/*
    KindlePDFViewer: MuPDF abstraction for Lua
    Copyright (C) 2011 Hans-Werner Hilse <hilse@web.de>

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that 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/>.
*/
#include <fitz/fitz.h>

#include "blitbuffer.h"
#include "drawcontext.h"
#include "pdf.h"
#include <stdio.h>
#include <math.h>
#include <stddef.h>


typedef struct PdfDocument {
	fz_document *xref;
	fz_context *context;
} PdfDocument;

typedef struct PdfPage {
	int num;
#ifdef USE_DISPLAY_LIST
	fz_display_list *list;
#endif
	fz_page *page;
	PdfDocument *doc;
} PdfPage;


static double LOG_TRESHOLD_PERC = 0.05; // 5%

enum {
    MAGIC = 0x3795d42b,
};

typedef struct header {
    int magic;
    size_t sz;
} header;

static size_t msize=0;
static size_t msize_prev;
static size_t msize_max;
static size_t msize_min;
static size_t msize_iniz;
static int is_realloc=0;

char* readable_fs(double size/*in bytes*/, char *buf) {
    int i = 0;
    const char* units[] = {"B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"};
    while (size > 1024) {
        size /= 1024;
        i++;
    }
    sprintf(buf, "%.*f %s", i, size, units[i]);
    return buf;
}

static void resetMsize(){
	msize_iniz = msize;
	msize_prev = 0;
	msize_max = 0;
	msize_min = (size_t)-1;
}

static void showMsize(){
	char buf[15],buf2[15],buf3[15],buf4[15];
	printf("§§§ now: %s was: %s - min: %s - max: %s\n",readable_fs(msize,buf),readable_fs(msize_iniz,buf2),readable_fs(msize_min,buf3),readable_fs(msize_max,buf4));
	resetMsize();
}

static void log_size(char *funcName){
	if(msize_max < msize)
		msize_max = msize;
	if(msize_min > msize)
		msize_min = msize;
	if(1==0 && abs(msize-msize_prev)>msize_prev*LOG_TRESHOLD_PERC){
		char buf[15],buf2[15];
		printf("§§§ %s - total: %s (was %s)\n",funcName, readable_fs(msize,buf),readable_fs(msize_prev,buf2));
		msize_prev = msize;
	}
}

static void *
my_malloc_default(void *opaque, unsigned int size)
{
    struct header * h = malloc(size + sizeof(header));
    if (h == NULL)
         return NULL;

    h -> magic = MAGIC;
    h -> sz = size;
    msize += size + sizeof(struct header);
    if(is_realloc!=1)
	    log_size("alloc");
    return (void *)(h + 1);
}

static void
my_free_default(void *opaque, void *ptr)
{
   if (ptr != NULL) {
        struct header * h = ((struct header *)ptr) - 1;
        if (h -> magic != MAGIC) { /* Not allocated by us */
        } else {
            msize -= h -> sz + sizeof(struct header);
            free(h);
        }
   }
   if(is_realloc!=1)
	   log_size("free");
}

static void *
my_realloc_default(void *opaque, void *old, unsigned int size)
{
	void * newp;
    if (old==NULL) { //practically, it's a malloc
    	newp = my_malloc_default(opaque, size);
    } else {
    	struct header * h = ((struct header *)old) - 1;
		if (h -> magic != MAGIC) { // Not allocated by my_malloc_default
			printf("§§§ warn: not allocated by my_malloc_default, new size: %i\n",size);
			newp = realloc(old,size);
		} else { // malloc + free
			is_realloc = 1;
			size_t oldsize = h -> sz;
			//printf("realloc %i -> %i\n",oldsize,size);
			newp = my_malloc_default(opaque, size);
			if (NULL != newp) {
				memcpy(newp, old, oldsize<size?oldsize:size);
				my_free_default(opaque, old);
			}
			log_size("realloc");
			is_realloc = 0;
		}
	}

	return(newp);
}

fz_alloc_context my_alloc_default =
{
	NULL,
	my_malloc_default,
	my_realloc_default,
	my_free_default
};



static int openDocument(lua_State *L) {
	char *filename = strdup(luaL_checkstring(L, 1));
	int cache_size = luaL_optint(L, 2, 64 << 20); // 64 MB limit default
	char buf[15];
	printf("## cache_size: %s\n",readable_fs(cache_size,buf));

	PdfDocument *doc = (PdfDocument*) lua_newuserdata(L, sizeof(PdfDocument));

	luaL_getmetatable(L, "pdfdocument");
	lua_setmetatable(L, -2);

	doc->context = fz_new_context(&my_alloc_default, NULL, cache_size);

	fz_try(doc->context) {
		doc->xref = fz_open_document(doc->context, filename);
	}
	fz_catch(doc->context) {
		free(filename);
		return luaL_error(L, "cannot open PDF file");
	}

	free(filename);
	return 1;
}

static int needsPassword(lua_State *L) {
	PdfDocument *doc = (PdfDocument*) luaL_checkudata(L, 1, "pdfdocument");
	lua_pushboolean(L, fz_needs_password(doc->xref));
	return 1;
}

static int authenticatePassword(lua_State *L) {
	PdfDocument *doc = (PdfDocument*) luaL_checkudata(L, 1, "pdfdocument");
	char *password = strdup(luaL_checkstring(L, 2));

	if (!fz_authenticate_password(doc->xref, password)) {
		lua_pushboolean(L, 0);
	} else {
		lua_pushboolean(L, 1);
	}
	free(password);
	return 1;
}

static int closeDocument(lua_State *L) {
	PdfDocument *doc = (PdfDocument*) luaL_checkudata(L, 1, "pdfdocument");
	if(doc->xref != NULL) {
		fz_close_document(doc->xref);
		doc->xref = NULL;
	}
	if(doc->context != NULL) {
		fz_free_context(doc->context);
		doc->context = NULL;
	}
	return 0;
}

static int getNumberOfPages(lua_State *L) {
	PdfDocument *doc = (PdfDocument*) luaL_checkudata(L, 1, "pdfdocument");
	fz_try(doc->context) {
		lua_pushinteger(L, fz_count_pages(doc->xref));
	}
	fz_catch(doc->context) {
		return luaL_error(L, "cannot access page tree");
	}
	return 1;
}

/*
 * helper function for getTableOfContent()
 */
static int walkTableOfContent(lua_State *L, fz_outline* ol, int *count, int depth) {
	depth++;
	while(ol) {
		lua_pushnumber(L, *count);

		/* set subtable */
		lua_newtable(L);
		lua_pushstring(L, "page");
		lua_pushnumber(L, ol->dest.ld.gotor.page + 1);
		lua_settable(L, -3);

		lua_pushstring(L, "depth");
		lua_pushnumber(L, depth);
		lua_settable(L, -3);

		lua_pushstring(L, "title");
		lua_pushstring(L, ol->title);
		lua_settable(L, -3);


		lua_settable(L, -3);
		(*count)++;
		if (ol->down) {
			walkTableOfContent(L, ol->down, count, depth);
		}
		ol = ol->next;
	}
	return 0;
}

/*
 * Return a table like this:
 * {
 *		{page=12, depth=1, title="chapter1"},
 *		{page=54, depth=1, title="chapter2"},
 * }
 */
static int getTableOfContent(lua_State *L) {
	fz_outline *ol;
	int count = 1;

	PdfDocument *doc = (PdfDocument*) luaL_checkudata(L, 1, "pdfdocument");
	ol = fz_load_outline(doc->xref);

	lua_newtable(L);
	walkTableOfContent(L, ol, &count, 0);
	return 1;
}

static int openPage(lua_State *L) {
	fz_device *dev;

	PdfDocument *doc = (PdfDocument*) luaL_checkudata(L, 1, "pdfdocument");

	int pageno = luaL_checkint(L, 2);

	fz_try(doc->context) {
		if(pageno < 1 || pageno > fz_count_pages(doc->xref)) {
			return luaL_error(L, "cannot open page #%d, out of range (1-%d)",
					pageno, fz_count_pages(doc->xref));
		}

		PdfPage *page = (PdfPage*) lua_newuserdata(L, sizeof(PdfPage));

		luaL_getmetatable(L, "pdfpage");
		lua_setmetatable(L, -2);

		page->page = fz_load_page(doc->xref, pageno - 1);

		page->doc = doc;
	}
	fz_catch(doc->context) {
		return luaL_error(L, "cannot open page #%d", pageno);
	}
	showMsize();
	return 1;
}

static int getPageSize(lua_State *L) {
	fz_matrix ctm;
	fz_rect bounds;
	fz_rect bbox;
	PdfPage *page = (PdfPage*) luaL_checkudata(L, 1, "pdfpage");
	DrawContext *dc = (DrawContext*) luaL_checkudata(L, 2, "drawcontext");

	bounds = fz_bound_page(page->doc->xref, page->page);
	ctm = fz_scale(dc->zoom, dc->zoom) ;
	ctm = fz_concat(ctm, fz_rotate(dc->rotate));
	bbox = fz_transform_rect(ctm, bounds);

    lua_pushnumber(L, bbox.x1-bbox.x0);
	lua_pushnumber(L, bbox.y1-bbox.y0);

	return 2;
}

static int getUsedBBox(lua_State *L) {
	fz_bbox result;
	fz_matrix ctm;
	fz_device *dev;
	PdfPage *page = (PdfPage*) luaL_checkudata(L, 1, "pdfpage");

	/* returned BBox is in centi-point (n * 0.01 pt) */
	ctm = fz_scale(100, 100);

	fz_try(page->doc->context) {
		dev = fz_new_bbox_device(page->doc->context, &result);
		fz_run_page(page->doc->xref, page->page, dev, ctm, NULL);
	}
	fz_always(page->doc->context) {
		fz_free_device(dev);
	}
	fz_catch(page->doc->context) {
		return luaL_error(L, "cannot calculate bbox for page");
	}

       	lua_pushnumber(L, ((double)result.x0)/100);
	lua_pushnumber(L, ((double)result.y0)/100);
       	lua_pushnumber(L, ((double)result.x1)/100);
	lua_pushnumber(L, ((double)result.y1)/100);

	return 4;
}

static int closePage(lua_State *L) {
	PdfPage *page = (PdfPage*) luaL_checkudata(L, 1, "pdfpage");
	if(page->page != NULL) {
		fz_free_page(page->doc->xref, page->page);
		page->page = NULL;
	}
	return 0;
}

static int drawPage(lua_State *L) {
	fz_pixmap *pix;
	fz_device *dev;
	fz_matrix ctm;
	fz_bbox bbox;
	fz_bbox rect;

	PdfPage *page = (PdfPage*) luaL_checkudata(L, 1, "pdfpage");
	DrawContext *dc = (DrawContext*) luaL_checkudata(L, 2, "drawcontext");
	BlitBuffer *bb = (BlitBuffer*) luaL_checkudata(L, 3, "blitbuffer");
	rect.x0 = luaL_checkint(L, 4);
	rect.y0 = luaL_checkint(L, 5);
	rect.x1 = rect.x0 + bb->w;
	rect.y1 = rect.y0 + bb->h;
	pix = fz_new_pixmap_with_rect(page->doc->context, fz_device_gray, rect);
	fz_clear_pixmap_with_value(page->doc->context, pix, 0xff);

	ctm = fz_scale(dc->zoom, dc->zoom);
	ctm = fz_concat(ctm, fz_rotate(dc->rotate));
	ctm = fz_concat(ctm, fz_translate(dc->offset_x, dc->offset_y));
	dev = fz_new_draw_device(page->doc->context, pix);
#ifdef MUPDF_TRACE
	fz_device *tdev;
	fz_try(page->doc->context) {
		tdev = fz_new_trace_device(page->doc->context);
		fz_run_page(page->doc->xref, page->page, tdev, ctm, NULL);
	}
	fz_always(page->doc->context) {
		fz_free_device(tdev);
	}
#endif
	fz_run_page(page->doc->xref, page->page, dev, ctm, NULL);
	fz_free_device(dev);

	if(dc->gamma >= 0.0) {
		fz_gamma_pixmap(page->doc->context, pix, dc->gamma);
	}

	uint8_t *bbptr = (uint8_t*)bb->data;
	uint16_t *pmptr = (uint16_t*)pix->samples;
	int x, y;

	for(y = 0; y < bb->h; y++) {
		for(x = 0; x < (bb->w / 2); x++) {
			bbptr[x] = (((pmptr[x*2 + 1] & 0xF0) >> 4) | (pmptr[x*2] & 0xF0)) ^ 0xFF;
		}
		if(bb->w & 1) {
			bbptr[x] = (pmptr[x*2] & 0xF0) ^ 0xF0;
		}
		bbptr += bb->pitch;
		pmptr += bb->w;
	}

	fz_drop_pixmap(page->doc->context, pix);

	return 0;
}

static int getCacheSize(lua_State *L) {
	printf("## mupdf getCacheSize = %d\n", msize);
	lua_pushnumber(L, msize);
	return 1;
}

static int cleanCache(lua_State *L) {
	printf("## mupdf cleanCache NOP\n");
	return 0;
}

static const struct luaL_Reg pdf_func[] = {
	{"openDocument", openDocument},
	{NULL, NULL}
};

static const struct luaL_Reg pdfdocument_meth[] = {
	{"needsPassword", needsPassword},
	{"authenticatePassword", authenticatePassword},
	{"openPage", openPage},
	{"getPages", getNumberOfPages},
	{"getTOC", getTableOfContent},
	{"close", closeDocument},
	{"getCacheSize", getCacheSize},
	{"cleanCache", cleanCache},
	{"__gc", closeDocument},
	{NULL, NULL}
};

static const struct luaL_Reg pdfpage_meth[] = {
	{"getSize", getPageSize},
	{"getUsedBBox", getUsedBBox},
	{"close", closePage},
	{"__gc", closePage},
	{"draw", drawPage},
	{NULL, NULL}
};

int luaopen_pdf(lua_State *L) {
	luaL_newmetatable(L, "pdfdocument");
	lua_pushstring(L, "__index");
	lua_pushvalue(L, -2);
	lua_settable(L, -3);
	luaL_register(L, NULL, pdfdocument_meth);
	lua_pop(L, 1);
	luaL_newmetatable(L, "pdfpage");
	lua_pushstring(L, "__index");
	lua_pushvalue(L, -2);
	lua_settable(L, -3);
	luaL_register(L, NULL, pdfpage_meth);
	lua_pop(L, 1);
	luaL_register(L, "pdf", pdf_func);
	return 1;
}