/*

 * Builtin "git interpret-trailers"

 *

 * Copyright (c) 2013, 2014 Christian Couder <chriscool@tuxfamily.org>

 *

 */

#include "builtin.h"

#include "gettext.h"

#include "parse-options.h"

#include "string-list.h"

#include "tempfile.h"

#include "trailer.h"

#include "config.h"

static const char * const git_interpret_trailers_usage[] = {

  N_("git interpret-trailers [--in-place] [--trim-empty]\n"

     "                       [(--trailer (<key>|<key-alias>)[(=|:)<value>])...]\n"

     "                       [--parse] [<file>...]"),

  NULL

};

static enum trailer_where where;

static enum trailer_if_exists if_exists;

static enum trailer_if_missing if_missing;

static int option_parse_where(const struct option *opt,

            const char *arg, int unset UNUSED)

{

  /* unset implies NULL arg, which is handled in our helper */

  return trailer_set_where(opt->value, arg);

}

static int option_parse_if_exists(const struct option *opt,

          const char *arg, int unset UNUSED)

{

  /* unset implies NULL arg, which is handled in our helper */

  return trailer_set_if_exists(opt->value, arg);

}

static int option_parse_if_missing(const struct option *opt,

           const char *arg, int unset UNUSED)

{

  /* unset implies NULL arg, which is handled in our helper */

  return trailer_set_if_missing(opt->value, arg);

}

static void new_trailers_clear(struct list_head *trailers)

{

  struct list_head *pos, *tmp;

  struct new_trailer_item *item;

  list_for_each_safe(pos, tmp, trailers) {

    item = list_entry(pos, struct new_trailer_item, list);

    list_del(pos);

    free(item);

  }

}

static int option_parse_trailer(const struct option *opt,

           const char *arg, int unset)

{

  struct list_head *trailers = opt->value;

  struct new_trailer_item *item;

  if (unset) {

    new_trailers_clear(trailers);

    return 0;

  }

  if (!arg)

    return -1;

  item = xmalloc(sizeof(*item));

  item->text = arg;

  item->where = where;

  item->if_exists = if_exists;

  item->if_missing = if_missing;

  list_add_tail(&item->list, trailers);

  return 0;

}

static int parse_opt_parse(const struct option *opt, const char *arg,

         int unset)

{

  struct process_trailer_options *v = opt->value;

  v->only_trailers = 1;

  v->only_input = 1;

  v->unfold = 1;

  BUG_ON_OPT_NEG(unset);

  BUG_ON_OPT_ARG(arg);

  return 0;

}

static struct tempfile *trailers_tempfile;

static FILE *create_in_place_tempfile(const char *file)

{

  struct stat st;

  struct strbuf filename_template = STRBUF_INIT;

  const char *tail;

  FILE *outfile;

  if (stat(file, &st))

    die_errno(_("could not stat %s"), file);

  if (!S_ISREG(st.st_mode))

    die(_("file %s is not a regular file"), file);

  if (!(st.st_mode & S_IWUSR))

    die(_("file %s is not writable by user"), file);

  /* Create temporary file in the same directory as the original */

  tail = strrchr(file, '/');

  if (tail)

    strbuf_add(&filename_template, file, tail - file + 1);

  strbuf_addstr(&filename_template, "git-interpret-trailers-XXXXXX");

  trailers_tempfile = xmks_tempfile_m(filename_template.buf, st.st_mode);

  strbuf_release(&filename_template);

  outfile = fdopen_tempfile(trailers_tempfile, "w");

  if (!outfile)

    die_errno(_("could not open temporary file"));

  return outfile;

}

static void read_input_file(struct strbuf *sb, const char *file)

{

  if (file) {

    if (strbuf_read_file(sb, file, 0) < 0)

      die_errno(_("could not read input file '%s'"), file);

  } else {

    if (strbuf_read(sb, fileno(stdin), 0) < 0)

      die_errno(_("could not read from stdin"));

  }

  strbuf_complete_line(sb);

}

static void interpret_trailers(const struct process_trailer_options *opts,

             struct list_head *new_trailer_head,

             const char *file)

{

  LIST_HEAD(head);

  struct strbuf sb = STRBUF_INIT;

  struct strbuf trailer_block = STRBUF_INIT;

  struct trailer_info *info;

  FILE *outfile = stdout;

  trailer_config_init();

  read_input_file(&sb, file);

  if (opts->in_place)

    outfile = create_in_place_tempfile(file);

  info = parse_trailers(opts, sb.buf, &head);

  /* Print the lines before the trailers */

  if (!opts->only_trailers)

    fwrite(sb.buf, 1, trailer_block_start(info), outfile);

  if (!opts->only_trailers && !blank_line_before_trailer_block(info))

    fprintf(outfile, "\n");

  if (!opts->only_input) {

    LIST_HEAD(config_head);

    LIST_HEAD(arg_head);

    parse_trailers_from_config(&config_head);

    parse_trailers_from_command_line_args(&arg_head, new_trailer_head);

    list_splice(&config_head, &arg_head);

    process_trailers_lists(&head, &arg_head);

  }

  /* Print trailer block. */

  format_trailers(opts, &head, &trailer_block);

  free_trailers(&head);

  fwrite(trailer_block.buf, 1, trailer_block.len, outfile);

  strbuf_release(&trailer_block);

  /* Print the lines after the trailers as is */

  if (!opts->only_trailers)

    fwrite(sb.buf + trailer_block_end(info), 1, sb.len - trailer_block_end(info), outfile);

  trailer_info_release(info);

  if (opts->in_place)

    if (rename_tempfile(&trailers_tempfile, file))

      die_errno(_("could not rename temporary file to %s"), file);

  strbuf_release(&sb);

}

int cmd_interpret_trailers(int argc, const char **argv, const char *prefix)

{

  struct process_trailer_options opts = PROCESS_TRAILER_OPTIONS_INIT;

  LIST_HEAD(trailers);

  struct option options[] = {

    OPT_BOOL(0, "in-place", &opts.in_place, N_("edit files in place")),

    OPT_BOOL(0, "trim-empty", &opts.trim_empty, N_("trim empty trailers")),

    OPT_CALLBACK(0, "where", &where, N_("placement"),

           N_("where to place the new trailer"), option_parse_where),

    OPT_CALLBACK(0, "if-exists", &if_exists, N_("action"),

           N_("action if trailer already exists"), option_parse_if_exists),

    OPT_CALLBACK(0, "if-missing", &if_missing, N_("action"),

           N_("action if trailer is missing"), option_parse_if_missing),

    OPT_BOOL(0, "only-trailers", &opts.only_trailers, N_("output only the trailers")),

    OPT_BOOL(0, "only-input", &opts.only_input, N_("do not apply trailer.* configuration variables")),

    OPT_BOOL(0, "unfold", &opts.unfold, N_("reformat multiline trailer values as single-line values")),

    OPT_CALLBACK_F(0, "parse", &opts, NULL, N_("alias for --only-trailers --only-input --unfold"),

      PARSE_OPT_NOARG | PARSE_OPT_NONEG, parse_opt_parse),

    OPT_BOOL(0, "no-divider", &opts.no_divider, N_("do not treat \"---\" as the end of input")),

    OPT_CALLBACK(0, "trailer", &trailers, N_("trailer"),

        N_("trailer(s) to add"), option_parse_trailer),

    OPT_END()

  };

  git_config(git_default_config, NULL);

  argc = parse_options(argc, argv, prefix, options,

           git_interpret_trailers_usage, 0);

  if (opts.only_input && !list_empty(&trailers))

    usage_msg_opt(

      _("--trailer with --only-input does not make sense"),

      git_interpret_trailers_usage,

      options);

  if (argc) {

    int i;

    for (i = 0; i < argc; i++)

      interpret_trailers(&opts, &trailers, argv[i]);

  } else {

    if (opts.in_place)

      die(_("no input file given for in-place editing"));

    interpret_trailers(&opts, &trailers, NULL);

  }

  new_trailers_clear(&trailers);

  return 0;

}