//===----------------------------------------------------------------------===//
//                         DuckDB
//
// duckdb/storage/checkpoint/string_checkpoint_state.hpp
//
//
//===----------------------------------------------------------------------===//

#pragma once

#include "duckdb/common/common.hpp"
#include "duckdb/storage/storage_info.hpp"
#include "duckdb/storage/buffer/block_handle.hpp"
#include "duckdb/function/compression_function.hpp"

namespace duckdb {

class OverflowStringWriter {
public:
	virtual ~OverflowStringWriter() {
	}

	virtual void WriteString(string_t string, block_id_t &result_block, int32_t &result_offset) = 0;
};

struct StringBlock {
	shared_ptr<BlockHandle> block;
	idx_t offset;
	idx_t size;
	unique_ptr<StringBlock> next;
};

struct string_location_t {
	string_location_t(block_id_t block_id, int32_t offset) : block_id(block_id), offset(offset) {
	}
	string_location_t() {
	}
	bool IsValid() {
		return offset < Storage::BLOCK_SIZE && (block_id == INVALID_BLOCK || block_id >= MAXIMUM_BLOCK);
	}
	block_id_t block_id;
	int32_t offset;
};

struct UncompressedStringSegmentState : public CompressedSegmentState {
	~UncompressedStringSegmentState();

	//! The string block holding strings that do not fit in the main block
	//! FIXME: this should be replaced by a heap that also allows freeing of unused strings
	unique_ptr<StringBlock> head;
	//! Overflow string writer (if any), if not set overflow strings will be written to memory blocks
	unique_ptr<OverflowStringWriter> overflow_writer;
	//! Map of block id to string block
	unordered_map<block_id_t, StringBlock *> overflow_blocks;
};

} // namespace duckdb