/* SPDX-FileCopyrightText: 2023 Blender Authors
 *
 * SPDX-License-Identifier: GPL-2.0-or-later */

/** \file
 * \ingroup bke
 *
 * \warning All paths manipulated by this API are assumed to be either constant char buffers of
 * `FILE_MAX` size, or allocated char buffers not bigger than `FILE_MAX`.
 */

/* TODO: Make this module handle a bit more safely string length, instead of assuming buffers are
 * FILE_MAX length etc. */

#pragma once

#include <cstddef>

#include "BLI_enum_flags.hh"
#include "BLI_function_ref.hh"
#include "BLI_string_ref.hh"

namespace blender {

struct ID;
struct Main;
struct ReportList;

/** \name Core `foreach_path` API.
 * \{ */

/**
 * Flags controlling the behavior of the generic BPath API.
 *
 * Note: these are referred to by `rna_enum_file_path_foreach_flag_items`, so make sure that any
 * new enum items are added there too.
 */
enum eBPathForeachFlag {
  /**
   * Ensures the `absolute_base_path` member of #BPathForeachPathData is initialized properly with
   * the path of the current .blend file. This can be used by the callbacks to convert relative
   * paths to absolute ones.
   */
  BKE_BPATH_FOREACH_PATH_ABSOLUTE = (1 << 0),
  /** Skip paths of linked IDs. */
  BKE_BPATH_FOREACH_PATH_SKIP_LINKED = (1 << 1),
  /** Skip paths when their matching data is packed. */
  BKE_BPATH_FOREACH_PATH_SKIP_PACKED = (1 << 2),
  /**
   * Resolve tokens within a virtual filepath to a single, concrete, filepath. Currently only used
   * for UDIM tiles.
   */
  BKE_BPATH_FOREACH_PATH_RESOLVE_TOKEN = (1 << 3),
  /**
   * Skip weak reference paths. Those paths are typically 'nice to have' extra information, but are
   * not used as actual source of data by the current .blend file.
   *
   * NOTE: Currently this only concerns the weak reference to a library file stored in
   * `ID::library_weak_reference`.
   */
  BKE_BPATH_TRAVERSE_SKIP_WEAK_REFERENCES = (1 << 5),

  /**
   * Flags not affecting the generic BPath API. Those may be used by specific IDTypeInfo
   * `foreach_path` implementations and/or callbacks to implement specific behaviors.
   */

  /**
   * Skip paths where a single dir is used with an array of files, eg. sequence strip images or
   * point-caches. In this case only the first file path is processed.
   *
   * This is needed for directory manipulation callbacks which might otherwise modify the same
   * directory multiple times.
   */
  BKE_BPATH_FOREACH_PATH_SKIP_MULTIFILE = (1 << 8),
  /**
   * Reload data (when the path is edited).
   * \note Only used by Image #IDType currently.
   */
  BKE_BPATH_FOREACH_PATH_RELOAD_EDITED = (1 << 9),
  /**
   * Expand template tokens in virtual file paths to all matching concrete paths, invoking the
   * callback once per expanded path. Currently only used for UDIM tiles. These paths can not
   * be edited.
   */
  BKE_BPATH_FOREACH_PATH_EXPAND_TOKENS = (1 << 10),
  /**
   * Expand image sequences and similar multi-file resources to all individual file paths on disk,
   * invoking the callback once per file. These paths can not be edited.
   */
  BKE_BPATH_FOREACH_PATH_EXPAND_SEQUENCES = (1 << 11),
  /**
   * Visit cache files, for example texture cache files associated with images. These paths can
   * not be edited.
   */
  BKE_BPATH_FOREACH_PATH_EXPAND_CACHES = (1 << 12),
};
ENUM_OPERATORS(eBPathForeachFlag)

struct BPathForeachPathData;

/**
 * Callback used to iterate over an ID's file paths.
 * \param path_dst: Optionally write to the path (for callbacks that manipulate the path).
 * \note When #BKE_BPATH_FOREACH_PATH_ABSOLUTE us used, `path_src` will be absolute and `path_dst`
 * can be used to access the original path.
 * \param path_dst_maxncpy: The buffer size of `path_dst` including the null byte.
 * \warning Actions such as #BLI_path_abs & #BLI_path_rel must not be called directly
 * on `path_dst` as they assume #FILE_MAX size which may not be the case.
 *
 * \return `true` if the path has been changed, and in that case,
 * result must be written to `path_dst`.
 */
using BPathForeachPathFunctionCallback = bool (*)(BPathForeachPathData *bpath_data,
                                                  char *path_dst,
                                                  size_t path_dst_maxncpy,
                                                  const char *path_src);

/** Storage for common data needed across the BPath 'foreach_path' code. */
struct BPathForeachPathData {
  Main *bmain;

  BPathForeachPathFunctionCallback callback_function;
  eBPathForeachFlag flag;

  void *user_data;

  /* 'Private' data, caller don't need to set those. */

  /**
   * The root to use as base for relative paths.
   * Only set if #BKE_BPATH_FOREACH_PATH_ABSOLUTE flag is set, NULL otherwise.
   */
  const char *absolute_base_path;

  /** ID owning the path being processed. */
  ID *owner_id;

  /**
   * IDTypeInfo callbacks are responsible to set this boolean if they modified one or more paths.
   */
  bool is_path_modified;

  /**
   * Set while visiting a path expanded from a UDIM tile or sequence frame.
   * These paths can not be edited.
   */
  bool is_expanded;
  /**
   * Set while visiting a cache file path, like a texture cache file.
   * These paths can not be edited.
   */
  bool is_cache;
  /**
   * Set while visiting a read-only path that callbacks can not edit.
   */
  bool is_readonly;
};

/** Run `bpath_data.callback_function` on all paths contained in `id`. */
void BKE_bpath_foreach_path_id(BPathForeachPathData *bpath_data, ID *id);

/** Run `bpath_data.callback_function` on all paths of all IDs in `bmain`. */
void BKE_bpath_foreach_path_main(BPathForeachPathData *bpath_data);

/** \} */

/** \name Helpers to handle common cases from `IDTypeInfo`'s `foreach_path` functions.
 * \{ */

/* TODO: Investigate using macros around those calls to check a bit better about actual
 * strings/buffers length (e,g, with static asserts). */

/**
 * Run the callback on a path, replacing the content of the string as needed.
 *
 * \param path: A fixed, FILE_MAX-sized char buffer.
 *
 * \return true is \a path was modified, false otherwise.
 */
bool BKE_bpath_foreach_path_fixed_process(BPathForeachPathData *bpath_data,
                                          char *path,
                                          size_t path_maxncpy);

/**
 * Run the callback on a read-only path, any edits will be discarded.
 *
 * \param path: A fixed, FILE_MAX-sized char buffer.
 */
void BKE_bpath_foreach_path_readonly_process(BPathForeachPathData *bpath_data, const char *path);

/**
 * Run the callback on every existing file on disk matching a `<head><digits><tail>`
 * numbered-sequence pattern derived from `abs_filepath`. If `abs_filepath` itself is not a
 * numbered sequence, the callback is invoked once with `abs_filepath` if it exists.
 */
void BKE_bpath_sequence_filepaths_foreach(
    const char *abs_filepath,
    blender::FunctionRef<void(blender::StringRef frame_filepath)> callback);

/**
 * Run the callback on a (directory + file) path, replacing the content of the two strings as
 * needed.
 *
 * \param path_dir: A fixed, FILE_MAXDIR-sized char buffer.
 * \param path_file: A fixed, FILE_MAXFILE-sized char buffer.
 *
 * \return true is \a path_dir and/or \a path_file were modified, false otherwise.
 */
bool BKE_bpath_foreach_path_dirfile_fixed_process(BPathForeachPathData *bpath_data,
                                                  char *path_dir,
                                                  size_t path_dir_maxncpy,
                                                  char *path_file,
                                                  size_t path_file_maxncpy);

/**
 * Run the callback on a path, replacing the content of the string as needed.
 *
 * \param path: A pointer to a MEM-allocated string. If modified, it will be freed and replaced by
 * a new allocated string.
 * \note path is expected to be FILE_MAX size or smaller.
 *
 * \return true is \a path was modified and re-allocated, false otherwise.
 */
bool BKE_bpath_foreach_path_allocated_process(BPathForeachPathData *bpath_data, char **path);

/** \} */

/** \name High level features.
 * \{ */

/** Check for missing files. */
void BKE_bpath_missing_files_check(Main *bmain, ReportList *reports);

/** A summary of operating on many paths. */
struct BPathSummary {
  int count_total = 0;
  int count_changed = 0;
  int count_failed = 0;
};

void BKE_bpath_summary_report(const BPathSummary &summary, ReportList *reports);

/**
 * Recursively search into given search directory, for all file paths of all IDs in given
 * \a bmain, and replace existing paths as needed.
 *
 * \note The search will happen into the whole search directory tree recursively (with a limit of
 * MAX_DIR_RECURSE), if several files are found matching a searched filename, the biggest one will
 * be used. This is so that things like thumbnails don't get selected instead of the actual image
 * e.g.
 *
 * \param searchpath: The root directory in which the new filepaths should be searched for.
 * \param find_all: If `true`, also search for files which current path is still valid, if `false`
 *                  skip those still valid paths.
 */
void BKE_bpath_missing_files_find(Main *bmain,
                                  const char *searchpath,
                                  ReportList *reports,
                                  bool find_all);

/** Rebase all relative file paths in given \a bmain from \a basedir_src to \a basedir_dst. */
void BKE_bpath_relative_rebase(Main *bmain,
                               const char *basedir_src,
                               const char *basedir_dst,
                               ReportList *reports,
                               BPathSummary *r_summary = nullptr);

/** Make all absolute file paths in given \a bmain relative to given \a basedir. */
void BKE_bpath_relative_convert(Main *bmain,
                                const char *basedir,
                                ReportList *reports,
                                BPathSummary *r_summary = nullptr);

/** Make all relative file paths in given \a bmain absolute, using given \a basedir as root. */
void BKE_bpath_absolute_convert(Main *bmain,
                                const char *basedir,
                                ReportList *reports,
                                BPathSummary *r_summary = nullptr);

/**
 * Temp backup of paths from all IDs in given \a bmain.
 *
 * \return An opaque handle to pass to #BKE_bpath_list_restore and #BKE_bpath_list_free.
 */
void *BKE_bpath_list_backup(Main *bmain, eBPathForeachFlag flag);

/**
 * Restore the temp backup of paths from \a path_list_handle into all IDs in given \a bmain.
 *
 * \note This function assumes that the data in given Main did not change (no
 * addition/deletion/re-ordering of IDs, or their file paths) since the call to
 * #BKE_bpath_list_backup that generated the given \a path_list_handle.
 */
void BKE_bpath_list_restore(Main *bmain, eBPathForeachFlag flag, void *path_list_handle);

/**
 * Free the temp backup of paths in \a path_list_handle.
 *
 * \note This function assumes that the path list has already been restored with a call to
 * #BKE_bpath_list_restore, and is therefore empty.
 */
void BKE_bpath_list_free(void *path_list_handle);

/** \} */

}  // namespace blender