/*
 * VARCem   Virtual ARchaeological Computer EMulator.
 *          An emulator of (mostly) x86-based PC systems and devices,
 *          using the ISA,EISA,VLB,MCA  and PCI system buses, roughly
 *          spanning the era between 1981 and 1995.
 *
 *          Implementation of a generic text printer.
 *
 *          Simple old text printers were unable to do any formatting
 *          of the text. They were just sheets of paper with a fixed
 *          size (in the U.S., this would be Letter, 8.5"x11") with a
 *          set of fixed margings to allow for proper operation of the
 *          printer mechanics. This would lead to a page being 66 lines
 *          of 80 characters each.
 *
 *
 *
 * Authors: Fred N. van Kempen, <decwiz@yahoo.com>
 *
 *          Copyright 2018-2019 Fred N. van Kempen.
 *
 *          Redistribution and  use  in source  and binary forms, with
 *          or  without modification, are permitted  provided that the
 *          following conditions are met:
 *
 *          1. Redistributions of  source  code must retain the entire
 *             above notice, this list of conditions and the following
 *             disclaimer.
 *
 *          2. Redistributions in binary form must reproduce the above
 *             copyright  notice,  this list  of  conditions  and  the
 *             following disclaimer in  the documentation and/or other
 *             materials provided with the distribution.
 *
 *          3. Neither the  name of the copyright holder nor the names
 *             of  its  contributors may be used to endorse or promote
 *             products  derived from  this  software without specific
 *             prior written permission.
 *
 * THIS SOFTWARE  IS  PROVIDED BY THE  COPYRIGHT  HOLDERS AND CONTRIBUTORS
 * "AS IS" AND  ANY EXPRESS  OR  IMPLIED  WARRANTIES,  INCLUDING, BUT  NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR PURPOSE  ARE  DISCLAIMED. IN  NO  EVENT  SHALL THE COPYRIGHT
 * HOLDER OR  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL,  EXEMPLARY,  OR  CONSEQUENTIAL  DAMAGES  (INCLUDING,  BUT  NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE  GOODS OR SERVICES;  LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED  AND ON  ANY
 * THEORY OF  LIABILITY, WHETHER IN  CONTRACT, STRICT  LIABILITY, OR  TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING  IN ANY  WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <wchar.h>
#include <86box/86box.h>
#include <86box/device.h>
#include <86box/timer.h>
#include <86box/pit.h>
#include <86box/path.h>
#include <86box/plat.h>
#include <86box/lpt.h>
#include <86box/printer.h>
#include <86box/prt_devs.h>

#define FULL_PAGE 1 /* set if no top/bot margins */

/* Default page values (for now.) */
#define PAGE_WIDTH   8.5 /* standard U.S. Letter */
#define PAGE_HEIGHT  11
#define PAGE_LMARGIN 0.25 /* 0.25" left and right */
#define PAGE_RMARGIN 0.25
#if FULL_PAGE
#    define PAGE_TMARGIN 0
#    define PAGE_BMARGIN 0
#else
#    define PAGE_TMARGIN 0.25
#    define PAGE_BMARGIN 0.25
#endif
#define PAGE_CPI 10.0 /* standard 10 cpi */
#define PAGE_LPI 6.0  /* standard 6 lpi */

typedef struct psurface_t {
    int8_t dirty; /* has the page been printed on? */
    char   pad;

    uint8_t w; /* size //INFO */
    uint8_t h;

    char *chars; /* character data */
} psurface_t;

typedef struct prnt_t {
    const char *name;

    void *lpt;

    /* Output file name. */
    char filename[1024];

    /* Printer timeout. */
    pc_timer_t pulse_timer;
    pc_timer_t timeout_timer;

    /* page data (TODO: make configurable) */
    double page_width; /* all in inches */
    double page_height;
    double left_margin;
    double top_margin;
    double right_margin;
    double bot_margin;

    /* internal page data */
    psurface_t *page;
    uint8_t     max_chars;
    uint8_t     max_lines;
    uint8_t     curr_x; /* print head position (x, chars) */
    uint8_t     curr_y; /* print head position (y, chars) */

    /* font data */
    double cpi; /* defined chars per inch */
    double lpi; /* defined lines per inch */

    /* handshake data */
    uint8_t data;
    int8_t  ack;
    int8_t  select;
    int8_t  busy;
    int8_t  int_pending;
    int8_t  error;
    int8_t  autofeed;
    uint8_t ctrl;
} prnt_t;

/* Dump the current page into a formatted file. */
static void
dump_page(prnt_t *dev)
{
    char     path[1024];
    uint8_t  ch;
    FILE    *fp;

    /* Create the full path for this file. */
    memset(path, 0x00, sizeof(path));
    path_append_filename(path, usr_path, "printer");
    if (!plat_dir_check(path))
        plat_dir_create(path);
    path_slash(path);
    strcat(path, dev->filename);

    /* Create the file. */
    fp = plat_fopen(path, "a");
    if (fp == NULL) {
        // ERRLOG("PRNT: unable to create print page '%s'\n", path);
        return;
    }
    fseek(fp, 0, SEEK_END);

    /* If this is not a new file, add a formfeed first. */
    if (ftell(fp) != 0)
        fputc('\014', fp);

    for (uint16_t y = 0; y < dev->curr_y; y++) {
        for (uint16_t x = 0; x < dev->page->w; x++) {
            ch = dev->page->chars[(y * dev->page->w) + x];
            if (ch == 0x00) {
                /* End of line marker. */
                fputc('\n', fp);
                break;
            } else {
                fputc(ch, fp);
            }
        }
    }

    /* All done, close the file. */
    fclose(fp);
}

static void
new_page(prnt_t *dev)
{
    /* Dump the current page if needed. */
    if (dev->page->dirty)
        dump_page(dev);

    /* Clear page. */
    memset(dev->page->chars, 0x00, dev->page->h * dev->page->w);
    dev->curr_y      = 0;
    dev->page->dirty = 0;
}

static void
pulse_timer(void *priv)
{
    prnt_t *dev = (prnt_t *) priv;

    if (dev->ack) {
        dev->ack = 0;
        lpt_irq(dev->lpt, 1);
    }

    timer_disable(&dev->pulse_timer);
}

static void
timeout_timer(void *priv)
{
    prnt_t *dev = (prnt_t *) priv;

    if (dev->page->dirty)
        new_page(dev);

    timer_disable(&dev->timeout_timer);
}

static void
reset_printer(prnt_t *dev)
{
    /* TODO: these three should be configurable */
    dev->page_width   = PAGE_WIDTH;
    dev->page_height  = PAGE_HEIGHT;
    dev->left_margin  = PAGE_LMARGIN;
    dev->right_margin = PAGE_RMARGIN;
    dev->top_margin   = PAGE_TMARGIN;
    dev->bot_margin   = PAGE_BMARGIN;
    dev->cpi          = PAGE_CPI;
    dev->lpi          = PAGE_LPI;
    dev->ack          = 0;

    /* Default page layout. */
    dev->max_chars = (int) ((dev->page_width - dev->left_margin - dev->right_margin) * dev->cpi);
    dev->max_lines = (int) ((dev->page_height - dev->top_margin - dev->bot_margin) * dev->lpi);

    dev->curr_x = dev->curr_y = 0;

    if (dev->page != NULL)
        dev->page->dirty = 0;

    /* Create a file for this page. */
    plat_tempfile(dev->filename, NULL, ".txt");

    timer_disable(&dev->pulse_timer);
    timer_disable(&dev->timeout_timer);
}

static int
process_char(prnt_t *dev, uint8_t ch)
{
    uint8_t i;

    switch (ch) {
        case 0x07: /* Beeper (BEL) */
            /* TODO: beep? */
            return 1;

        case 0x08: /* Backspace (BS) */
            if (dev->curr_x > 0)
                dev->curr_x--;
            return 1;

        case 0x09: /* Tab horizontally (HT) */
            /* Find tab right to current pos. */
            i                                                    = dev->curr_x;
            dev->page->chars[(dev->curr_y * dev->page->w) + i++] = ' ';
            while ((i < dev->max_chars) && ((i % 8) != 0)) {
                dev->page->chars[(dev->curr_y * dev->page->w) + i] = ' ';
                i++;
            }
            dev->curr_x = i;
            return 1;

        case 0x0b: /* Tab vertically (VT) */
            dev->curr_x = 0;
            return 1;

        case 0x0c: /* Form feed (FF) */
            new_page(dev);
            return 1;

        case 0x0d: /* Carriage Return (CR) */
            dev->curr_x = 0;
            if (!dev->autofeed)
                return 1;
            fallthrough;

        case 0x0a: /* Line feed */
            dev->curr_x = 0;
            if (++dev->curr_y >= dev->max_lines)
                new_page(dev);
            return 1;

        case 0x0e: /* select wide printing (SO) */
            /* Ignore. */
            return 1;

        case 0x0f: /* select condensed printing (SI) */
            /* Ignore. */
            return 1;

        case 0x11: /* select printer (DC1) */
            /* Ignore. */
            return 0;

        case 0x12: /* cancel condensed printing (DC2) */
            /* Ignore. */
            return 1;

        case 0x13: /* deselect printer (DC3) */
            /* Ignore. */
            return 1;

        case 0x14: /* cancel double-width printing (one line) (DC4) */
            /* Ignore. */
            return 1;

        case 0x18: /* cancel line (CAN) */
            /* Ignore. */
            return 1;

        case 0x1b: /* ESC */
            /* Ignore. */
            return 1;

        default:
            break;
    }

    /* Just a printable character. */
    return 0;
}

static void
handle_char(prnt_t *dev)
{
    uint8_t ch = dev->data;

    if (dev->page == NULL)
        return;

    if (process_char(dev, ch) == 1) {
        /* Command was processed. */
        return;
    }

    /* Store character in the page buffer. */
    dev->page->chars[(dev->curr_y * dev->page->w) + dev->curr_x] = ch;
    dev->page->dirty                                             = 1;

    /* Update print head position. */
    if (++dev->curr_x >= dev->max_chars) {
        dev->curr_x = 0;
        if (++dev->curr_y >= dev->max_lines)
            new_page(dev);
    }
}

static void
write_data(uint8_t val, void *priv)
{
    prnt_t *dev = (prnt_t *) priv;

    if (dev == NULL)
        return;

    dev->data = val;
}

static void
write_ctrl(uint8_t val, void *priv)
{
    prnt_t *dev = (prnt_t *) priv;

    if (dev == NULL)
        return;

    /* set autofeed value */
    dev->autofeed = val & 0x02 ? 1 : 0;

    if (val & 0x08) { /* SELECT */
        /* select printer */
        dev->select = 1;
    }

    if ((val & 0x04) && !(dev->ctrl & 0x04)) {
        /* reset printer */
        dev->select = 0;

        reset_printer(dev);
    }

    if (!(val & 0x01) && (dev->ctrl & 0x01)) { /* STROBE */
        /* Process incoming character. */
        handle_char(dev);

        /* ACK it, will be read on next READ STATUS. */
        dev->ack = 1;

        timer_set_delay_u64(&dev->pulse_timer, ISACONST);
        timer_set_delay_u64(&dev->timeout_timer, 5000000 * TIMER_USEC);
    }

    dev->ctrl = val;
}

static uint8_t
read_status(void *priv)
{
    const prnt_t *dev = (prnt_t *) priv;
    uint8_t       ret = 0x1f;

    ret |= 0x80;

    if (!dev->ack)
        ret |= 0x40;

    return ret;
}

static void *
prnt_init(void *lpt)
{
    prnt_t *dev;

    /* Initialize a device instance. */
    dev = (prnt_t *) malloc(sizeof(prnt_t));
    memset(dev, 0x00, sizeof(prnt_t));
    dev->ctrl = 0x04;
    dev->lpt  = lpt;

    /* Initialize parameters. */
    reset_printer(dev);

    /* Create a page buffer. */
    dev->page        = (psurface_t *) malloc(sizeof(psurface_t));
    dev->page->w     = dev->max_chars;
    dev->page->h     = dev->max_lines;
    dev->page->chars = (char *) malloc(dev->page->w * dev->page->h);
    memset(dev->page->chars, 0x00, dev->page->w * dev->page->h);

    timer_add(&dev->pulse_timer, pulse_timer, dev, 0);
    timer_add(&dev->timeout_timer, timeout_timer, dev, 0);

    return dev;
}

static void
prnt_close(void *priv)
{
    prnt_t *dev = (prnt_t *) priv;

    if (dev == NULL)
        return;

    if (dev->page) {
        /* print last page if it contains data */
        if (dev->page->dirty)
            dump_page(dev);

        if (dev->page->chars != NULL)
            free(dev->page->chars);
        free(dev->page);
    }

    free(dev);
}

const lpt_device_t lpt_prt_text_device = {
    .name          = "Generic Text Printer",
    .internal_name = "text_prt",
    .init          = prnt_init,
    .close         = prnt_close,
    .write_data    = write_data,
    .write_ctrl    = write_ctrl,
    .read_data     = NULL,
    .read_status   = read_status,
    .read_ctrl     = NULL
};
