// Copyright 2020 BitBank Software, Inc. All Rights Reserved.
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//    http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//===========================================================================

#ifndef __ANIMATEDGIF__
#define __ANIMATEDGIF__

#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define memcpy_P memcpy
#define PROGMEM

//
// GIF Animator
// Written by Larry Bank
// Copyright (c) 2020 BitBank Software, Inc.
// bitbank@pobox.com
//
// Designed to decode images up to 480x320
// using less than 22K of RAM
//

/* GIF Defines and variables */
#define MAX_CHUNK_SIZE 255
//
// These 2 macros can be changed to limit the amount of RAM
// required by the decoder. For example, decoding 1-bit images to
// a 128x32 display will not need a max code size of 12 nor a palette
// with 256 entries
//
#define MAX_CODE_SIZE 12
#define MAX_COLORS    256
#define LZW_BUF_SIZE  (6 * MAX_CHUNK_SIZE)
#define LZW_HIGHWATER (4 * MAX_CHUNK_SIZE)
#ifdef __LINUX__
#define MAX_WIDTH 2048
#else
#define MAX_WIDTH 320
#endif // __LINUX__
// This buffer is used to store the pixel sequence in reverse order
// it needs to be large enough to hold the longest possible
// sequence (1<<MAX_CODE_SIZE)
#define FILE_BUF_SIZE (1 << MAX_CODE_SIZE)

#define PIXEL_FIRST 0
#define PIXEL_LAST  (1 << MAX_CODE_SIZE)
#define LINK_UNUSED 5911 // 0x1717 to use memset
#define LINK_END    5912
#define MAX_HASH    5003

enum {
    GIF_PALETTE_RGB565_LE = 0, // little endian (default)
    GIF_PALETTE_RGB565_BE,     // big endian
    GIF_PALETTE_RGB888         // original 24-bpp entries
};
// for compatibility with older code
#define LITTLE_ENDIAN_PIXELS GIF_PALETTE_RGB565_LE
#define BIG_ENDIAN_PIXELS    GIF_PALETTE_RGB565_BE
//
// Draw callback pixel type
// RAW = 8-bit palettized pixels requiring transparent pixel handling
// COOKED = 16 or 24-bpp fully rendered pixels ready for display
//
enum { GIF_DRAW_RAW = 0, GIF_DRAW_COOKED };

enum {
    GIF_SUCCESS = 0,
    GIF_DECODE_ERROR,
    GIF_TOO_WIDE,
    GIF_INVALID_PARAMETER,
    GIF_UNSUPPORTED_FEATURE,
    GIF_FILE_NOT_OPEN,
    GIF_EARLY_EOF,
    GIF_EMPTY_FRAME,
    GIF_BAD_FILE,
    GIF_ERROR_MEMORY
};

typedef struct gif_file_tag {
    int32_t iPos;   // current file position
    int32_t iSize;  // file size
    uint8_t* pData; // memory file pointer
    void* fHandle;  // class pointer to File/SdFat or whatever you want
} GIFFILE;

typedef struct gif_info_tag {
    int32_t iFrameCount; // total frames in file
    int32_t iDuration;   // duration of animation in milliseconds
    int32_t iMaxDelay;   // maximum frame delay
    int32_t iMinDelay;   // minimum frame delay
} GIFINFO;

typedef struct gif_draw_tag {
    int iX, iY;                // Corner offset of this frame on the canvas
    int y;                     // current line being drawn (0 = top line of image)
    int iWidth, iHeight;       // size of this frame
    void* pUser;               // user supplied pointer
    uint8_t* pPixels;          // 8-bit source pixels for this line
    uint16_t* pPalette;        // little or big-endian RGB565 palette entries (default)
    uint8_t* pPalette24;       // RGB888 palette (optional)
    uint8_t ucTransparent;     // transparent color
    uint8_t ucHasTransparency; // flag indicating the transparent color is in use
    uint8_t ucDisposalMethod;  // frame disposal method
    uint8_t ucBackground;      // background color
    uint8_t ucIsGlobalPalette; // Flag to indicate that a global palette, rather than a local palette is being used
} GIFDRAW;

// Callback function prototypes
typedef int32_t(GIF_READ_CALLBACK)(GIFFILE* pFile, uint8_t* pBuf, int32_t iLen);
typedef int32_t(GIF_SEEK_CALLBACK)(GIFFILE* pFile, int32_t iPosition);
typedef void(GIF_DRAW_CALLBACK)(GIFDRAW* pDraw);
typedef void*(GIF_OPEN_CALLBACK)(const char* szFilename, int32_t* pFileSize);
typedef void(GIF_CLOSE_CALLBACK)(void* pHandle);
typedef void*(GIF_ALLOC_CALLBACK)(uint32_t iSize);
typedef void(GIF_FREE_CALLBACK)(void* buffer);
//
// our private structure to hold a GIF image decode state
//
typedef struct gif_image_tag {
    int iWidth, iHeight, iCanvasWidth, iCanvasHeight;
    int iX, iY; // GIF corner offset
    int iBpp;
    int iError;           // last error
    int iFrameDelay;      // delay in milliseconds for this frame
    int iRepeatCount;     // NETSCAPE animation repeat count. 0=forever
    int iXCount, iYCount; // decoding position in image (countdown values)
    int iLZWOff;          // current LZW data offset
    int iLZWSize;         // current quantity of data in the LZW buffer
    int iCommentPos;      // file offset of start of comment data
    short sCommentLen;    // length of comment
    GIF_READ_CALLBACK* pfnRead;
    GIF_SEEK_CALLBACK* pfnSeek;
    GIF_DRAW_CALLBACK* pfnDraw;
    GIF_OPEN_CALLBACK* pfnOpen;
    GIF_CLOSE_CALLBACK* pfnClose;
    GIFFILE GIFFile;
    void* pUser;
    unsigned char* pFrameBuffer;
    unsigned char *pPixels, *pOldPixels;
    unsigned char ucLineBuf[MAX_WIDTH];                 // current line
    unsigned char ucFileBuf[FILE_BUF_SIZE];             // holds temp data and pixel stack
    unsigned short pPalette[(MAX_COLORS * 3) / 2];      // can hold RGB565 or RGB888 - set in begin()
    unsigned short pLocalPalette[(MAX_COLORS * 3) / 2]; // color palettes for GIF images
    unsigned char ucLZW[LZW_BUF_SIZE];                  // holds 6 chunks (6x255) of GIF LZW data packed together
    unsigned short usGIFTable[1 << MAX_CODE_SIZE];
    unsigned char ucGIFPixels[(PIXEL_LAST * 2)];
    unsigned char bEndOfFrame;
    unsigned char ucGIFBits, ucBackground, ucTransparent, ucCodeStart, ucMap, bUseLocalPalette;
    unsigned char ucPaletteType; // RGB565 or RGB888
    unsigned char ucDrawType;    // RAW or COOKED
} GIFIMAGE;

#ifdef __cplusplus
//
// The GIF class wraps portable C code which does the actual work
//
class AnimatedGIF {
  public:
    int open(uint8_t* pData, int iDataSize, GIF_DRAW_CALLBACK* pfnDraw);
    int openFLASH(uint8_t* pData, int iDataSize, GIF_DRAW_CALLBACK* pfnDraw);
    int open(const char* szFilename,
             GIF_OPEN_CALLBACK* pfnOpen,
             GIF_CLOSE_CALLBACK* pfnClose,
             GIF_READ_CALLBACK* pfnRead,
             GIF_SEEK_CALLBACK* pfnSeek,
             GIF_DRAW_CALLBACK* pfnDraw);
    void close();
    void reset();
    void begin(unsigned char ucPaletteType = GIF_PALETTE_RGB565_LE);
    void begin(int iEndian, unsigned char ucPaletteType) {
        begin(ucPaletteType);
    };
    int playFrame(bool bSync, int* delayMilliseconds, void* pUser = NULL);
    int getCanvasWidth();
    int allocFrameBuf(GIF_ALLOC_CALLBACK* pfnAlloc);
    int setDrawType(int iType);
    int freeFrameBuf(GIF_FREE_CALLBACK* pfnFree);
    uint8_t* getFrameBuf();
    int getCanvasHeight();
    int getLoopCount();
    int getInfo(GIFINFO* pInfo);
    int getLastError();
    int getComment(char* destBuffer);

  private:
    GIFIMAGE _gif;
};
#else
// C interface
int GIF_openRAM(GIFIMAGE* pGIF, uint8_t* pData, int iDataSize, GIF_DRAW_CALLBACK* pfnDraw);
int GIF_openFile(GIFIMAGE* pGIF, const char* szFilename, GIF_DRAW_CALLBACK* pfnDraw);
void GIF_close(GIFIMAGE* pGIF);
void GIF_begin(GIFIMAGE* pGIF, unsigned char ucPaletteType);
void GIF_reset(GIFIMAGE* pGIF);
int GIF_playFrame(GIFIMAGE* pGIF, int* delayMilliseconds, void* pUser);
int GIF_getCanvasWidth(GIFIMAGE* pGIF);
int GIF_getCanvasHeight(GIFIMAGE* pGIF);
int GIF_getComment(GIFIMAGE* pGIF, char* destBuffer);
int GIF_getInfo(GIFIMAGE* pGIF, GIFINFO* pInfo);
int GIF_getLastError(GIFIMAGE* pGIF);
int GIF_getLoopCount(GIFIMAGE* pGIF);
#endif // __cplusplus

// Due to unaligned memory causing an exception, we have to do these macros the slow way
#define INTELSHORT(p) ((*p) + (*(p + 1) << 8))
#define INTELLONG(p)  ((*p) + (*(p + 1) << 8) + (*(p + 2) << 16) + (*(p + 3) << 24))
#define MOTOSHORT(p)  (((*(p)) << 8) + (*(p + 1)))
#define MOTOLONG(p)   (((*p) << 24) + ((*(p + 1)) << 16) + ((*(p + 2)) << 8) + (*(p + 3)))

// Must be a 32-bit target processor
#define REGISTER_WIDTH 32

#endif // __ANIMATEDGIF__