/*
 * Copyright (c) 2000-2001 Apple Computer, Inc. All Rights Reserved.
 * 
 * The contents of this file constitute Original Code as defined in and are
 * subject to the Apple Public Source License Version 1.2 (the 'License').
 * You may not use this file except in compliance with the License. Please obtain
 * a copy of the License at http://www.apple.com/publicsource and read it before
 * using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS
 * OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, INCLUDING WITHOUT
 * LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
 * PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see the License for the
 * specific language governing rights and limitations under the License.
 */


//
//  AppleDatabase.h - Description t.b.d.
//
#ifndef _H_APPLEDATABASE
#define _H_APPLEDATABASE

#include "MetaRecord.h"
#include "SelectionPredicate.h"
#include "DbIndex.h"

#include <Security/AtomicFile.h>
#include <Security/Database.h>
#include <Security/DbContext.h>
#include <Security/handleobject.h>
#include <Security/refcount.h>
#include <memory>
#include <vector>

namespace Security
{

// Abstract database Cursor class.
class Cursor;
class DbVersion;
class CssmAutoQuery;

struct AppleDatabaseTableName
{
	uint32 mTableId;
	const char *mTableName;
	
	// indices of meta-table entries in an array of table names

	enum {
		kSchemaInfo = 0,
		kSchemaAttributes,
		kSchemaIndexes,
		kSchemaParsingModule,
		kNumRequiredTableNames
	};
};

//
// This is what the CDSA standard refers to as a Relation.  We use
// the more conventional term Table.
//
class Table
{
	NOCOPY(Table)
public:
	// Type used to refer to a table.
	typedef CSSM_DB_RECORDTYPE Id;

    Table(const ReadSection &inTableSection);
	~Table();
#if 0
    Table(const CSSM_DB_RECORD_ATTRIBUTE_INFO &inInfo) :
		mMetaRecord (inInfo) {}
    Table(Id inTableId, const string &inTableName,
		  uint32 inNumberOfAttributes,
		  const CSSM_DB_SCHEMA_ATTRIBUTE_INFO *inAttributeInfo,
		  uint32 inNumberOfIndexes, 
		  const CSSM_DB_SCHEMA_INDEX_INFO *inIndexInfo) :
		mMetaRecord(inTableId, inTableName,
				    inNumberOfAttributes, inAttributeInfo)
		{ /* XXX Use inIndexInfo */ }
#endif

	// Return a newly created cursor satisfying inQuery on the receiving table
	// The returned Cursor may or may not use indexes depending on their availability.
	Cursor *createCursor(const CSSM_QUERY *inQuery, const DbVersion &inDbVersion) const;

	const ReadSection getRecordSection(uint32 inRecordNumber) const;

	const RecordId getRecord(const RecordId &inRecordId,
							 CSSM_DB_RECORD_ATTRIBUTE_DATA_PTR inoutAttributes,
							 CssmData *inoutData,
							 CssmAllocator &inAllocator) const;

	// Return the number of recordNumbers in use by this table including empty slots.
    uint32 recordNumberCount() const { return mRecordNumbersCount; }
    uint32 freeListHead() const { return mFreeListHead; }

	// Return the record number corresponding to aFreeListHead and update
	// aFreeListHead to point to the next availble recordNumber slot.
	uint32 popFreeList(uint32 &aFreeListHead) const;

	MetaRecord &getMetaRecord() { return mMetaRecord; }
	const MetaRecord &getMetaRecord() const { return mMetaRecord; }

	uint32 getRecordsCount() const { return mRecordsCount; }
	const ReadSection getRecordsSection() const;
	
	const ReadSection &getTableSection() const { return mTableSection; }

	bool matchesTableId(Id inTableId) const;

	void readIndexSection();
	
	enum
	{
		OffsetSize					= AtomSize * 0,
		OffsetId					= AtomSize * 1,
		OffsetRecordsCount			= AtomSize * 2,
		OffsetRecords				= AtomSize * 3,
		OffsetIndexesOffset			= AtomSize * 4,
		OffsetFreeListHead			= AtomSize * 5,
		OffsetRecordNumbersCount	= AtomSize * 6,
		OffsetRecordNumbers			= AtomSize * 7
	};
protected:
	friend class ModifiedTable;
	
	MetaRecord mMetaRecord;
	const ReadSection mTableSection;

	uint32 mRecordsCount;
	uint32 mFreeListHead;
	// Number of record numbers (including freelist slots) in this table.
	uint32 mRecordNumbersCount;

	// all the table's indexes, mapped by index id
	typedef map<uint32, DbConstIndex *> ConstIndexMap;
	ConstIndexMap mIndexMap;
};

class ModifiedTable
{
	NOCOPY(ModifiedTable)
public:
	ModifiedTable(const Table *inTable);
	ModifiedTable(MetaRecord *inMetaRecord); // Take over ownership of inMetaRecord
	~ModifiedTable();

	// Mark the record with inRecordId as deleted.
    void deleteRecord(const RecordId &inRecordId);
    const RecordId insertRecord(AtomicFile::VersionId inVersionId,
								const CSSM_DB_RECORD_ATTRIBUTE_DATA *inAttributes,
								const CssmData *inData);
    const RecordId updateRecord(const RecordId &inRecordId,
								const CSSM_DB_RECORD_ATTRIBUTE_DATA *inAttributes,
								const CssmData *inData,
								CSSM_DB_MODIFY_MODE inModifyMode);

	// Return the MetaRecord this table should use for writes.
	const MetaRecord &getMetaRecord() const;

	// find, and create if needed, an index with the given id
	DbMutableIndex &findIndex(uint32 indexId, const MetaRecord &metaRecord, bool isUniqueIndex);

	// Write this table to inOutputFile at inSectionOffset and return the new offset.
    uint32 writeTable(AtomicFile &inOutputFile, uint32 inSectionOffset);

private:
	// Return the next available record number for this table.
    uint32 nextRecordNumber();

	// Return the number of recordNumbers in use by this table including empty slots.
    uint32 recordNumberCount() const;

	void modifyTable();
	void createMutableIndexes();
	uint32 writeIndexSection(WriteSection &tableSection, uint32 offset);

	// Optional, this is merly a reference, we do not own this object.
	const Table *mTable;
	
	// Optional, New MetaRecord.  This is only present if it is different from the
	// MetaRecord of mTable or mTable is nil.
	const MetaRecord *mNewMetaRecord;

	// Set of Records that have been deleted or modified.
    typedef set<uint32> DeletedSet;
    DeletedSet mDeletedSet;

	// Set of Records that have been inserted or modified.
    typedef map<uint32, WriteSection *> InsertedMap;
    InsertedMap mInsertedMap;

	// Next lowest available RecordNumber
    uint32 mRecordNumberCount;
	// Head of the free list (if there is one) or 0 if either we have no
	// mTable of the free list has been exhausted.
    uint32 mFreeListHead;
	
	// has this table actually been modified?
	bool mIsModified;

	typedef map<uint32, DbMutableIndex *> MutableIndexMap;
	MutableIndexMap mIndexMap;
};

//
// Read only snapshot of a database.
//
class Metadata
{
	NOCOPY(Metadata)
protected:
	Metadata() {}
    enum
    {
		HeaderOffset		= 0,	// Absolute offset of header.
		OffsetMagic			= AtomSize * 0,
		OffsetVersion		= AtomSize * 1,
		OffsetAuthOffset	= AtomSize * 2,
		OffsetSchemaOffset	= AtomSize * 3,
        HeaderSize			= AtomSize * 4,

        HeaderMagic			= FOUR_CHAR_CODE('kych'),
        HeaderVersion		= 0x00010000
    };

	enum
	{
		OffsetSchemaSize	= AtomSize * 0,
		OffsetTablesCount	= AtomSize * 1,
		OffsetTables		= AtomSize * 2
	};
};

//
// Read only representation of a database
//
class DbVersion : public Metadata, public RefCount
{
	NOCOPY(DbVersion)
public:
    DbVersion(AtomicFile &inDatabaseFile, const class AppleDatabase &db);
    ~DbVersion();

    // Return true if the file on which this DbVersion is based
	// has been modified.
    bool isDirty() const;

	AtomicFile::VersionId getVersionId() const { return mVersionId; }
	const RecordId getRecord(Table::Id inTableId, const RecordId &inRecordId,
							 CSSM_DB_RECORD_ATTRIBUTE_DATA *inoutAttributes,
							 CssmData *inoutData, CssmAllocator &inAllocator) const;
	Cursor *createCursor(const CSSM_QUERY *inQuery) const;
protected:
	const Table &findTable(Table::Id inTableId) const;
	Table &findTable(Table::Id inTableId);

private:
    void open(); // Part of constructor contract.

	ReadSection mDatabase;
	AtomicFile *mDatabaseFile;
    AtomicFile::VersionId mVersionId;

	friend class DbModifier; // XXX Fixme
    typedef map<Table::Id, Table *> TableMap;
    TableMap mTableMap;
	const class AppleDatabase &mDb;

public:
	typedef Table value_type;
	typedef const Table &const_reference;
	typedef const Table *const_pointer;

	// A const forward iterator.
	class const_iterator
	{
	public:
		const_iterator(const TableMap::const_iterator &it) : mIterator(it) {}

		// Use default copy consturctor and assignment operator.
		//const_iterator(const const_iterator &it) : mIterator(it.mIterator) {}
		//const_iterator &operator=(const const_iterator &it) { mIterator = it.mIterator; return *this; }
		const_reference operator*() const { return *mIterator->second; }
		const_iterator &operator++() { mIterator.operator++(); return *this; }
		const_iterator operator++(int i) { return const_iterator(mIterator.operator++(i)); }
		bool operator!=(const const_iterator &other) const { return mIterator != other.mIterator; }
		bool operator==(const const_iterator &other) const { return mIterator == other.mIterator; }

		const_pointer operator->() const { return mIterator->second; } // Not really needed.

	private:
		TableMap::const_iterator mIterator;
	};

	const_iterator begin() const { return const_iterator(mTableMap.begin()); }
	const_iterator end() const { return const_iterator(mTableMap.end()); }
};

//
// Cursor
//
class Cursor : public HandleObject
{
public:
    virtual ~Cursor();
    virtual bool next(Table::Id &outTableId,
					CSSM_DB_RECORD_ATTRIBUTE_DATA_PTR outAttributes,
					CssmData *outData,
					CssmAllocator &inAllocator,
					RecordId &recordId) = 0;
};

//
// LinearCursor
//
class LinearCursor : public Cursor
{
    NOCOPY(LinearCursor)
public:
    LinearCursor(const CSSM_QUERY *inQuery, const DbVersion &inDbVersion,
		   const Table &inTable);
    virtual ~LinearCursor();
    virtual bool next(Table::Id &outTableId,
					CSSM_DB_RECORD_ATTRIBUTE_DATA_PTR outAttributes,
					CssmData *outData,
					CssmAllocator &inAllocator,
					RecordId &recordId);
					
private:
	const RefPointer<const DbVersion> mDbVersion;
	uint32 mRecordsCount;
    uint32 mRecord;
	const ReadSection mRecordsSection;
	uint32 mReadOffset;
    const MetaRecord &mMetaRecord;

    CSSM_DB_CONJUNCTIVE mConjunctive;
    CSSM_QUERY_FLAGS mQueryFlags; // If CSSM_QUERY_RETURN_DATA is set return the raw key bits;
    typedef vector<SelectionPredicate *> PredicateVector;

    PredicateVector mPredicates;
};

//
// A cursor that uses an index.
//

class IndexCursor : public Cursor
{
	NOCOPY(IndexCursor)
public:
	IndexCursor(DbQueryKey *queryKey, const DbVersion &inDbVersion,
		const Table &table, const DbConstIndex *index);
	virtual ~IndexCursor();

    virtual bool next(Table::Id &outTableId,
					CSSM_DB_RECORD_ATTRIBUTE_DATA_PTR outAttributes,
					CssmData *outData,
					CssmAllocator &inAllocator,
					RecordId &recordId);

private:
	auto_ptr<DbQueryKey> mQueryKey;
	const DbVersion &mDbVersion;
	const Table &mTable;
	const DbConstIndex *mIndex;
	
	DbIndexIterator mBegin, mEnd;
};

//
// MultiCursor
//
class MultiCursor : public Cursor
{
    NOCOPY(MultiCursor)
public:
    MultiCursor(const CSSM_QUERY *inQuery, const DbVersion &inDbVersion);
    virtual ~MultiCursor();
    virtual bool next(Table::Id &outTableId,
					CSSM_DB_RECORD_ATTRIBUTE_DATA_PTR outAttributes,
					CssmData *outData,
					CssmAllocator &inAllocator,
					RecordId &recordId);
private:
	const RefPointer<const DbVersion> mDbVersion;
	auto_ptr<CssmAutoQuery> mQuery;

	DbVersion::const_iterator mTableIterator;
	auto_ptr<Cursor> mCursor;
};

//
// A DbModifier contains all pending changes to be made to a DB.
// It also contains a DbVersion representing the state of the Database before any such changes
// No read-style operations are supported by DbModifier.  If a DbModifier exists for a
// particular Database and a client wishes to perform a query commit() must be called and
// the client should perform the new query on the current database version after the commit.
// Otherwise a client will not see changes made since the DbModifier was instanciated.
//
class DbModifier : public Metadata
{
	NOCOPY(DbModifier)
public:
    DbModifier(AtomicFile &inAtomicFile, const class AppleDatabase &db);
    ~DbModifier();

	// Whole database affecting members.
    void createDatabase(const CSSM_DBINFO &inDbInfo,
						const CSSM_ACL_ENTRY_INPUT *inInitialAclEntry);
	void openDatabase(); // This is optional right now.
	void closeDatabase();
	void deleteDatabase();

    void commit();
    void rollback();

	// Record changing members
	void deleteRecord(Table::Id inTableId, const RecordId &inRecordId);
	const RecordId insertRecord(Table::Id inTableId,
								const CSSM_DB_RECORD_ATTRIBUTE_DATA *inAttributes,
								const CssmData *inData);
	const RecordId updateRecord(Table::Id inTableId, const RecordId &inRecordId,
								const CSSM_DB_RECORD_ATTRIBUTE_DATA *inAttributes,
								const CssmData *inData,
								CSSM_DB_MODIFY_MODE inModifyMode);

	// Schema changing members
    void insertTable(Table::Id inTableId, const string &inTableName,
					 uint32 inNumberOfAttributes,
					 const CSSM_DB_SCHEMA_ATTRIBUTE_INFO *inAttributeInfo,
					 uint32 inNumberOfIndexes,
					 const CSSM_DB_SCHEMA_INDEX_INFO *inIndexInfo);
	void deleteTable(Table::Id inTableId);

	// Record reading members
	const RecordId getRecord(Table::Id inTableId, const RecordId &inRecordId,
							 CSSM_DB_RECORD_ATTRIBUTE_DATA *inoutAttributes,
							 CssmData *inoutData, CssmAllocator &inAllocator);
	Cursor *createCursor(const CSSM_QUERY *inQuery);
protected:
    void modifyDatabase();
    const RefPointer<const DbVersion> getDbVersion();

    ModifiedTable *createTable(MetaRecord *inMetaRecord); // Takes over ownership of inMetaRecord
	
	void insertTableSchema(const CssmDbRecordAttributeInfo &inInfo,
		const CSSM_DB_RECORD_INDEX_INFO *inIndexInfo = NULL);
		
	void insertTable(const CssmDbRecordAttributeInfo &inInfo,
		const CSSM_DB_RECORD_INDEX_INFO * inIndexInfo = NULL,
		const CSSM_DB_PARSING_MODULE_INFO * inParsingModule = NULL);

    ModifiedTable &findTable(Table::Id inTableId);

    uint32 writeAuthSection(uint32 inSectionOffset);
    uint32 writeSchemaSection(uint32 inSectionOffset);

private:
	
	// Current DbVersion of this database before any changes we are going to make.
	RefPointer<const DbVersion> mDbVersion;
	Mutex mDbVersionLock;

    AtomicFile &mAtomicFile;
    AtomicFile::VersionId mVersionId;
    AtomicFile::FileRef mFileRef;
    bool mWriting;

    typedef map<Table::Id, ModifiedTable *> ModifiedTableMap;
    ModifiedTableMap mModifiedTableMap;
	
	const class AppleDatabase &mDb;
};

//
// AppleDatabaseManager
//
class AppleDatabaseManager : public DatabaseManager
{
public:
	AppleDatabaseManager(const AppleDatabaseTableName *tableNames);
    Database *make(const DbName &inDbName);
	
protected:
	const AppleDatabaseTableName *mTableNames;
};

//
// AppleDbContext
//
class AppleDbContext : public DbContext
{
public:
	AppleDbContext(Database &inDatabase,
				   DatabaseSession &inDatabaseSession,
				   CSSM_DB_ACCESS_TYPE inAccessRequest,
				   const AccessCredentials *inAccessCred,
				   const void *inOpenParameters);
	virtual ~AppleDbContext();
	bool autoCommit() const { return mAutoCommit; }
	void autoCommit(bool on) { mAutoCommit = on; }
	
private:
	bool mAutoCommit;
};

//
// AppleDatabase
//
class AppleDatabase : public Database
{
public:
    AppleDatabase(const DbName &inDbName, const AppleDatabaseTableName *tableNames);
    virtual ~AppleDatabase();

    virtual void
        dbCreate(DbContext &inDbContext, const CSSM_DBINFO &inDBInfo,
                 const CSSM_ACL_ENTRY_INPUT *inInitialAclEntry);

    virtual void
        dbOpen(DbContext &inDbContext);

    virtual void
        dbClose();

    virtual void
        dbDelete(DatabaseSession &inDatabaseSession,
                 const AccessCredentials *inAccessCred);

    virtual void
        createRelation(DbContext &inDbContext,
                       CSSM_DB_RECORDTYPE inRelationID,
                       const char *inRelationName,
                       uint32 inNumberOfAttributes,
                       const CSSM_DB_SCHEMA_ATTRIBUTE_INFO &inAttributeInfo,
                       uint32 inNumberOfIndexes,
                       const CSSM_DB_SCHEMA_INDEX_INFO &inIndexInfo);

    virtual void
        destroyRelation(DbContext &inDbContext,
                        CSSM_DB_RECORDTYPE inRelationID);

    virtual void
        authenticate(DbContext &inDbContext,
                     CSSM_DB_ACCESS_TYPE inAccessRequest,
                     const AccessCredentials &inAccessCred);

    virtual void
        getDbAcl(DbContext &inDbContext,
                 const CSSM_STRING *inSelectionTag,
                 uint32 &outNumberOfAclInfos,
                 CSSM_ACL_ENTRY_INFO_PTR &outAclInfos);

    virtual void
        changeDbAcl(DbContext &inDbContext,
                    const AccessCredentials &inAccessCred,
                    const CSSM_ACL_EDIT &inAclEdit);

    virtual void
        getDbOwner(DbContext &inDbContext, CSSM_ACL_OWNER_PROTOTYPE &outOwner);

    virtual void
        changeDbOwner(DbContext &inDbContext,
                      const AccessCredentials &inAccessCred,
                      const CSSM_ACL_OWNER_PROTOTYPE &inNewOwner);

    virtual char *
        getDbNameFromHandle(const DbContext &inDbContext) const;

    virtual CSSM_DB_UNIQUE_RECORD_PTR
        dataInsert(DbContext &inDbContext,
                   CSSM_DB_RECORDTYPE RecordType,
                   const CSSM_DB_RECORD_ATTRIBUTE_DATA *inAttributes,
                   const CssmData *inData);

    virtual void
        dataDelete(DbContext &inDbContext,
                   const CSSM_DB_UNIQUE_RECORD &inUniqueRecordIdentifier);

    virtual void
        dataModify(DbContext &inDbContext,
                   CSSM_DB_RECORDTYPE inRecordType,
                   CSSM_DB_UNIQUE_RECORD &inoutUniqueRecordIdentifier,
                   const CSSM_DB_RECORD_ATTRIBUTE_DATA *inAttributesToBeModified,
                   const CssmData *inDataToBeModified,
                   CSSM_DB_MODIFY_MODE inModifyMode);

    virtual CSSM_HANDLE
        dataGetFirst(DbContext &inDbContext,
                     const DLQuery *inQuery,
                     CSSM_DB_RECORD_ATTRIBUTE_DATA_PTR inoutAttributes,
                     CssmData *inoutData,
                     CSSM_DB_UNIQUE_RECORD_PTR &outUniqueRecord);

    virtual bool
        dataGetNext(DbContext &inDbContext,
                    CSSM_HANDLE inResultsHandle,
                    CSSM_DB_RECORD_ATTRIBUTE_DATA_PTR inoutAttributes,
                    CssmData *inoutData,
                    CSSM_DB_UNIQUE_RECORD_PTR &outUniqueRecord);

    virtual void
        dataAbortQuery(DbContext &inDbContext,
                       CSSM_HANDLE inResultsHandle);

    virtual void
        dataGetFromUniqueRecordId(DbContext &inDbContext,
                                  const CSSM_DB_UNIQUE_RECORD &inUniqueRecord,
                                  CSSM_DB_RECORD_ATTRIBUTE_DATA_PTR inoutAttributes,
                                  CssmData *inoutData);

    virtual void
        freeUniqueRecord(DbContext &inDbContext,
                         CSSM_DB_UNIQUE_RECORD &inUniqueRecord);
						 
	virtual void passThrough(DbContext &dbContext,
							 uint32 passThroughId,
							 const void *inputParams,
							 void **outputParams);

    // Subclasses must implement this method.
    virtual DbContext *makeDbContext(DatabaseSession &inDatabaseSession,
                                     CSSM_DB_ACCESS_TYPE inAccessRequest,
                                     const AccessCredentials *inAccessCred,
                                     const void *inOpenParameters);
									 
	const CssmDbRecordAttributeInfo schemaRelations;
	const CssmDbRecordAttributeInfo schemaAttributes;
	const CssmDbRecordAttributeInfo schemaIndexes;
	const CssmDbRecordAttributeInfo schemaParsingModule;

	const char *recordName(CSSM_DB_RECORDTYPE inRecordType) const;

private:
	static void
	AppleDatabase::updateUniqueRecord(DbContext &inDbContext,
									CSSM_DB_RECORDTYPE inTableId,
									const RecordId &inRecordId,
									CSSM_DB_UNIQUE_RECORD &inoutUniqueRecord);

	CSSM_DB_UNIQUE_RECORD_PTR
	createUniqueRecord(DbContext &inDbContext, CSSM_DB_RECORDTYPE inTableId,
					   const RecordId &inRecordId);
	const RecordId parseUniqueRecord(const CSSM_DB_UNIQUE_RECORD &inUniqueRecord,
									 CSSM_DB_RECORDTYPE &outTableId);

    Mutex mWriteLock;
    AtomicFile mAtomicFile;
	DbModifier mDbModifier;
	const AppleDatabaseTableName *mTableNames;
};

} // end namespace Security

#endif //_H_APPLEDATABASE