP_EXTRA_MTIME_SIZE);

  zip_offset += ZIP_EXTRA_MTIME_SIZE;

  if (need_zip64_extra) {

    copy_le16(extra64.magic, 0x0001);

    copy_le16(extra64.extra_size, ZIP64_EXTRA_PAYLOAD_SIZE);

    copy_le64(extra64.size, size);

    copy_le64(extra64.compressed_size, compressed_size);

    write_or_die(1, &extra64, ZIP64_EXTRA_SIZE);

    zip_offset += ZIP64_EXTRA_SIZE;

  }

  if (stream && method == ZIP_METHOD_STORE) {

    unsigned char buf[STREAM_BUFFER_SIZE];

    ssize_t readlen;

    for (;;) {

      readlen = read_istream(stream, buf, sizeof(buf));

      if (readlen <= 0)

        break;

      crc = crc32(crc, buf, readlen);

      if (is_binary == -1)

        is_binary = entry_is_binary(args->repo->index,

                  path_without_prefix,

                  buf, readlen);

      write_or_die(1, buf, readlen);

    }

    close_istream(stream);

    if (readlen)

      return readlen;

    compressed_size = size;

    zip_offset += compressed_size;

    write_zip_data_desc(size, compressed_size, crc);

  } else if (stream && method == ZIP_METHOD_DEFLATE) {

    unsigned char buf[STREAM_BUFFER_SIZE];

    ssize_t readlen;

    git_zstream zstream;

    int result;

    size_t out_len;

    unsigned char compressed[STREAM_BUFFER_SIZE * 2];

    git_deflate_init_raw(&zstream, args->compression_level);

    compressed_size = 0;

    zstream.next_out = compressed;

    zstream.avail_out = sizeof(compressed);

    for (;;) {

      readlen = read_istream(stream, buf, sizeof(buf));

      if (readlen <= 0)

        break;

      crc = crc32(crc, buf, readlen);

      if (is_binary == -1)

        is_binary = entry_is_binary(args->repo->index,

                  path_without_prefix,

                  buf, readlen);

      zstream.next_in = buf;

      zstream.avail_in = readlen;

      result = git_deflate(&zstream, 0);

      if (result != Z_OK)

        die(_("deflate error (%d)"), result);

      out_len = zstream.next_out - compressed;

      if (out_len > 0) {

        write_or_die(1, compressed, out_len);

        compressed_size += out_len;

        zstream.next_out = compressed;

        zstream.avail_out = sizeof(compressed);

      }

    }

    close_istream(stream);

    if (readlen)

      return readlen;

    zstream.next_in = buf;

    zstream.avail_in = 0;

    result = git_deflate(&zstream, Z_FINISH);

    if (result != Z_STREAM_END)

      die("deflate error (%d)", result);

    git_deflate_end(&zstream);

    out_len = zstream.next_out - compressed;

    write_or_die(1, compressed, out_len);

    compressed_size += out_len;

    zip_offset += compressed_size;

    write_zip_data_desc(size, compressed_size, crc);

  } else if (compressed_size > 0) {

    write_or_die(1, out, compressed_size);

    zip_offset += compressed_size;

  }

  free(deflated);

  if (compressed_size > 0xffffffff || size > 0xffffffff ||

      offset > 0xffffffff) {

    if (compressed_size >= 0xffffffff)

      zip64_dir_extra_payload_size += 8;

    if (size >= 0xffffffff)

      zip64_dir_extra_payload_size += 8;

    if (offset >= 0xffffffff)

      zip64_dir_extra_payload_size += 8;

    zip_dir_extra_size += 2 + 2 + zip64_dir_extra_payload_size;

  }

  strbuf_add_le(&zip_dir, 4, 0x02014b50); /* magic */

  strbuf_add_le(&zip_dir, 2, creator_version);

  strbuf_add_le(&zip_dir, 2, version_needed);

  strbuf_add_le(&zip_dir, 2, flags);

  strbuf_add_le(&zip_dir, 2, method);

  strbuf_add_le(&zip_dir, 2, zip_time);

  strbuf_add_le(&zip_dir, 2, zip_date);

  strbuf_add_le(&zip_dir, 4, crc);

  strbuf_add_le(&zip_dir, 4, clamp32(compressed_size));

  strbuf_add_le(&zip_dir, 4, clamp32(size));

  strbuf_add_le(&zip_dir, 2, pathlen);

  strbuf_add_le(&zip_dir, 2, zip_dir_extra_size);

  strbuf_add_le(&zip_dir, 2, 0);    /* comment length */

  strbuf_add_le(&zip_dir, 2, 0);    /* disk */

  strbuf_add_le(&zip_dir, 2, !is_binary);

  strbuf_add_le(&zip_dir, 4, attr2);

  strbuf_add_le(&zip_dir, 4, clamp32(offset));

  strbuf_add(&zip_dir, path, pathlen);

  strbuf_add(&zip_dir, &extra, ZIP_EXTRA_MTIME_SIZE);

  if (zip64_dir_extra_payload_size) {

    strbuf_add_le(&zip_dir, 2, 0x0001); /* magic */

    strbuf_add_le(&zip_dir, 2, zip64_dir_extra_payload_size);

    if (size >= 0xffffffff)

      strbuf_add_le(&zip_dir, 8, size);

    if (compressed_size >= 0xffffffff)

      strbuf_add_le(&zip_dir, 8, compressed_size);

    if (offset >= 0xffffffff)

      strbuf_add_le(&zip_dir, 8, offset);

  }

  zip_dir_entries++;

  return 0;

}

static void write_zip64_trailer(void)

{

  struct zip64_dir_trailer trailer64;

  struct zip64_dir_trailer_locator locator64;

  copy_le32(trailer64.magic, 0x06064b50);

  copy_le64(trailer64.record_size, ZIP64_DIR_TRAILER_RECORD_SIZE);

  copy_le16(trailer64.creator_version, max_creator_version);

  copy_le16(trailer64.version, 45);

  copy_le32(trailer64.disk, 0);

  copy_le32(trailer64.directory_start_disk, 0);

  copy_le64(trailer64.entries_on_this_disk, zip_dir_entries);

  copy_le64(trailer64.entries, zip_dir_entries);

  copy_le64(trailer64.size, zip_dir.len);

  copy_le64(trailer64.offset, zip_offset);

  copy_le32(locator64.magic, 0x07064b50);

  copy_le32(locator64.disk, 0);

  copy_le64(locator64.offset, zip_offset + zip_dir.len);

  copy_le32(locator64.number_of_disks, 1);

  write_or_die(1, &trailer64, ZIP64_DIR_TRAILER_SIZE);

  write_or_die(1, &locator64, ZIP64_DIR_TRAILER_LOCATOR_SIZE);

}

static void write_zip_trailer(const struct object_id *oid)

{

  struct zip_dir_trailer trailer;

  int clamped = 0;

  copy_le32(trailer.magic, 0x06054b50);

  copy_le16(trailer.disk, 0);

  copy_le16(trailer.directory_start_disk, 0);

  copy_le16_clamp(trailer.entries_on_this_disk, zip_dir_entries,

      &clamped);

  copy_le16_clamp(trailer.entries, zip_dir_entries, &clamped);

  copy_le32(trailer.size, zip_dir.len);

  copy_le32_clamp(trailer.offset, zip_offset, &clamped);

  copy_le16(trailer.comment_length, oid ? the_hash_algo->hexsz : 0);

  write_or_die(1, zip_dir.buf, zip_dir.len);

  if (clamped)

    write_zip64_trailer();

  write_or_die(1, &trailer, ZIP_DIR_TRAILER_SIZE);

  if (oid)

    write_or_die(1, oid_to_hex(oid), the_hash_algo->hexsz);

}

static void dos_time(timestamp_t *timestamp, int *dos_date, int *dos_time)

{

  time_t time;

  struct tm tm;

  if (date_overflows(*timestamp))

    die(_("timestamp too large for this system: %"PRItime),

        *timestamp);

  time = (time_t)*timestamp;

  localtime_r(&time, &tm);

  *timestamp = time;

  *dos_date = tm.tm_mday + (tm.tm_mon + 1) * 32 +

        (tm.tm_year + 1900 - 1980) * 512;

  *dos_time = tm.tm_sec / 2 + tm.tm_min * 32 + tm.tm_hour * 2048;

}

static int archive_zip_config(const char *var, const char *value,

            const struct config_context *ctx UNUSED,

            void *data UNUSED)

{

  return userdiff_config(var, value);

}

static int write_zip_archive(const struct archiver *ar UNUSED,

           struct archiver_args *args)

{

  int err;

  git_config(archive_zip_config, NULL);

  dos_time(&args->time, &zip_date, &zip_time);

  strbuf_init(&zip_dir, 0);

  err = write_archive_entries(args, write_zip_entry);

  if (!err)

    write_zip_trailer(args->commit_oid);

  strbuf_release(&zip_dir);

  return err;

}

static struct archiver zip_archiver = {

  .name = "zip",

  .write_archive = write_zip_archive,

  .flags = ARCHIVER_WANT_COMPRESSION_LEVELS|ARCHIVER_REMOTE,

};

void init_zip_archiver(void)

{

  register_archiver(&zip_archiver);

}