/* vi:set et sw=2 sts=2 cin cino=t0,f0,(0,{s,>2s,n-s,^-s,e-s:
 * Copyright © 2024 Red Hat, Inc
 *
 * This program 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.
 *
 * This library 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 this library. If not, see <http://www.gnu.org/licenses/>.
 *
 * Authors:
 *       Owen Taylor <otaylor@redhat.com>
 */

#include <glib/gi18n-lib.h>

#include "flatpak-docker-reference-private.h"
#include "flatpak-image-source-private.h"
#include "flatpak-oci-registry-private.h"

struct _FlatpakImageSource
{
  GObject parent;

  FlatpakOciRegistry *registry;
  char *repository;
  char *digest;
  char *delta_url;

  FlatpakOciManifest *manifest;
  size_t manifest_size;
  FlatpakOciImage *image_config;
};

G_DEFINE_TYPE (FlatpakImageSource, flatpak_image_source, G_TYPE_OBJECT)

static void
flatpak_image_source_finalize (GObject *object)
{
  FlatpakImageSource *self = FLATPAK_IMAGE_SOURCE (object);

  g_clear_object (&self->registry);
  g_clear_pointer (&self->repository, g_free);
  g_clear_pointer (&self->digest, g_free);
  g_clear_pointer (&self->delta_url, g_free);
  g_clear_object (&self->manifest);
  g_clear_object (&self->image_config);

  G_OBJECT_CLASS (flatpak_image_source_parent_class)->finalize (object);
}

static void
flatpak_image_source_class_init (FlatpakImageSourceClass *klass)
{
  GObjectClass *object_class = G_OBJECT_CLASS (klass);

  object_class->finalize = flatpak_image_source_finalize;
}

static void
flatpak_image_source_init (FlatpakImageSource *self)
{
}

FlatpakImageSource *
flatpak_image_source_new (FlatpakOciRegistry *registry,
                          const char         *repository,
                          const char         *digest,
                          GCancellable       *cancellable,
                          GError            **error)
{
  g_autoptr(FlatpakImageSource) self = NULL;
  g_autoptr(FlatpakOciVersioned) versioned = NULL;

  if (!g_str_has_prefix (digest, "sha256:"))
    {
      flatpak_fail_error (error, FLATPAK_ERROR_INVALID_DATA, _("Only sha256 image checksums are supported"));
      return NULL;
    }

  self = g_object_new (FLATPAK_TYPE_IMAGE_SOURCE, NULL);
  self->registry = g_object_ref (registry);
  self->repository = g_strdup (repository);
  self->digest = g_strdup (digest);

  versioned = flatpak_oci_registry_load_versioned (self->registry, self->repository,
                                                   self->digest, NULL, &self->manifest_size,
                                                   cancellable, error);
  if (versioned == NULL)
    return NULL;

  if (!FLATPAK_IS_OCI_MANIFEST (versioned))
    {
      flatpak_fail_error (error, FLATPAK_ERROR_INVALID_DATA, _("Image is not a manifest"));
      return NULL;
    }

  self->manifest = FLATPAK_OCI_MANIFEST (g_steal_pointer (&versioned));

  if (self->manifest->config.digest == NULL)
    {
      flatpak_fail_error (error, FLATPAK_ERROR_INVALID_DATA, _("Image is not a manifest"));
      return NULL;
    }

  self->image_config =
    flatpak_oci_registry_load_image_config (self->registry,
                                            self->repository,
                                            self->manifest->config.digest,
                                            (const char **) self->manifest->config.urls,
                                            NULL, cancellable, error);
  if (self->image_config == NULL)
    return NULL;

  if (flatpak_image_source_get_ref (self) == NULL)
    {
      flatpak_fail_error (error, FLATPAK_ERROR_INVALID_DATA, _("No org.flatpak.ref found in image"));
      return NULL;
    }

  return g_steal_pointer (&self);
}

static FlatpakImageSource *
flatpak_image_source_new_local_for_registry (FlatpakOciRegistry *registry,
                                             const char         *reference,
                                             GCancellable       *cancellable,
                                             GError            **error)
{
  g_autoptr(FlatpakOciIndex) index = NULL;
  const FlatpakOciManifestDescriptor *desc;

  index = flatpak_oci_registry_load_index (registry, cancellable, error);
  if (index == NULL)
    return NULL;

  if (reference)
    {
      desc = flatpak_oci_index_get_manifest (index, reference);
      if (desc == NULL)
        {
          flatpak_fail (error, _("Ref '%s' not found in registry"), reference);
          return NULL;
        }
    }
  else
    {
      desc = flatpak_oci_index_get_only_manifest (index);
      if (desc == NULL)
        {
          flatpak_fail (error, _("Multiple images in registry, specify a ref with --ref"));
          return NULL;
        }
    }

  return flatpak_image_source_new (registry, NULL, desc->parent.digest, cancellable, error);
}

FlatpakImageSource *
flatpak_image_source_new_local (GFile        *file,
                                const char   *reference,
                                GCancellable *cancellable,
                                GError      **error)
{
  g_autofree char *dir_uri = NULL;
  g_autoptr(FlatpakOciRegistry) registry = NULL;

  dir_uri = g_file_get_uri (file);
  registry = flatpak_oci_registry_new (dir_uri, FALSE, -1, cancellable, error);
  if (registry == NULL)
    return NULL;

  return flatpak_image_source_new_local_for_registry (registry, reference, cancellable, error);
}

FlatpakImageSource *
flatpak_image_source_new_remote (const char   *uri,
                                 const char   *oci_repository,
                                 const char   *digest,
                                 const char   *token,
                                 const char   *signature_lookaside,
                                 GCancellable *cancellable,
                                 GError      **error)
{
  g_autoptr(FlatpakOciRegistry) registry = NULL;

  registry = flatpak_oci_registry_new (uri, FALSE, -1, cancellable, error);
  if (!registry)
    return NULL;

  flatpak_oci_registry_set_token (registry, token);
  flatpak_oci_registry_set_signature_lookaside (registry, signature_lookaside);

  return flatpak_image_source_new (registry, oci_repository, digest, cancellable, error);
}

/* Parse an oci: or oci-archive: image location into a path
 * and an optional reference
 */
static void
get_path_and_reference (const char *image_location,
                        GFile     **path,
                        char      **reference)
{
  g_autofree char *path_str = NULL;
  const char *bare;
  const char *colon;

  colon = strchr (image_location, ':');
  g_assert (colon != NULL);

  bare = colon + 1;
  colon = strchr (bare, ':');

  if (colon)
     {
      path_str = g_strndup (bare, colon - bare);
      *reference = g_strdup (colon + 1);
    }
  else
    {
      path_str = g_strdup (bare);
      *reference = NULL;
    }

  *path = g_file_new_for_path (path_str);
}

FlatpakImageSource *
flatpak_image_source_new_for_location (const char   *location,
                                       GCancellable *cancellable,
                                       GError      **error)
{
  if (g_str_has_prefix (location, "oci:"))
    {
      g_autoptr(GFile) path = NULL;
      g_autofree char *reference = NULL;

      get_path_and_reference (location, &path, &reference);

      return flatpak_image_source_new_local (path, reference, cancellable, error);
    }
  else if (g_str_has_prefix (location, "oci-archive:"))
    {
      g_autoptr(FlatpakOciRegistry) registry = NULL;
      g_autoptr(GFile) path = NULL;
      g_autofree char *reference = NULL;

      get_path_and_reference (location, &path, &reference);

      registry = flatpak_oci_registry_new_for_archive (path, cancellable, error);
      if (registry == NULL)
        return NULL;

      return flatpak_image_source_new_local_for_registry (registry, reference, cancellable, error);
    }
  else if (g_str_has_prefix (location, "docker:"))
    {
      g_autoptr(FlatpakOciRegistry) registry = NULL;
      g_autoptr(FlatpakDockerReference) docker_reference = NULL;
      g_autofree char *local_digest = NULL;
      const char *repository = NULL;

      if (!g_str_has_prefix (location, "docker://"))
        {
          flatpak_fail (error, "docker: location must start docker://");
          return NULL;
        }

      docker_reference = flatpak_docker_reference_parse (location + 9, error);
      if (docker_reference == NULL)
        return NULL;

      registry = flatpak_oci_registry_new (flatpak_docker_reference_get_uri (docker_reference),
                                           FALSE, -1, cancellable, error);
      if (registry == NULL)
        return NULL;

      repository = flatpak_docker_reference_get_repository (docker_reference);

      local_digest = g_strdup (flatpak_docker_reference_get_digest (docker_reference));
      if (local_digest == NULL)
        {
          g_autoptr(GBytes) bytes = NULL;
          g_autoptr(FlatpakOciVersioned) versioned = NULL;
          const char *tag = flatpak_docker_reference_get_tag (docker_reference);

          if (tag == NULL)
            tag = "latest";

          bytes = flatpak_oci_registry_load_blob (registry, repository, TRUE, tag,
                                                  NULL, NULL, cancellable, error);
          if (!bytes)
            return NULL;

          versioned = flatpak_oci_versioned_from_json (bytes, NULL, error);
          if (!versioned)
            return NULL;

          if (FLATPAK_IS_OCI_MANIFEST (versioned))
            {
              g_autofree char *checksum = NULL;

              checksum = g_compute_checksum_for_bytes (G_CHECKSUM_SHA256, bytes);
              local_digest = g_strconcat ("sha256:", checksum, NULL);
            }
          else if (FLATPAK_IS_OCI_INDEX (versioned))
            {
              const char *oci_arch = flatpak_arch_to_oci_arch (flatpak_get_arch ());
              FlatpakOciManifestDescriptor *descriptor;

              descriptor = flatpak_oci_index_get_manifest_for_arch (FLATPAK_OCI_INDEX (versioned), oci_arch);
              if (descriptor == NULL)
                {
                  flatpak_fail_error (error, FLATPAK_ERROR_INVALID_DATA,
                                      "Can't find manifest for %s in image index", oci_arch);
                  return NULL;
                }

              local_digest = g_strdup (descriptor->parent.digest);
            }
        }

      return flatpak_image_source_new (registry, repository, local_digest, cancellable, error);
    }
  else
    {
      flatpak_fail (error, "unsupported image location: %s", location);
      return NULL;
    }
}

void
flatpak_image_source_set_delta_url (FlatpakImageSource *self,
                                    const char         *delta_url)
{
  g_free (self->delta_url);
  self->delta_url = g_strdup (delta_url);
}

const char *
flatpak_image_source_get_delta_url (FlatpakImageSource *self)
{
  return self->delta_url;
}

FlatpakOciRegistry *
flatpak_image_source_get_registry (FlatpakImageSource *self)
{
  return self->registry;
}

const char *
flatpak_image_source_get_oci_repository (FlatpakImageSource *self)
{
  return self->repository;
}

const char *
flatpak_image_source_get_digest (FlatpakImageSource *self)
{
  return self->digest;
}

FlatpakOciManifest *
flatpak_image_source_get_manifest (FlatpakImageSource *self)
{
  return self->manifest;
}

size_t
flatpak_image_source_get_manifest_size (FlatpakImageSource *self)
{
  return self->manifest_size;
}

FlatpakOciImage *
flatpak_image_source_get_image_config (FlatpakImageSource *self)
{
  return self->image_config;
}

const char *
flatpak_image_source_get_ref (FlatpakImageSource *self)
{
  GHashTable *labels = flatpak_oci_image_get_labels (self->image_config);

  return g_hash_table_lookup (labels, "org.flatpak.ref");
}

const char *
flatpak_image_source_get_metadata (FlatpakImageSource *self)
{
  GHashTable *labels = flatpak_oci_image_get_labels (self->image_config);

  return g_hash_table_lookup (labels, "org.flatpak.metadata");
}

const char *
flatpak_image_source_get_commit (FlatpakImageSource *self)
{
  GHashTable *labels = flatpak_oci_image_get_labels (self->image_config);

  return g_hash_table_lookup (labels, "org.flatpak.commit");
}

const char *
flatpak_image_source_get_parent_commit (FlatpakImageSource *self)
{
  GHashTable *labels = flatpak_oci_image_get_labels (self->image_config);

  return g_hash_table_lookup (labels, "org.flatpak.parent-commit");
}

guint64
flatpak_image_source_get_commit_timestamp (FlatpakImageSource *self)
{
  GHashTable *labels = flatpak_oci_image_get_labels (self->image_config);
  const char *oci_timestamp = g_hash_table_lookup (labels, "org.flatpak.timestamp");

  if (oci_timestamp != NULL)
    return g_ascii_strtoull (oci_timestamp, NULL, 10);
  else
    return 0;
}

const char *
flatpak_image_source_get_commit_subject (FlatpakImageSource *self)
{
  GHashTable *labels = flatpak_oci_image_get_labels (self->image_config);

  return g_hash_table_lookup (labels, "org.flatpak.subject");
}

const char *
flatpak_image_source_get_commit_body (FlatpakImageSource *self)
{
  GHashTable *labels = flatpak_oci_image_get_labels (self->image_config);

  return g_hash_table_lookup (labels, "org.flatpak.body");
}

void
flatpak_image_source_build_commit_metadata (FlatpakImageSource *self,
                                            GVariantBuilder    *metadata_builder)
{
  GHashTable *labels = flatpak_oci_image_get_labels (self->image_config);
  GHashTableIter iter;
  const char *key;
  const char *value;

  g_hash_table_iter_init (&iter, labels);
  while (g_hash_table_iter_next (&iter, (gpointer *)&key, (gpointer *)&value))
    {
      g_autoptr(GVariant) data = NULL;
      uint8_t *bin;
      size_t bin_len;

      if (!g_str_has_prefix (key, "org.flatpak.commit-metadata."))
        continue;

      key += strlen ("org.flatpak.commit-metadata.");

      bin = g_base64_decode (value, &bin_len);
      data = g_variant_ref_sink (g_variant_new_from_data (G_VARIANT_TYPE ("v"),
                                                          bin,
                                                          bin_len,
                                                          FALSE,
                                                          g_free,
                                                          bin));
      g_variant_builder_add (metadata_builder, "{s@v}", key, data);
    }
}

GVariant *
flatpak_image_source_make_fake_commit (FlatpakImageSource *self)
{
  const char *parent = NULL;
  g_autoptr(GVariantBuilder) metadata_builder = g_variant_builder_new (G_VARIANT_TYPE ("a{sv}"));
  g_autoptr(GVariant) metadata_v = NULL;

  flatpak_image_source_build_commit_metadata (self, metadata_builder);
  metadata_v = g_variant_ref_sink (g_variant_builder_end (metadata_builder));

  parent = flatpak_image_source_get_parent_commit (self);

  /* This isn't going to be exactly the same as the reconstructed one from the pull, because we don't have the contents, but its useful to get metadata */
  return
    g_variant_ref_sink (g_variant_new ("(@a{sv}@ay@a(say)sst@ay@ay)",
                                       metadata_v,
                                       parent ? ostree_checksum_to_bytes_v (parent) :  g_variant_new_from_data (G_VARIANT_TYPE ("ay"), NULL, 0, FALSE, NULL, NULL),
                                       g_variant_new_array (G_VARIANT_TYPE ("(say)"), NULL, 0),
                                       flatpak_image_source_get_commit_subject (self),
                                       flatpak_image_source_get_commit_body (self),
                                       GUINT64_TO_BE (flatpak_image_source_get_commit_timestamp (self)),
                                       ostree_checksum_to_bytes_v ("0000000000000000000000000000000000000000000000000000000000000000"),
                                       ostree_checksum_to_bytes_v ("0000000000000000000000000000000000000000000000000000000000000000")));
}

GVariant *
flatpak_image_source_make_summary_metadata (FlatpakImageSource *self)
{
  g_autoptr(GVariantBuilder) ref_metadata_builder = NULL;

  ref_metadata_builder = g_variant_builder_new (G_VARIANT_TYPE ("a{sv}"));

  if (self->repository)
    g_variant_builder_add (ref_metadata_builder, "{sv}", "xa.oci-repository",
                          g_variant_new_string (self->repository));
  if (self->delta_url)
    g_variant_builder_add (ref_metadata_builder, "{sv}", "xa.delta-url",
                           g_variant_new_string (self->delta_url));

  return g_variant_ref_sink (g_variant_builder_end (ref_metadata_builder));
}