/*
 *  cacaview      image viewer for libcaca
 *  Copyright (c) 2003 Sam Hocevar <sam@zoy.org>
 *                All Rights Reserved
 *
 *  $Id$
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the Do What The Fuck You Want To
 *  Public License, Version 2, as published by Sam Hocevar. See
 *  http://sam.zoy.org/wtfpl/COPYING for more details.
 */

#include "config.h"

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#if defined(HAVE_IMLIB2_H)
#   include <Imlib2.h>
#else
#   include <stdio.h>
#endif

#if defined(HAVE_SLEEP)
#   include <windows.h>
#endif

#include "cucul.h"
#include "caca.h"

/* Local macros */
#define MODE_IMAGE 1
#define MODE_FILES 2

#define STATUS_DITHERING 1
#define STATUS_ANTIALIASING 2
#define STATUS_BACKGROUND 3

#define ZOOM_FACTOR 1.08f
#define ZOOM_MAX 50
#define GAMMA_FACTOR 1.04f
#define GAMMA_MAX 100
#define GAMMA(g) (((g) < 0) ? 1.0 / gammatab[-(g)] : gammatab[(g)])
#define PAD_STEP 0.15

/* libcucul/libcaca contexts */
cucul_t *qq; caca_t *kk;

/* Local functions */
static void print_status(void);
static void print_help(int, int);
static void set_zoom(int);
static void set_gamma(int);
static void load_image(char const *);
static void unload_image(void);
static void draw_checkers(int, int, int, int);
#if !defined(HAVE_IMLIB2_H)
static int freadint(FILE *);
static int freadshort(FILE *);
static int freadchar(FILE *);
#endif

/* Local variables */
#if defined(HAVE_IMLIB2_H)
Imlib_Image image = NULL;
#endif
char *pixels = NULL;
struct cucul_bitmap *bitmap = NULL;
unsigned int w, h, depth, bpp, rmask, gmask, bmask, amask;
#if !defined(HAVE_IMLIB2_H)
unsigned int red[256], green[256], blue[256], alpha[256];
#endif

float zoomtab[ZOOM_MAX + 1];
float gammatab[GAMMA_MAX + 1];
float xfactor = 1.0, yfactor = 1.0, dx = 0.5, dy = 0.5;
int zoom = 0, g = 0, fullscreen = 0, mode, ww, wh;

int main(int argc, char **argv)
{
    int quit = 0, update = 1, help = 0, status = 0;
    int reload = 0;

    char **list = NULL;
    int current = 0, items = 0, opts = 1;
    int i;

    /* Initialise libcucul */
    qq = cucul_create(0, 0);
    if(!qq)
    {
        fprintf(stderr, "%s: unable to initialise libcucul\n", argv[0]);
        return 1;
    }

    kk = caca_attach(qq);
    if(!kk)
    {
        fprintf(stderr, "%s: unable to initialise libcaca\n", argv[0]);
        return 1;
    }

    /* Set the window title */
    caca_set_window_title(kk, "cacaview");

    ww = cucul_get_width(qq);
    wh = cucul_get_height(qq);

    /* Fill the zoom table */
    zoomtab[0] = 1.0;
    for(i = 0; i < ZOOM_MAX; i++)
        zoomtab[i + 1] = zoomtab[i] * ZOOM_FACTOR;

    /* Fill the gamma table */
    gammatab[0] = 1.0;
    for(i = 0; i < GAMMA_MAX; i++)
        gammatab[i + 1] = gammatab[i] * GAMMA_FACTOR;

    /* Load items into playlist */
    for(i = 1; i < argc; i++)
    {
        /* Skip options except after `--' */
        if(opts && argv[i][0] == '-')
        {
            if(argv[i][1] == '-' && argv[i][2] == '\0')
                opts = 0;
            continue;
        }

        /* Add argv[i] to the list */
        if(items)
            list = realloc(list, (items + 1) * sizeof(char *));
        else
            list = malloc(sizeof(char *));
        list[items] = argv[i];
        items++;

        reload = 1;
    }

    /* Go ! */
    while(!quit)
    {
        struct caca_event ev;
        unsigned int const event_mask = CACA_EVENT_KEY_PRESS
                                      | CACA_EVENT_RESIZE
                                      | CACA_EVENT_MOUSE_PRESS;
        unsigned int new_status = 0, new_help = 0;
        int event;

        if(update)
            event = caca_get_event(kk, event_mask, &ev, 0);
        else
            event = caca_get_event(kk, event_mask, &ev, -1);

        while(event)
        {
            if(ev.type & CACA_EVENT_MOUSE_PRESS)
            {
                if(ev.data.mouse.button == 1)
                {
                    if(items) current = (current + 1) % items;
                    reload = 1;
                }
                else if(ev.data.mouse.button == 2)
                {
                    if(items) current = (items + current - 1) % items;
                    reload = 1;
                }
            }
            else if(ev.type & CACA_EVENT_KEY_PRESS) switch(ev.data.key.c)
            {
            case 'n':
            case 'N':
                if(items) current = (current + 1) % items;
                reload = 1;
                break;
            case 'p':
            case 'P':
                if(items) current = (items + current - 1) % items;
                reload = 1;
                break;
            case 'f':
            case 'F':
                fullscreen = ~fullscreen;
                update = 1;
                set_zoom(zoom);
                break;
            case 'b':
                i = 1 + cucul_get_feature(qq, CUCUL_BACKGROUND);
                if(i > CUCUL_BACKGROUND_MAX) i = CUCUL_BACKGROUND_MIN;
                cucul_set_feature(qq, i);
                new_status = STATUS_BACKGROUND;
                update = 1;
                break;
            case 'B':
                i = -1 + cucul_get_feature(qq, CUCUL_BACKGROUND);
                if(i < CUCUL_BACKGROUND_MIN) i = CUCUL_BACKGROUND_MAX;
                cucul_set_feature(qq, i);
                new_status = STATUS_BACKGROUND;
                update = 1;
                break;
            case 'a':
                i = 1 + cucul_get_feature(qq, CUCUL_ANTIALIASING);
                if(i > CUCUL_ANTIALIASING_MAX) i = CUCUL_ANTIALIASING_MIN;
                cucul_set_feature(qq, i);
                new_status = STATUS_ANTIALIASING;
                update = 1;
                break;
            case 'A':
                i = -1 + cucul_get_feature(qq, CUCUL_ANTIALIASING);
                if(i < CUCUL_ANTIALIASING_MIN) i = CUCUL_ANTIALIASING_MAX;
                cucul_set_feature(qq, i);
                new_status = STATUS_ANTIALIASING;
                update = 1;
                break;
            case 'd':
                i = 1 + cucul_get_feature(qq, CUCUL_DITHERING);
                if(i > CUCUL_DITHERING_MAX) i = CUCUL_DITHERING_MIN;
                cucul_set_feature(qq, i);
                new_status = STATUS_DITHERING;
                update = 1;
                break;
            case 'D':
                i = -1 + cucul_get_feature(qq, CUCUL_DITHERING);
                if(i < CUCUL_DITHERING_MIN) i = CUCUL_DITHERING_MAX;
                cucul_set_feature(qq, i);
                new_status = STATUS_DITHERING;
                update = 1;
                break;
            case '+':
                update = 1;
                set_zoom(zoom + 1);
                break;
            case '-':
                update = 1;
                set_zoom(zoom - 1);
                break;
            case 'G':
                update = 1;
                set_gamma(g + 1);
                break;
            case 'g':
                update = 1;
                set_gamma(g - 1);
                break;
            case 'x':
            case 'X':
                update = 1;
                set_zoom(0);
                set_gamma(0);
                break;
            case 'k':
            case 'K':
            case CACA_KEY_UP:
                if(yfactor > 1.0) dy -= PAD_STEP / yfactor;
                if(dy < 0.0) dy = 0.0;
                update = 1;
                break;
            case 'j':
            case 'J':
            case CACA_KEY_DOWN:
                if(yfactor > 1.0) dy += PAD_STEP / yfactor;
                if(dy > 1.0) dy = 1.0;
                update = 1;
                break;
            case 'h':
            case 'H':
            case CACA_KEY_LEFT:
                if(xfactor > 1.0) dx -= PAD_STEP / xfactor;
                if(dx < 0.0) dx = 0.0;
                update = 1;
                break;
            case 'l':
            case 'L':
            case CACA_KEY_RIGHT:
                if(xfactor > 1.0) dx += PAD_STEP / xfactor;
                if(dx > 1.0) dx = 1.0;
                update = 1;
                break;
            case '?':
                new_help = !help;
                update = 1;
                break;
            case 'q':
            case 'Q':
                quit = 1;
                break;
            }
            else if(ev.type == CACA_EVENT_RESIZE)
            {
                caca_display(kk);
                ww = ev.data.resize.w;
                wh = ev.data.resize.h;
                update = 1;
                set_zoom(zoom);
            }

            if(status || new_status)
                status = new_status;

            if(help || new_help)
                help = new_help;

            event = caca_get_event(kk, CACA_EVENT_KEY_PRESS, &ev, 0);
        }

        if(items && reload)
        {
            char *buffer;
            int len = strlen(" Loading `%s'... ") + strlen(list[current]);

            if(len < ww + 1)
                len = ww + 1;

            buffer = malloc(len);

            sprintf(buffer, " Loading `%s'... ", list[current]);
            buffer[ww] = '\0';
            cucul_set_color(qq, CUCUL_COLOR_WHITE, CUCUL_COLOR_BLUE);
            cucul_putstr(qq, (ww - strlen(buffer)) / 2, wh / 2, buffer);
            caca_display(kk);
            ww = cucul_get_width(qq);
            wh = cucul_get_height(qq);

            unload_image();
            load_image(list[current]);
            reload = 0;

            /* Reset image-specific runtime variables */
            dx = dy = 0.5;
            update = 1;
            set_zoom(0);
            set_gamma(0);

            free(buffer);
        }

        cucul_clear(qq);

        if(!items)
        {
            cucul_set_color(qq, CUCUL_COLOR_WHITE, CUCUL_COLOR_BLUE);
            cucul_printf(qq, ww / 2 - 5, wh / 2, " No image. ");
        }
        else if(!pixels)
        {
#if defined(HAVE_IMLIB2_H)
#   define ERROR_STRING " Error loading `%s'. "
#else
#   define ERROR_STRING " Error loading `%s'. Only BMP is supported. "
#endif
            char *buffer;
            int len = strlen(ERROR_STRING) + strlen(list[current]);

            if(len < ww + 1)
                len = ww + 1;

            buffer = malloc(len);

            sprintf(buffer, ERROR_STRING, list[current]);
            buffer[ww] = '\0';
            cucul_set_color(qq, CUCUL_COLOR_WHITE, CUCUL_COLOR_BLUE);
            cucul_putstr(qq, (ww - strlen(buffer)) / 2, wh / 2, buffer);
            free(buffer);
        }
        else
        {
            float xdelta, ydelta;
            int y, height;

            y = fullscreen ? 0 : 1;
            height = fullscreen ? wh : wh - 3;

            xdelta = (xfactor > 1.0) ? dx : 0.5;
            ydelta = (yfactor > 1.0) ? dy : 0.5;

            draw_checkers(ww * (1.0 - xfactor) / 2,
                          y + height * (1.0 - yfactor) / 2,
                          ww * (1.0 + xfactor) / 2,
                          y + height * (1.0 + yfactor) / 2);

            cucul_draw_bitmap(qq, ww * (1.0 - xfactor) * xdelta,
                              y + height * (1.0 - yfactor) * ydelta,
                              ww * (xdelta + (1.0 - xdelta) * xfactor),
                              y + height * (ydelta + (1.0 - ydelta) * yfactor),
                              bitmap, pixels);
        }

        if(!fullscreen)
        {
            print_status();

            cucul_set_color(qq, CUCUL_COLOR_LIGHTGRAY, CUCUL_COLOR_BLACK);
            switch(status)
            {
                case STATUS_ANTIALIASING:
                    cucul_printf(qq, 0, wh - 1, "Antialiasing: %s",
                  cucul_get_feature_name(cucul_get_feature(qq, CUCUL_ANTIALIASING)));
                    break;
                case STATUS_DITHERING:
                    cucul_printf(qq, 0, wh - 1, "Dithering: %s",
                  cucul_get_feature_name(cucul_get_feature(qq, CUCUL_DITHERING)));
                    break;
                case STATUS_BACKGROUND:
                    cucul_printf(qq, 0, wh - 1, "Background: %s",
                  cucul_get_feature_name(cucul_get_feature(qq, CUCUL_BACKGROUND)));
                    break;
            }
        }

        if(help)
        {
            print_help(ww - 26, 2);
        }

        caca_display(kk);
        update = 0;
    }

    /* Clean up */
    unload_image();
    caca_detach(kk);
    cucul_free(qq);

    return 0;
}

static void print_status(void)
{
    cucul_set_color(qq, CUCUL_COLOR_WHITE, CUCUL_COLOR_BLUE);
    cucul_draw_line(qq, 0, 0, ww - 1, 0, " ");
    cucul_draw_line(qq, 0, wh - 2, ww - 1, wh - 2, "-");
    cucul_putstr(qq, 0, 0, "q:Quit  np:Next/Prev  +-x:Zoom  gG:Gamma  "
                           "hjkl:Move  d:Dither  a:Antialias");
    cucul_putstr(qq, ww - strlen("?:Help"), 0, "?:Help");
    cucul_printf(qq, 3, wh - 2, "cacaview %s", VERSION);
    cucul_printf(qq, ww - 30, wh - 2, "(gamma: %#.3g)", GAMMA(g));
    cucul_printf(qq, ww - 14, wh - 2, "(zoom: %s%i)", zoom > 0 ? "+" : "", zoom);

    cucul_set_color(qq, CUCUL_COLOR_LIGHTGRAY, CUCUL_COLOR_BLACK);
    cucul_draw_line(qq, 0, wh - 1, ww - 1, wh - 1, " ");
}

static void print_help(int x, int y)
{
    static char const *help[] =
    {
        " +: zoom in              ",
        " -: zoom out             ",
        " g: decrease gamma       ",
        " G: increase gamma       ",
        " x: reset zoom and gamma ",
        " ----------------------- ",
        " hjkl: move view         ",
        " arrows: move view       ",
        " ----------------------- ",
        " a: antialiasing method  ",
        " d: dithering method     ",
        " b: background mode      ",
        " ----------------------- ",
        " ?: help                 ",
        " q: quit                 ",
        NULL
    };

    int i;

    cucul_set_color(qq, CUCUL_COLOR_WHITE, CUCUL_COLOR_BLUE);

    for(i = 0; help[i]; i++)
        cucul_putstr(qq, x, y + i, help[i]);
}

static void set_zoom(int new_zoom)
{
    int height;

    zoom = new_zoom;

    if(zoom > ZOOM_MAX) zoom = ZOOM_MAX;
    if(zoom < -ZOOM_MAX) zoom = -ZOOM_MAX;

    ww = cucul_get_width(qq);
    height = fullscreen ? wh : wh - 3;

    xfactor = (zoom < 0) ? 1.0 / zoomtab[-zoom] : zoomtab[zoom];
    yfactor = xfactor * ww / height * h / w
               * cucul_get_height(qq) / cucul_get_width(qq)
               * caca_get_window_width(kk) / caca_get_window_height(kk);

    if(yfactor > xfactor)
    {
        float tmp = xfactor;
        xfactor = tmp * tmp / yfactor;
        yfactor = tmp;
    }
}

static void set_gamma(int new_gamma)
{
    g = new_gamma;

    if(g > GAMMA_MAX) g = GAMMA_MAX;
    if(g < -GAMMA_MAX) g = -GAMMA_MAX;

    cucul_set_bitmap_gamma(bitmap, (g < 0) ? 1.0 / gammatab[-g] : gammatab[g]);
}

static void unload_image(void)
{
#if defined(HAVE_IMLIB2_H)
    if(image)
        imlib_free_image();
    image = NULL;
    pixels = NULL;
#else
    if(pixels)
        free(pixels);
    pixels = NULL;
#endif
    if(bitmap)
        cucul_free_bitmap(bitmap);
    bitmap = NULL;
}

static void load_image(char const *name)
{
#if defined(HAVE_IMLIB2_H)
    /* Load the new image */
    image = imlib_load_image(name);

    if(!image)
        return;

    imlib_context_set_image(image);
    pixels = (char *)imlib_image_get_data_for_reading_only();
    w = imlib_image_get_width();
    h = imlib_image_get_height();
    rmask = 0x00ff0000;
    gmask = 0x0000ff00;
    bmask = 0x000000ff;
    amask = 0xff000000;
    bpp = 32;
    depth = 4;

    /* Create the libcucul bitmap */
    bitmap = cucul_create_bitmap(bpp, w, h, depth * w,
                                 rmask, gmask, bmask, amask);
    if(!bitmap)
    {
        imlib_free_image();
        image = NULL;
    }

#else
    /* Try to load a BMP file */
    FILE *fp;
    unsigned int i, colors, offset, tmp, planes;

    fp = fopen(name, "rb");
    if(!fp)
        return;

    if(freadshort(fp) != 0x4d42)
    {
        fclose(fp);
        return;
    }

    freadint(fp); /* size */
    freadshort(fp); /* reserved 1 */
    freadshort(fp); /* reserved 2 */

    offset = freadint(fp);

    tmp = freadint(fp); /* header size */
    if(tmp == 40)
    {
        w = freadint(fp);
        h = freadint(fp);
        planes = freadshort(fp);
        bpp = freadshort(fp);

        tmp = freadint(fp); /* compression */
        if(tmp != 0)
        {
            fclose(fp);
            return;
        }

        freadint(fp); /* sizeimage */
        freadint(fp); /* xpelspermeter */
        freadint(fp); /* ypelspermeter */
        freadint(fp); /* biclrused */
        freadint(fp); /* biclrimportantn */

        colors = (offset - 54) / 4;
        for(i = 0; i < colors && i < 256; i++)
        {
            blue[i] = freadchar(fp) * 16;
            green[i] = freadchar(fp) * 16;
            red[i] = freadchar(fp) * 16;
            alpha[i] = 0;
            freadchar(fp);
        }
    }
    else if(tmp == 12)
    {
        w = freadint(fp);
        h = freadint(fp);
        planes = freadshort(fp);
        bpp = freadshort(fp);

        colors = (offset - 26) / 3;
        for(i = 0; i < colors && i < 256; i++)
        {
            blue[i] = freadchar(fp);
            green[i] = freadchar(fp);
            red[i] = freadchar(fp);
            alpha[i] = 0;
        }
    }
    else
    {
        fclose(fp);
        return;
    }

    /* Fill the rest of the palette */
    for(i = colors; i < 256; i++)
        blue[i] = green[i] = red[i] = alpha[i] = 0;

    depth = (bpp + 7) / 8;

    /* Sanity check */
    if(!w || w > 0x10000 || !h || h > 0x10000 || planes != 1 /*|| bpp != 24*/)
    {
        fclose(fp);
        return;
    }

    /* Allocate the pixel buffer */
    pixels = malloc(w * h * depth);
    if(!pixels)
    {
        fclose(fp);
        return;
    }

    memset(pixels, 0, w * h * depth);

    /* Read the bitmap data */
    for(i = h; i--; )
    {
        unsigned int j, k, bits = 0;

        switch(bpp)
        {
            case 1:
                for(j = 0; j < w; j++)
                {
                    k = j % 32;
                    if(k == 0)
                        bits = freadint(fp);
                    pixels[w * i * depth + j] =
                        (bits >> ((k & ~0xf) + 0xf - (k & 0xf))) & 0x1;
                }
                break;
            case 4:
                for(j = 0; j < w; j++)
                {
                    k = j % 8;
                    if(k == 0)
                        bits = freadint(fp);
                    pixels[w * i * depth + j] =
                        (bits >> (4 * ((k & ~0x1) + 0x1 - (k & 0x1)))) & 0xf;
                }
                break;
            default:
                /* Works for 8bpp, but also for 16, 24 etc. */
                fread(pixels + w * i * depth, w * depth, 1, fp);
                /* Pad reads to 4 bytes */
                tmp = (w * depth) % 4;
                tmp = (4 - tmp) % 4;
                while(tmp--)
                    freadchar(fp);
                break;
        }
    }

    switch(depth)
    {
    case 3:
        rmask = 0xff0000;
        gmask = 0x00ff00;
        bmask = 0x0000ff;
        amask = 0x000000;
        break;
    case 2: /* XXX: those are the 16 bits values */
        rmask = 0x7c00;
        gmask = 0x03e0;
        bmask = 0x001f;
        amask = 0x0000;
        break;
    case 1:
    default:
        bpp = 8;
        rmask = gmask = bmask = amask = 0;
        break;
    }

    fclose(fp);

    /* Create the libcucul bitmap */
    bitmap = cucul_create_bitmap(bpp, w, h, depth * w,
                                 rmask, gmask, bmask, amask);
    if(!bitmap)
    {
        free(pixels);
        pixels = NULL;
        return;
    }

    if(bpp == 8)
        cucul_set_bitmap_palette(bitmap, red, green, blue, alpha);
#endif
}

static void draw_checkers(int x1, int y1, int x2, int y2)
{
    int xn, yn;

    if(x2 + 1 > (int)cucul_get_width(qq)) x2 = cucul_get_width(qq) - 1;
    if(y2 + 1 > (int)cucul_get_height(qq)) y2 = cucul_get_height(qq) - 1;

    for(yn = y1 > 0 ? y1 : 0; yn <= y2; yn++)
        for(xn = x1 > 0 ? x1 : 0; xn <= x2; xn++)
    {
        if((((xn - x1) / 5) ^ ((yn - y1) / 3)) & 1)
            cucul_set_color(qq, CUCUL_COLOR_LIGHTGRAY, CUCUL_COLOR_DARKGRAY);
        else
            cucul_set_color(qq, CUCUL_COLOR_DARKGRAY, CUCUL_COLOR_LIGHTGRAY);
        cucul_putchar(qq, xn, yn, ' ');
    }
}

#if !defined(HAVE_IMLIB2_H)
static int freadint(FILE *fp)
{
    unsigned char buffer[4];
    fread(buffer, 4, 1, fp);
    return ((int)buffer[3] << 24) | ((int)buffer[2] << 16)
             | ((int)buffer[1] << 8) | ((int)buffer[0]);
}

static int freadshort(FILE *fp)
{
    unsigned char buffer[2];
    fread(buffer, 2, 1, fp);
    return ((int)buffer[1] << 8) | ((int)buffer[0]);
}

static int freadchar(FILE *fp)
{
    unsigned char buffer;
    fread(&buffer, 1, 1, fp);
    return (int)buffer;
}
#endif