/*****************************************************************************
 * pce                                                                       *
 *****************************************************************************/

/*****************************************************************************
 * File name:   src/arch/ibmpc/cassette.c                                    *
 * Created:     2008-11-25 by Hampa Hug <hampa@hampa.ch>                     *
 * Copyright:   (C) 2008-2019 Hampa Hug <hampa@hampa.ch>                     *
 *****************************************************************************/

/*****************************************************************************
 * This program is free software. You can redistribute it and / or modify it *
 * under the terms of the GNU General Public License version 2 as  published *
 * by the Free Software Foundation.                                          *
 *                                                                           *
 * 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.                                          *
 *****************************************************************************/

#include <stdarg.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <wchar.h>

#define HAVE_STDARG_H
#include <86box/86box.h>
#include <86box/device.h>
#include "cpu.h"
#include <86box/machine.h>
#include <86box/plat.h>
#include <86box/ui.h>
#include <86box/timer.h>
#include <86box/pit.h>
#include <86box/cassette.h>

// #include <lib/console.h>

#define CAS_CLK 1193182

pc_cassette_t *cassette;

char          cassette_fname[512];
char          cassette_mode[512];
unsigned long cassette_pos;
unsigned long cassette_srate;
int           cassette_enable;
int           cassette_append;
int           cassette_pcm;
int           cassette_ui_writeprot;

static int cassette_cycles = -1;

static void pc_cas_reset(pc_cassette_t *cas);

#ifdef ENABLE_CASSETTE_LOG
int cassette_do_log = ENABLE_CASSETTE_LOG;

static void
cassette_log(const char *fmt, ...)
{
    va_list ap;

    if (cassette_do_log) {
        va_start(ap, fmt);
        pclog_ex(fmt, ap);
        va_end(ap);
    }
}
#else
#    define cassette_log(fmt, ...)
#endif

void
pc_cas_init(pc_cassette_t *cas)
{
    cas->save = 0;
    cas->pcm  = 0;

    cas->motor = 0;
    ui_sb_update_icon(SB_CASSETTE, 0);

    cas->position = 0;

    cas->position_save = 0;
    cas->position_load = 0;

    cas->data_out = 0;
    cas->data_inp = 0;

    cas->pcm_out_vol = 64;
    cas->pcm_out_val = 0;

    cas->cas_out_cnt = 0;
    cas->cas_out_buf = 0;

    cas->cas_inp_cnt = 0;
    cas->cas_inp_buf = 0;
    cas->cas_inp_bit = 0;

    cas->clk = 0;

    cas->clk_pcm = 0;

    cas->clk_out = 0;
    cas->clk_inp = 0;

    cas->srate = 44100;

    cas->close = 0;
    cas->fname = NULL;
    cas->fp    = NULL;

    pc_cas_reset(cas);
}

void
pc_cas_free(pc_cassette_t *cas)
{
    free(cas->fname);

    if (cas->close) {
        fclose(cas->fp);
    }
}

pc_cassette_t *
pc_cas_new(void)
{
    pc_cassette_t *cas;

    cas = malloc(sizeof(pc_cassette_t));

    if (cas == NULL) {
        return (NULL);
    }

    pc_cas_init(cas);

    return cas;
}

void
pc_cas_del(pc_cassette_t *cas)
{
    if (cas != NULL) {
        pc_cas_free(cas);
        free(cas);
    }
}

int
pc_cas_set_fname(pc_cassette_t *cas, const char *fname)
{
    unsigned    n;
    const char *ext;

    if (cas->close)
        fclose(cas->fp);

    cas->close = 0;
    cas->fp    = NULL;

    free(cas->fname);
    cas->fname = NULL;

    cas->position = 0;

    cas->position_save = 0;
    cas->position_load = 0;

    if (fname == NULL) {
        ui_sb_update_icon_state(SB_CASSETTE, 1);
        return 0;
    }

    cas->fp = plat_fopen(fname, "r+b");

    if (cas->fp == NULL)
        cas->fp = plat_fopen(fname, "w+b");

    if (cas->fp == NULL) {
        ui_sb_update_icon_state(SB_CASSETTE, 1);
        return 1;
    }

    cas->close = 1;

    pc_cas_append(cas);

    cas->position_save = cas->position;

    if (cas->save == 0)
        pc_cas_set_position(cas, 0);

    n = strlen(fname);

    cas->fname = malloc((n + 1) * sizeof(char));

    if (cas->fname != NULL)
        memcpy(cas->fname, fname, (n + 1) * sizeof(char));

    if (n > 4) {
        ext = fname + (n - 4);

        /* Has to be 44.1 kHz, mono, 8-bit. */
        if (stricmp(ext, ".pcm") == 0)
            pc_cas_set_pcm(cas, 1);
        else if (stricmp(ext, ".raw") == 0)
            pc_cas_set_pcm(cas, 1);
        else if (stricmp(ext, ".wav") == 0)
            pc_cas_set_pcm(cas, 1);
        else if (stricmp(ext, ".cas") == 0)
            pc_cas_set_pcm(cas, 0);
    }

    return 0;
}

static void
pc_cas_reset(pc_cassette_t *cas)
{
    cas->clk_pcm = 0;

    cas->clk_out = cas->clk;
    cas->clk_inp = 0;

    cas->pcm_out_val = 0;

    cas->cas_out_cnt = 0;
    cas->cas_out_buf = 0;

    cas->cas_inp_cnt = 0;
    cas->cas_inp_buf = 0;
    cas->cas_inp_bit = 0;

    for (uint8_t i = 0; i < 3; i++) {
        cas->pcm_inp_fir[i] = 0;
    }
}

int
pc_cas_get_mode(const pc_cassette_t *cas)
{
    return (cas->save);
}

void
pc_cas_set_mode(pc_cassette_t *cas, int save)
{
    save = (save != 0);

    if (cas->save == save) {
        return;
    }

    if (cas->save) {
        cas->position_save = cas->position;
        cas->position      = cas->position_load;
    } else {
        cas->position_load = cas->position;
        cas->position      = cas->position_save;
    }

    cas->save = save;

    memset(cassette_mode, 0x00, sizeof(cassette_mode));
    if (save)
        memcpy(cassette_mode, "save", strlen("save") + 1);
    else
        memcpy(cassette_mode, "load", strlen("load") + 1);

    if (cas->fp != NULL) {
        fflush(cas->fp);

        pc_cas_set_position(cas, cas->position);
    }

    pc_cas_reset(cas);
}

int
pc_cas_get_pcm(const pc_cassette_t *cas)
{
    return (cas->pcm);
}

void
pc_cas_set_pcm(pc_cassette_t *cas, int pcm)
{
    cas->pcm = (pcm != 0);

    cassette_pcm = (pcm != 0);

    pc_cas_reset(cas);
}

unsigned long
pc_cas_get_srate(const pc_cassette_t *cas)
{
    return (cas->srate);
}

void
pc_cas_set_srate(pc_cassette_t *cas, unsigned long srate)
{
    cas->srate = srate;

    pc_cas_reset(cas);
}

void
pc_cas_rewind(pc_cassette_t *cas)
{
    if (cas->fp != NULL) {
        rewind(cas->fp);
        cas->position = 0;
    }

    pc_cas_reset(cas);
}

void
pc_cas_append(pc_cassette_t *cas)
{
    if (cas->fp != NULL) {
        fseek(cas->fp, 0, SEEK_END);
        cas->position = ftell(cas->fp);
    }

    pc_cas_reset(cas);
}

unsigned long
pc_cas_get_position(const pc_cassette_t *cas)
{
    return (cas->position);
}

int
pc_cas_set_position(pc_cassette_t *cas, unsigned long pos)
{
    if (cas->fp == NULL) {
        return 1;
    }

    if (fseek(cas->fp, pos, SEEK_SET) != 0) {
        return 1;
    }

    cas->position = pos;

    pc_cas_reset(cas);

    return 0;
}

static void
pc_cas_read_bit(pc_cassette_t *cas)
{
    int val;

    if (cas->cas_inp_cnt == 0) {
        if (cas->fp == NULL) {
            return;
        }

        if (feof(cas->fp)) {
            return;
        }

        val = fgetc(cas->fp);

        if (val == EOF) {
            cassette_log("cassette EOF at %lu\n", cas->position);
            return;
        }

        cas->position += 1;

        cas->cas_inp_cnt = 8;
        cas->cas_inp_buf = val;
    }

    cas->cas_inp_bit = ((cas->cas_inp_buf & 0x80) != 0);

    cas->cas_inp_buf = (cas->cas_inp_buf << 1) & 0xff;
    cas->cas_inp_cnt -= 1;
}

static int
pc_cas_read_smp(pc_cassette_t *cas)
{
    int  smp;
    int *fir;

    if (feof(cas->fp)) {
        return 0;
    }

    smp = fgetc(cas->fp);

    if (smp == EOF) {
        cassette_log("cassette EOF at %lu\n", cas->position);
        return 0;
    }

    cas->position += 1;

    fir = cas->pcm_inp_fir;

    fir[0] = fir[1];
    fir[1] = fir[2];
    fir[2] = (smp & 0x80) ? (smp - 256) : smp;

    smp = (fir[0] + 2 * fir[1] + fir[2]) / 4;

    return smp;
}

static void
pc_cas_write_bit(pc_cassette_t *cas, unsigned char val)
{
    if (val && !cassette_ui_writeprot) {
        cas->cas_out_buf |= (0x80 >> cas->cas_out_cnt);
    }

    cas->cas_out_cnt += 1;

    if (cas->cas_out_cnt >= 8) {
        if (cas->fp != NULL) {
            if (!cassette_ui_writeprot)
                fputc(cas->cas_out_buf, cas->fp);
            cas->position += 1;
        }

        cas->cas_out_buf = 0;
        cas->cas_out_cnt = 0;
    }
}

static void
pc_cas_write_smp(pc_cassette_t *cas, int val)
{
    unsigned char smp;

    if (val < 0) {
        smp = (val < -127) ? 0x80 : (val + 256);
    } else {
        smp = (val > 127) ? 0x7f : val;
    }

    if (!cassette_ui_writeprot)
        fputc(smp, cas->fp);

    cas->position += 1;
}

void
pc_cas_set_motor(pc_cassette_t *cas, unsigned char val)
{
    val = (val != 0);

    if (val == cas->motor) {
        return;
    }

    if ((val == 0) && cas->save && cas->pcm) {
        for (unsigned long i = 0; i < (cas->srate / 16); i++) {
            pc_cas_write_smp(cas, 0);
        }
    }

    cassette_log("cassette %S at %lu motor %s\n", (cas->fname != NULL) ? cas->fname : "<none>", cas->position, val ? "on" : "off");

    cas->motor = val;

    if (cas->fp != NULL) {
        fflush(cas->fp);

        pc_cas_set_position(cas, cas->position);
    }

    pc_cas_reset(cas);

    if (cas->motor)
        timer_set_delay_u64(&cas->timer, 8ULL * PITCONST);
    else
        timer_disable(&cas->timer);

    ui_sb_update_icon(SB_CASSETTE, !!val);
}

unsigned char
pc_cas_get_inp(const pc_cassette_t *cas)
{
    return (cas->data_inp);
}

void
pc_cas_set_out(pc_cassette_t *cas, unsigned char val)
{
    unsigned long clk;

    val = (val != 0);

    if (cas->motor == 0) {
        cas->data_inp = val;
        return;
    }

    if (cas->data_out == val) {
        return;
    }

    cas->data_out = val;

    if (cas->pcm) {
        cas->pcm_out_val = val ? -cas->pcm_out_vol : cas->pcm_out_vol;
        return;
    }

    if (cas->save == 0) {
        return;
    }

    if (val == 0) {
        return;
    }

    clk          = cas->clk - cas->clk_out;
    cas->clk_out = cas->clk;

    if (clk < (CAS_CLK / 4000)) {
        ;
    } else if (clk < ((3 * CAS_CLK) / 4000)) {
        pc_cas_write_bit(cas, 0);
    } else if (clk < ((5 * CAS_CLK) / 4000)) {
        pc_cas_write_bit(cas, 1);
    }
}

void
pc_cas_print_state(UNUSED(const pc_cassette_t *cas))
{
    cassette_log("%s %s %lu %s %lu\n", (cas->fname != NULL) ? cas->fname : "<none>", cas->pcm ? "pcm" : "cas", cas->srate, cas->save ? "save" : "load", cas->position);
}

static void
pc_cas_clock_pcm(pc_cassette_t *cas, unsigned long cnt)
{
    uint64_t n;
    int      v = 0;

    n = cas->srate * cnt + cas->clk_pcm;

    cas->clk_pcm = n % CAS_CLK;

    n = n / CAS_CLK;

    if (n == 0) {
        return;
    }

    if (cas->save) {
        for (uint64_t i = 0; i < n; i++) {
            pc_cas_write_smp(cas, cas->pcm_out_val);
        }
    } else {
        for (uint64_t i = 0; i < n; i++) {
            v = pc_cas_read_smp(cas);
        }

        cas->data_inp = (v < 0) ? 0 : 1;
    }
}

void
pc_cas_clock(pc_cassette_t *cas, unsigned long cnt)
{
    cas->clk += cnt;

    if (cas->motor == 0) {
        return;
    }

    if (cas->pcm) {
        pc_cas_clock_pcm(cas, cnt);
        return;
    }

    if (cas->save) {
        return;
    }

    if (cas->clk_inp > cnt) {
        cas->clk_inp -= cnt;
        return;
    }

    cnt -= cas->clk_inp;

    cas->data_inp = !cas->data_inp;

    if (cas->data_inp) {
        pc_cas_read_bit(cas);
    }

    if (cas->cas_inp_bit) {
        cas->clk_inp = CAS_CLK / 2000;
    } else {
        cas->clk_inp = CAS_CLK / 4000;
    }

    if (cas->clk_inp > cnt) {
        cas->clk_inp -= cnt;
    }
}

void
pc_cas_advance(pc_cassette_t *cas)
{
    int ticks;
    cpu_s = (CPU *) &cpu_f->cpus[cpu_effective];

    if (cas->motor == 0)
        return;

    if (cassette_cycles == -1)
        cassette_cycles = cycles;
    if (cycles <= cassette_cycles)
        ticks = (cassette_cycles - cycles);
    else
        ticks = (cassette_cycles + (cpu_s->rspeed / 100) - cycles);
    cassette_cycles = cycles;

    pc_cas_clock(cas, ticks);
}

static void
cassette_close(UNUSED(void *priv))
{
    if (cassette != NULL) {
        free(cassette);
        cassette = NULL;
    }
}

static void
cassette_callback(void *priv)
{
    pc_cassette_t *cas = (pc_cassette_t *) priv;

    pc_cas_clock(cas, 8);

    if (cas->motor)
        ui_sb_update_icon(SB_CASSETTE, 1);

    timer_advance_u64(&cas->timer, 8ULL * PITCONST);
}

static void *
cassette_init(UNUSED(const device_t *info))
{
    cassette = NULL;

    if (cassette_pcm == 1)
        cassette_pcm = -1;

    cassette_log("CASSETTE: file=%s mode=%s pcm=%d srate=%lu pos=%lu append=%d\n",
                 (cassette_fname != NULL) ? cassette_fname : "<none>", cassette_mode, cassette_pcm, cassette_srate, cassette_pos, cassette_append);

    cassette = pc_cas_new();

    if (cassette == NULL) {
        cassette_log("ERROR: *** alloc failed\n");
        return NULL;
    }

    if (strlen(cassette_fname) == 0) {
        if (pc_cas_set_fname(cassette, NULL)) {
            cassette_log("ERROR: *** opening file failed (%s)\n", cassette_fname);
        }
    } else {
        if (pc_cas_set_fname(cassette, cassette_fname)) {
            cassette_log("ERROR: *** opening file failed (%s)\n", cassette_fname);
        }
    }

    if (strcmp(cassette_mode, "load") == 0)
        pc_cas_set_mode(cassette, 0);
    else if (strcmp(cassette_mode, "save") == 0)
        pc_cas_set_mode(cassette, 1);
    else {
        cassette_log("ERROR: *** unknown cassette mode (%s)\n", cassette_mode);
    }

    if (cassette_append)
        pc_cas_append(cassette);
    else
        pc_cas_set_position(cassette, cassette_pos);

    if (cassette_pcm >= 0)
        pc_cas_set_pcm(cassette, cassette_pcm);

    pc_cas_set_srate(cassette, cassette_srate);

    timer_add(&cassette->timer, cassette_callback, cassette, 0);

    return cassette;
}

const device_t cassette_device = {
    .name          = "IBM PC/PCjr Cassette Device",
    .internal_name = "cassette",
    .flags         = 0,
    .local         = 0,
    .init          = cassette_init,
    .close         = cassette_close,
    .reset         = NULL,
    { .available = NULL },
    .speed_changed = NULL,
    .force_redraw  = NULL,
    .config        = NULL
};