/** \file   vsidstate.c
 * \brief   VSID state module
 *
 * This module is a central place to keep track of the state of the VSID UI and
 * handle communication between the VICE thread and the UI thread.
 *
 * \author  Bas Wassink <b.wassink@ziggo.nl>
 */

#include "vice.h"

#include <stddef.h>
#include <stdint.h>
#include <stdbool.h>
#include <string.h>
#include <pthread.h>
#include "lib.h"
#include "log.h"

#include "vsidstate.h"


/** \brief  UI state object for threading, do NOT use directly
 *
 * Do not use directly, but use lock_vsid_state()/unlock_vsid_state() to access.
 */
vsid_state_t vsid_state_hands_off;


/** \brief  Mutex to handle UI update requests from the VICE thread.
 */
static pthread_mutex_t vsid_lock = PTHREAD_MUTEX_INITIALIZER;



/** \brief  Get the lock on the VSID state
 *
 * \return  VSID state reference
 */
vsid_state_t *vsid_state_lock(void)
{
    pthread_mutex_lock(&vsid_lock);
    return &vsid_state_hands_off;
}


/** \brief  Unlock the VSID state
 */
void vsid_state_unlock(void)
{
    pthread_mutex_unlock(&vsid_lock);
}


/** \brief  Initialize UI state object
 */
void vsid_state_init(void)
{
    /* during setup we can use the object directly */
    vsid_state_t *state = &vsid_state_hands_off;

    /* Let's be explicit and not rely on automatic initialization to 0/NULL,
     * when the meaning of 0/NULL for a member changes we're in for some weird
     * bugs.
     */
    state->psid_filename = NULL;
    state->name = NULL;
    state->author = NULL;
    state->copyright = NULL;
    state->irq = NULL;
    state->tune_count = 0;
    state->tune_count_pending = false;
    state->tune_current = -1;
    state->tune_current_pending = false;
    state->tune_previous = -1;
    state->tune_default = 0;
    state->tune_default_pending = false;
    memset(state->tunes_played, 0, sizeof(state->tunes_played));
    state->model = 0;
    state->model_pending = false;
    state->sync = 0;
    state->sync_pending = false;
    state->load_addr = 0;
    state->load_addr_pending = false;
    state->init_addr = 0;
    state->init_addr_pending = false;
    state->play_addr = 0;
    state->play_addr_pending = false;
    state->data_size = 0;
    state->data_size_pending = false;

    state->current_time = ~0;   /*  force rendering of play time once after */
    state->new_time = 0;        /*+ UI realization */
    state->driver_addr = 0;
    state->driver_addr_pending = false;
}


/** \brief  Clean up any resources used by the VSID state object
 */
void vsid_state_shutdown(void)
{
    vsid_state_t *state = vsid_state_lock();

    if (state->psid_filename != NULL) {
        lib_free(state->psid_filename);
        state->psid_filename = NULL;
    }
    if (state->name != NULL) {
        lib_free(state->name);
        state->name = NULL;
    }
    if (state->author != NULL) {
        lib_free(state->author);
        state->author = NULL;
    }
    if (state->copyright != NULL) {
        lib_free(state->copyright);
        state->copyright = NULL;
    }
    if (state->irq != NULL) {
        lib_free(state->irq);
        state->irq = NULL;
    }

    vsid_state_unlock();
}



/** \brief  Set subtune play flag without using the lock
 *
 * Here be dragons: only call this when having manually obtained the lock!
 *
 * \param[in]   tune    subtune number
 */
void vsid_state_set_tune_played_unlocked(int tune)
{
    vsid_state_t *state = &vsid_state_hands_off;

    if (tune < 1 || tune > 255) {
        return;
    }
    state->tunes_played[(tune - 1) >> 3] |= (1 << ((tune - 1) & 7));
}


/** \brief  Set subtune played flag
 *
 * \param[in]   tune    tune number (1-255)
 */
void vsid_state_set_tune_played(int tune)
{
    if (tune < 1 || tune > 255) {
        return;
    }
    vsid_state_lock();
    vsid_state_set_tune_played_unlocked(tune);
    vsid_state_unlock();
}


/** \brief  Mark current tune as played without obtaining the lock
 *
 * Make sure to have obtained the lock manually before using!
 */
void vsid_state_set_current_tune_played_unlocked(void)
{
    vsid_state_t *state = &vsid_state_hands_off;
    int tune;

    tune = state->tune_current;
    if (tune > 0 && tune < 256) {
        state->tunes_played[(tune - 1) >> 3] |= (1 << ((tune - 1) & 7));
    }
}


/** \brief  Mark current tune as played
 */
void vsid_state_set_current_tune_played(void)
{
    vsid_state_lock();
    vsid_state_set_current_tune_played_unlocked();
    vsid_state_unlock();
}


/** \brief  Determine if a subtune has been played
 *
 * \param[in]   tune    subtune number (1-255)
 *
 * \return  `true` if subtune has been played
 * \note    returns `false` when tune is out of range
 */
bool vsid_state_get_tune_played(int tune)
{
    vsid_state_t *state;
    bool played;

    if (tune < 1 || tune > 255) {
        return false;
    }
    state = vsid_state_lock();
    played = (bool)(state->tunes_played[(tune - 1) >> 3] & (1 << ((tune - 1) & 7)));
    vsid_state_unlock();
    return played;
}


/** \brief  Clear subtune played flag
 *
 * \param[in]   tune    tune number (1-255)
 */
void vsid_state_unset_tune_played(int tune)
{
    vsid_state_t *state;

    if (tune < 1 || tune > 255) {
        return;
    }
    state = vsid_state_lock();
    state->tunes_played[(tune - 1) >> 3] &= ~(1 << ((tune - 1) & 7));
    vsid_state_unlock();
}


/** \brief  Clear all subtunes' played flags
 */
void vsid_state_clear_tunes_played(void)
{
    vsid_state_t *state = vsid_state_lock();

    memset(state->tunes_played, 0, sizeof(state->tunes_played));
    vsid_state_unlock();
}


/** \brief  Determine if all subtunes have been played
 *
 * \return  `true` if all subtunes have been played
 */
bool vsid_state_get_all_tunes_played(void)
{
    vsid_state_t *state = vsid_state_lock();
    int t = 0;
    bool all = true;

    while (t < state->tune_count && t < (int)sizeof(state->tunes_played) * 8) {
        if ((state->tunes_played[t >> 3] & (1 << (t & 7))) == 0) {
            all = false;
            break;
        }
        t++;
    }
    vsid_state_unlock();
    return all;
}


/** \brief  Get bitmap of tunes played
 *
 * \param[out]  bitmap  buffer to store bitmap, must be (at least) 8 bytes
 */
void vsid_state_get_tunes_played_bitmap(uint8_t *bitmap)
{
    vsid_state_t *state = vsid_state_lock();
    memcpy(bitmap, state->tunes_played, sizeof state->tunes_played);
    vsid_state_unlock();
}


/** \brief  Debug helper: print tunes_played bitmap on stdout
 *
 * Careful! Direct access to state which assumes the caller locks and unlocks!
 */
void vsid_state_print_tunes_played_unlocked(void)
{
    vsid_state_t *state = &vsid_state_hands_off;
    uint8_t played[8];
    int count;
    int t;
    int p = 0;
    char buffer[257];

    count = state->tune_count;
    memcpy(played, state->tunes_played, sizeof played);

    for (t = 0; t < count; t++) {
        if (played[t >> 3] & (1 << (t & 7))) {
            buffer[t] = 'X';
            p++;
        } else {
            buffer[t] = '-';
        }
    }
    buffer[t] = '\0';
    log_debug(LOG_DEFAULT, "VSID STATE: Tunes played: %s (%d/%d)", buffer, p, count);
}


/** \brief  Debug helper: print tunes played bitmap on stdout
 */
void vsid_state_print_tunes_played(void)
{
    vsid_state_lock();
    vsid_state_print_tunes_played_unlocked();
    vsid_state_unlock();
}