/*
 * cnmt.h
 *
 * Copyright (c) 2020, DarkMatterCore <pabloacurielz@gmail.com>.
 *
 * This file is part of nxdumptool (https://github.com/DarkMatterCore/nxdumptool).
 *
 * nxdumptool is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * nxdumptool is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#pragma once

#ifndef __CNMT_H__
#define __CNMT_H__

#include "nca.h"
#include "pfs.h"

#define CNMT_DIGEST_SIZE    SHA256_HASH_SIZE

/// Used to display version numbers in dot notation: "{Major}.{Minor}.{Micro}-{MajorRelstep}.{MinorRelstep}".
typedef struct {
    u32 ContentMetaVersion_MinorRelstep : 8;
    u32 ContentMetaVersion_MajorRelstep : 8;
    u32 ContentMetaVersion_Micro        : 4;
    u32 ContentMetaVersion_Minor        : 6;
    u32 ContentMetaVersion_Major        : 6;
} ContentMetaVersion;

/// Equivalent to NcmContentMetaAttribute.
typedef enum {
    ContentMetaAttribute_IncludesExFatDriver = BIT(0),
    ContentMetaAttribute_Rebootless          = BIT(1),
    ContentMetaAttribute_Compacted           = BIT(2)
} ContentMetaAttribute;

typedef struct {
    u8 ContentMetaInstallState_Committed : 1;
    u8 ContentMetaInstallState_Reserved  : 7;
} ContentMetaInstallState;

/// Extended variation of NcmContentMetaHeader. This is essentially the start of every CNMT file.
/// Depending on the content meta type value, this header may be followed by an additional extended header for that specific content meta type.
/// NcmPackagedContentInfo and/or NcmContentMetaInfo entries may follow afterwards.
/// If the extended data size field from the extended header (if available) is non-zero, this data is saved after the content info entries.
/// Finally, a 0x20 byte long digest is appended to the EOF.
typedef struct {
    u64 title_id;
    ContentMetaVersion version;
    u8 content_meta_type;                                   ///< NcmContentMetaType.
    u8 reserved_1;
    u16 extended_header_size;                               ///< Must match the size from the extended header struct for this content meta type (SystemUpdate, Application, Patch, AddOnContent, Delta).
    u16 content_count;                                      ///< Determines how many NcmPackagedContentInfo entries are available after the extended header.
    u16 content_meta_count;                                 ///< Determines how many NcmContentMetaInfo entries are available after the NcmPackagedContentInfo entries. Only used for SystemUpdate.
    u8 content_meta_attribute;                              ///< ContentMetaAttribute.
    u8 storage_id;                                          ///< NcmStorageId.
    u8 content_install_type;                                ///< NcmContentInstallType.
    ContentMetaInstallState install_state;
    ContentMetaVersion required_download_system_version;
    u8 reserved_2[0x4];
} ContentMetaPackagedHeader;

/// Extended header for the SystemUpdate title.
/// Equivalent to NcmSystemUpdateMetaExtendedHeader.
typedef struct {
    u32 extended_data_size;
} ContentMetaSystemUpdateMetaExtendedHeader;

/// Extended header for Application titles.
/// Equivalent to NcmApplicationMetaExtendedHeader, but using ContentMetaVersion structs.
typedef struct {
    u64 patch_id;
    ContentMetaVersion required_system_version;
    ContentMetaVersion required_application_version;
} ContentMetaApplicationMetaExtendedHeader;

/// Extended header for Patch titles.
/// Equivalent to NcmPatchMetaExtendedHeader, but using a ContentMetaVersion struct.
typedef struct {
    u64 application_id;
    ContentMetaVersion required_system_version;
    u32 extended_data_size;
    u8 reserved[0x8];
} ContentMetaPatchMetaExtendedHeader;

/// Extended header for AddOnContent titles.
/// Equivalent to NcmAddOnContentMetaExtendedHeader, but using a ContentMetaVersion struct.
typedef struct {
    u64 application_id;
    ContentMetaVersion required_application_version;
    u8 reserved[0x4];
} ContentMetaAddOnContentMetaExtendedHeader;

/// Extended header for Delta titles.
typedef struct {
    u64 application_id;
    u32 extended_data_size;
    u8 reserved[0x4];
} ContentMetaDeltaMetaExtendedHeader;

typedef enum {
    ContentMetaFirmwareVariationVersion_Invalid = 0,
    ContentMetaFirmwareVariationVersion_V1      = 1,
    ContentMetaFirmwareVariationVersion_V2      = 2,
    ContentMetaFirmwareVariationVersion_Unknown = 3
} ContentMetaFirmwareVariationVersion;

/// Header for the extended data region in the SystemUpdate title, pointed to by the extended header.
/// If version is ContentMetaFirmwareVariationVersion_V1, this is followed by 'variation_count' ContentMetaFirmwareVariationInfoV1 entries.
/// Otherwise, if version is ContentMetaFirmwareVariationVersion_V2, this is followed by:
///     * 'variation_count' firmware variation IDs.
///     * 'variation_count' ContentMetaFirmwareVariationInfoV2 entries.
///     * (Optionally) A variable number of NcmContentMetaInfo entries, which is the sum of all 'meta_count' values from ContentMetaFirmwareVariationInfoV2 entries where 'refer_to_base' is set to false.
typedef struct {
    u32 version;            ///< ContentMetaFirmwareVariationVersion.
    u32 variation_count;    ///< Determines how many firmware variation entries are available after this header.
} ContentMetaSystemUpdateMetaExtendedDataHeader;

/// Used if the firmware variation version matches ContentMetaFirmwareVariationVersion_V1.
typedef struct {
    u32 firmware_variation_id;
    u8 reserved[0x1C];
} ContentMetaFirmwareVariationInfoV1;

/// Used if the firmware variation version matches ContentMetaFirmwareVariationVersion_V2.
typedef struct {
    bool refer_to_base;
    u8 reserved_1[0x3];
    u32 meta_count;
    u8 reserved_2[0x18];
} ContentMetaFirmwareVariationInfoV2;

/// Header for the extended data region in Patch titles, pointed to by the extended header.
/// This is followed by:
///     * 'history_count' ContentMetaPatchHistoryHeader entries.
///     * 'delta_history_count' ContentMetaPatchDeltaHistory entries.
///     * 'delta_count' ContentMetaPatchDeltaHeader entries.
///     * 'fragment_set_count' ContentMetaFragmentSet entries.
///     * 'history_content_count' NcmContentInfo entries.
///     * 'delta_content_count' NcmPackagedContentInfo entries.
///     * A variable number of ContentMetaFragmentIndicator entries, which is the sum of all 'fragment_count' values from ContentMetaFragmentSet entries.
typedef struct {
    u32 history_count;
    u32 delta_history_count;
    u32 delta_count;
    u32 fragment_set_count;
    u32 history_content_count;
    u32 delta_content_count;
    u8 reserved[0x4];
} ContentMetaPatchMetaExtendedDataHeader;

typedef struct {
    NcmContentMetaKey content_meta_key;
    u8 digest[CNMT_DIGEST_SIZE];
    u16 content_info_count;
    u8 reserved[0x6];
} ContentMetaPatchHistoryHeader;

typedef struct {
    u64 source_patch_id;
    u64 destination_patch_id;
    ContentMetaVersion source_version;
    ContentMetaVersion destination_version;
    u64 download_size;
    u8 reserved[0x8];
} ContentMetaPatchDeltaHistory;

typedef struct {
    u64 source_patch_id;
    u64 destination_patch_id;
    ContentMetaVersion source_version;
    ContentMetaVersion destination_version;
    u16 fragment_set_count;
    u8 reserved_1[0x6];
    u16 content_info_count;
    u8 reserved_2[0x6];
} ContentMetaPatchDeltaHeader;

typedef enum {
    ContentMetaUpdateType_ApplyAsDelta = 0,
    ContentMetaUpdateType_Overwrite    = 1,
    ContentMetaUpdateType_Create       = 2
} ContentMetaUpdateType;

typedef struct {
    NcmContentId source_content_id;
    NcmContentId destination_content_id;
    u32 source_size_low;
    u16 source_size_high;
    u32 destination_size_low;
    u16 destination_size_high;
    u16 fragment_count;
    NcmContentType fragment_target_content_type;
    u8 update_type;                                 ///< ContentMetaUpdateType.
    u8 reserved[0x4];
} ContentMetaFragmentSet;

typedef struct {
    u16 content_info_index;
    u16 fragment_index;
} ContentMetaFragmentIndicator;

/// Header for the extended data region in Delta titles, pointed to by the extended header.
/// This is followed by:
///     * 'fragment_set_count' ContentMetaFragmentSet entries.
///     * A variable number of ContentMetaFragmentIndicator entries, which is the sum of all 'fragment_count' values from ContentMetaFragmentSet entries.
typedef struct {
    u64 source_patch_id;
    u64 destination_patch_id;
    ContentMetaVersion source_version;
    ContentMetaVersion destination_version;
    u16 fragment_set_count;
    u8 reserved[0x6];
} ContentMetaDeltaMetaExtendedDataHeader;

typedef struct {
    NcaContext *nca_ctx;                            ///< Pointer to the NCA context for the Meta NCA from which CNMT data is retrieved.
    PartitionFileSystemContext pfs_ctx;             ///< PartitionFileSystemContext for the Meta NCA FS section #0, which is where the CNMT is stored.
    PartitionFileSystemEntry *pfs_entry;            ///< PartitionFileSystemEntry for the CNMT in the Meta NCA FS section #0. Used to generate a NcaHierarchicalSha256Patch if needed.
    NcaHierarchicalSha256Patch nca_patch;           ///< NcaHierarchicalSha256Patch generated if CNMT modifications are needed. Used to seamlessly replace Meta NCA data while writing it.
                                                    ///< Bear in mind that generating a patch modifies the NCA context.
    char *cnmt_filename;                            ///< Pointer to the CNMT filename in the Meta NCA FS section #0.
    u8 *raw_data;                                   ///< Pointer to a dynamically allocated buffer that holds the raw CNMT.
    u64 raw_data_size;                              ///< Raw CNMT size.
    ContentMetaPackagedHeader *packaged_header;     ///< Pointer to the ContentMetaPackagedHeader within 'raw_data'.
    u8 *extended_header;                            ///< Pointer to the extended header within 'raw_data', if available. May be casted to other types. Its size is stored in 'packaged_header'.
    NcmPackagedContentInfo *packaged_content_info;  ///< Pointer to the NcmPackagedContentInfo entries within 'raw_data'. The content count is stored in 'packaged_header'.
    NcmContentMetaInfo *content_meta_info;          ///< Pointer to the NcmContentMetaInfo entries within 'raw_data', if available. The content meta count is stored in 'packaged_header'.
    u8 *extended_data;                              ///< Pointer to the extended data block within 'raw_data', if available.
    u32 extended_data_size;                         ///< Size of the extended data block within 'raw_data', if available. Kept here for convenience - this is part of the header in 'extended_data'.
    u8 *digest;                                     ///< Pointer to the digest within 'raw_data'.
} ContentMetaContext;

/// Initializes a ContentMetaContext using a previously initialized NcaContext (which must belong to a Meta NCA).
bool cnmtInitializeContext(ContentMetaContext *out, NcaContext *nca_ctx);

/// Helper inline functions.

NX_INLINE void cnmtFreeContext(ContentMetaContext *cnmt_ctx)
{
    if (!cnmt_ctx) return;
    pfsFreeContext(&(cnmt_ctx->pfs_ctx));
    pfsFreeEntryPatch(&(cnmt_ctx->nca_patch));
    if (cnmt_ctx->raw_data) free(cnmt_ctx->raw_data);
    memset(cnmt_ctx, 0, sizeof(ContentMetaContext));
}

#endif /* __CNMT_H__ */