/**
 * XtcParser.h
 *
 * XTC file parsing and page data extraction
 * XTC ebook support for CrossPoint Reader
 */

#pragma once

#include <SdFat.h>

#include <functional>
#include <memory>
#include <string>
#include <vector>

#include "XtcTypes.h"

namespace xtc {

/**
 * XTC File Parser
 *
 * Reads XTC files from SD card and extracts page data.
 * Designed for ESP32-C3's limited RAM (~380KB) using streaming.
 */
class XtcParser {
 public:
  XtcParser();
  ~XtcParser();

  // File open/close
  XtcError open(const char* filepath);
  void close();
  bool isOpen() const { return m_isOpen; }

  // Header information access
  const XtcHeader& getHeader() const { return m_header; }
  uint16_t getPageCount() const { return m_header.pageCount; }
  uint16_t getWidth() const { return m_defaultWidth; }
  uint16_t getHeight() const { return m_defaultHeight; }
  uint8_t getBitDepth() const { return m_bitDepth; }  // 1 = XTC/XTG, 2 = XTCH/XTH

  // Page information
  bool getPageInfo(uint32_t pageIndex, PageInfo& info) const;

  /**
   * Load page bitmap (raw 1-bit data, skipping XTG header)
   *
   * @param pageIndex Page index (0-based)
   * @param buffer Output buffer (caller allocated)
   * @param bufferSize Buffer size
   * @return Number of bytes read on success, 0 on failure
   */
  size_t loadPage(uint32_t pageIndex, uint8_t* buffer, size_t bufferSize);

  /**
   * Streaming page load
   * Memory-efficient method that reads page data in chunks.
   *
   * @param pageIndex Page index
   * @param callback Callback function to receive data chunks
   * @param chunkSize Chunk size (default: 1024 bytes)
   * @return Error code
   */
  XtcError loadPageStreaming(uint32_t pageIndex,
                             std::function<void(const uint8_t* data, size_t size, size_t offset)> callback,
                             size_t chunkSize = 1024);

  // Get title from metadata
  std::string getTitle() const { return m_title; }

  bool hasChapters() const { return m_hasChapters; }
  const std::vector<ChapterInfo>& getChapters() const { return m_chapters; }

  // Validation
  static bool isValidXtcFile(const char* filepath);

  // Error information
  XtcError getLastError() const { return m_lastError; }

 private:
  FsFile m_file;
  bool m_isOpen;
  XtcHeader m_header;
  std::vector<PageInfo> m_pageTable;
  std::vector<ChapterInfo> m_chapters;
  std::string m_title;
  uint16_t m_defaultWidth;
  uint16_t m_defaultHeight;
  uint8_t m_bitDepth;  // 1 = XTC/XTG (1-bit), 2 = XTCH/XTH (2-bit)
  bool m_hasChapters;
  XtcError m_lastError;

  // Internal helper functions
  XtcError readHeader();
  XtcError readPageTable();
  XtcError readTitle();
  XtcError readChapters();
};

}  // namespace xtc