#include "git-compat-util.h"

#include "abspath.h"

#include "chdir-notify.h"

#include "list.h"

#include "path.h"

#include "strbuf.h"

#include "trace.h"

struct chdir_notify_entry {

  const char *name;

  chdir_notify_callback cb;

  void *data;

  struct list_head list;

};

static LIST_HEAD(chdir_notify_entries);

void chdir_notify_register(const char *name,

         chdir_notify_callback cb,

         void *data)

{

  struct chdir_notify_entry *e = xmalloc(sizeof(*e));

  e->name = name;

  e->cb = cb;

  e->data = data;

  list_add_tail(&e->list, &chdir_notify_entries);

}

void chdir_notify_unregister(const char *name, chdir_notify_callback cb,

           void *data)

{

  struct list_head *pos, *p;

  list_for_each_safe(pos, p, &chdir_notify_entries) {

    struct chdir_notify_entry *e =

      list_entry(pos, struct chdir_notify_entry, list);

    if (e->cb != cb || e->data != data || !e->name != !name ||

        (e->name && strcmp(e->name, name)))

      continue;

    list_del(pos);

    free(e);

  }

}

static void reparent_cb(const char *name,

      const char *old_cwd,

      const char *new_cwd,

      void *data)

{

  char **path = data;

  char *tmp = *path;

  if (!tmp)

    return;

  *path = reparent_relative_path(old_cwd, new_cwd, tmp);

  free(tmp);

  if (name) {

    trace_printf_key(&trace_setup_key,

         "setup: reparent %s to '%s'",

         name, *path);

  }

}

void chdir_notify_reparent(const char *name, char **path)

{

  chdir_notify_register(name, reparent_cb, path);

}

int chdir_notify(const char *new_cwd)

{

  struct strbuf old_cwd = STRBUF_INIT;

  struct list_head *pos;

  if (strbuf_getcwd(&old_cwd) < 0)

    return -1;

  if (chdir(new_cwd) < 0) {

    int saved_errno = errno;

    strbuf_release(&old_cwd);

    errno = saved_errno;

    return -1;

  }

  trace_printf_key(&trace_setup_key,

       "setup: chdir from '%s' to '%s'",

       old_cwd.buf, new_cwd);

  list_for_each(pos, &chdir_notify_entries) {

    struct chdir_notify_entry *e =

      list_entry(pos, struct chdir_notify_entry, list);

    e->cb(e->name, old_cwd.buf, new_cwd, e->data);

  }

  strbuf_release(&old_cwd);

  return 0;

}

char *reparent_relative_path(const char *old_cwd,

           const char *new_cwd,

           const char *path)

{

  char *ret, *full;

  if (is_absolute_path(path))

    return xstrdup(path);

  full = xstrfmt("%s/%s", old_cwd, path);

  ret = xstrdup(remove_leading_path(full, new_cwd));

  free(full);

  return ret;

}