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

#include <xas/object.h>
#include <xas/bank.h>
#include <xas/synth.h>
#include <xas/vox.h>
#include <xas/seq.h>

xas_seq *xas_seq_new(xas_spatial_scene *scene, size_t buffer_size) {
    xas_seq *seq;

    if ((seq = malloc(sizeof(*seq))) == NULL) {
        goto error_malloc_seq;
    }

    seq->scene       = scene;
    seq->first       = NULL;
    seq->last        = NULL;
    seq->buffer_size = buffer_size;

    return seq;

error_malloc_seq:
    return NULL;
}

void xas_seq_destroy(xas_seq *seq) {
    xas_seq_event *event = seq->first;

    while (event) {
        xas_seq_event *next = event->next;

        free(event);

        event = next;
    }

    free(seq);
}

static void add_event(xas_seq *seq, xas_seq_event *ev) {
    xas_seq_event *current = seq->first,
                    *prev    = NULL;

    if (seq->first == NULL) {
        seq->first = ev;
        seq->last  = ev;

        return;
    }

    while (current) {
        xas_seq_event *next = current->next;

        if (timercmp(&ev->timestamp, &seq->last->timestamp, >=)) {
            seq->last->next = ev;
            seq->last       = ev;

            return;
        } else if (timercmp(&ev->timestamp, &current->timestamp, >)) {
            ev->next      = current->next;
            current->next = ev;

            return;
        } else if (prev && timercmp(&ev->timestamp, &prev->timestamp,    >)
                        && timercmp(&ev->timestamp, &current->timestamp, <=)) {
            prev->next = ev;
            ev->next   = current;

            return;
        } else if (prev && timercmp(&ev->timestamp, &prev->timestamp,       <=)
                        && timercmp(&ev->timestamp, &seq->first->timestamp, >)) {
            ev->next         = seq->first->next;
            seq->first->next = ev;

            return;
        } else if (timercmp(&ev->timestamp, &seq->first->timestamp, <=)) {
            ev->next   = seq->first;
            seq->first = ev;

            return;
        }

        prev    = current;
        current = next;
    }
}

int xas_seq_add_event_off(xas_seq *seq,
                            xas_spatial_object *object,
                            struct timeval timestamp) {
    xas_seq_event *ev;

    if ((ev = malloc(sizeof(*ev))) == NULL) {
        goto error_malloc_ev;
    }

    ev->type      = XAS_SEQ_EVENT_OFF;
    ev->objtype   = XAS_SEQ_OBJECT_ANY;
    ev->object    = object;
    ev->timestamp = timestamp;
    ev->next      = NULL;

    add_event(seq, ev);

    return 0;

error_malloc_ev:
    return -1;
}

int xas_seq_add_event_on(xas_seq *seq,
                           xas_spatial_object *object,
                           struct timeval timestamp) {
    xas_seq_event *ev;

    if ((ev = malloc(sizeof(*ev))) == NULL) {
        goto error_malloc_ev;
    }

    ev->type      = XAS_SEQ_EVENT_ON;
    ev->objtype   = XAS_SEQ_OBJECT_ANY;
    ev->object    = object;
    ev->timestamp = timestamp;
    ev->next      = NULL;

    add_event(seq, ev);

    return 0;

error_malloc_ev:
    return -1;
}

int xas_seq_add_set_position(xas_seq *seq,
                               xas_spatial_object *object,
                               struct timeval timestamp,
                               xas_spatial_coord point) {
    xas_seq_event *ev;

    if ((ev = malloc(sizeof(*ev))) == NULL) {
        goto error_malloc_ev;
    }

    ev->type      = XAS_SEQ_EVENT_SET_POSITION;
    ev->objtype   = XAS_SEQ_OBJECT_ANY;
    ev->object    = object;
    ev->timestamp = timestamp;
    ev->point     = point;
    ev->next      = NULL;

    add_event(seq, ev);

    return 0;

error_malloc_ev:
    return -1;
}

int xas_seq_add_set_heading(xas_seq *seq,
                              xas_spatial_object *object,
                              struct timeval timestamp,
                              xas_spatial_coord heading) {
    xas_seq_event *ev;

    if ((ev = malloc(sizeof(*ev))) == NULL) {
        goto error_malloc_ev;
    }

    ev->type      = XAS_SEQ_EVENT_SET_HEADING;
    ev->objtype   = XAS_SEQ_OBJECT_ANY;
    ev->object    = object;
    ev->timestamp = timestamp;
    ev->heading   = heading;
    ev->next      = NULL;

    add_event(seq, ev);

    return 0;

error_malloc_ev:
    return -1;
}

int xas_seq_add_set_speed(xas_seq *seq,
                            xas_spatial_object *object,
                            struct timeval timestamp,
                            float speed) {
    xas_seq_event *ev;

    if ((ev = malloc(sizeof(*ev))) == NULL) {
        goto error_malloc_ev;
    }

    ev->type      = XAS_SEQ_EVENT_SET_SPEED;
    ev->objtype   = XAS_SEQ_OBJECT_ANY;
    ev->object    = object;
    ev->timestamp = timestamp;
    ev->speed     = speed;
    ev->next      = NULL;

    add_event(seq, ev);

    return 0;

error_malloc_ev:
    return -1;
}

int xas_seq_add_set_gain(xas_seq *seq,
                           xas_spatial_object *object,
                           struct timeval timestamp,
                           float gain) {
    xas_seq_event *ev;

    if ((ev = malloc(sizeof(*ev))) == NULL) {
        goto error_malloc_ev;
    }

    ev->type      = XAS_SEQ_EVENT_ON;
    ev->objtype   = XAS_SEQ_OBJECT_ANY;
    ev->object    = object;
    ev->timestamp = timestamp;
    ev->gain      = gain;
    ev->next      = NULL;

    add_event(seq, ev);

    return 0;

error_malloc_ev:
    return -1;
}

int xas_seq_add_set_bank(xas_seq *seq,
                           xas_spatial_object *object,
                           struct timeval timestamp,
                           size_t index) {
    xas_seq_event *ev;

    if ((ev = malloc(sizeof(*ev))) == NULL) {
        goto error_malloc_ev;
    }

    ev->type      = XAS_SEQ_EVENT_SET_BANK_INDEX;
    ev->objtype   = XAS_SEQ_OBJECT_BANK_PLAYER;
    ev->object    = object;
    ev->timestamp = timestamp;
    ev->next      = NULL;
    ev->index     = index;

    add_event(seq, ev);

    return 0;

error_malloc_ev:
    return -1;
}

int xas_seq_add_set_player_flags(xas_seq *seq,
                                   xas_spatial_object *object,
                                   struct timeval timestamp,
                                   int flags) {
    xas_seq_event *ev;

    if ((ev = malloc(sizeof(*ev))) == NULL) {
        goto error_malloc_ev;
    }

    ev->type      = XAS_SEQ_EVENT_SET_PLAYER_FLAGS;
    ev->objtype   = XAS_SEQ_OBJECT_BANK_PLAYER;
    ev->object    = object;
    ev->timestamp = timestamp;
    ev->next      = NULL;
    ev->flags     = flags;

    add_event(seq, ev);

    return 0;

error_malloc_ev:
    return -1;
}

int xas_seq_add_set_synth_type(xas_seq *seq,
                                 xas_spatial_object *object,
                                 struct timeval timestamp,
                                 enum xas_synth_type type) {
    xas_seq_event *ev;

    if ((ev = malloc(sizeof(*ev))) == NULL) {
        goto error_malloc_ev;
    }

    ev->type       = XAS_SEQ_EVENT_SET_SYNTH_TYPE;
    ev->objtype    = XAS_SEQ_OBJECT_SYNTH;
    ev->object     = object;
    ev->timestamp  = timestamp;
    ev->next       = NULL;
    ev->synth_type = type;

    add_event(seq, ev);

    return 0;

error_malloc_ev:
    return -1;
}

int xas_seq_add_set_frequency(xas_seq *seq,
                                xas_spatial_object *object,
                                struct timeval timestamp,
                                size_t frequency) {
    xas_seq_event *ev;

    if ((ev = malloc(sizeof(*ev))) == NULL) {
        goto error_malloc_ev;
    }

    ev->type      = XAS_SEQ_EVENT_SET_FREQUENCY;
    ev->objtype   = XAS_SEQ_OBJECT_SYNTH;
    ev->object    = object;
    ev->timestamp = timestamp;
    ev->next      = NULL;
    ev->frequency = frequency;

    add_event(seq, ev);

    return 0;

error_malloc_ev:
    return -1;
}

int xas_seq_add_phrase(xas_seq *seq,
                         xas_spatial_object *object,
                         struct timeval timestamp,
                         const char *phrase) {
    xas_seq_event *ev;

    if ((ev = malloc(sizeof(*ev))) == NULL) {
        goto error_malloc_ev;
    }

    ev->type      = XAS_SEQ_EVENT_SPEECH;
    ev->objtype   = XAS_SEQ_OBJECT_VOX;
    ev->object    = object;
    ev->timestamp = timestamp;
    ev->next      = NULL;
    ev->phrase    = phrase;

    add_event(seq, ev);

    return 0;

error_malloc_ev:
    return -1;
}

static int event_trigger(xas_spatial_scene *scene, xas_seq_event *ev) {
    switch (ev->type) {
        case XAS_SEQ_EVENT_OFF:
            return xas_spatial_object_stop(ev->object);

        case XAS_SEQ_EVENT_ON:
            return xas_spatial_object_start(ev->object);

        case XAS_SEQ_EVENT_SET_POSITION:
            xas_spatial_scene_position_object(scene,
                                                ev->object,
                                                ev->point);

            break;

        case XAS_SEQ_EVENT_SET_HEADING:
            ev->object->heading = ev->heading;

            break;

        case XAS_SEQ_EVENT_SET_SPEED:
            ev->object->speed = ev->speed;

            break;

        case XAS_SEQ_EVENT_SET_GAIN:
            xas_object_set_gain(ev->object->ctx, ev->gain);

            break;

        case XAS_SEQ_EVENT_SET_FREQUENCY:
            if (ev->objtype != XAS_SEQ_OBJECT_SYNTH) {
                goto error_invalid_event;
            }

            xas_synth_set_frequency(ev->object->ctx, ev->frequency);

            break;

        case XAS_SEQ_EVENT_SET_SYNTH_TYPE:
            if (ev->objtype != XAS_SEQ_OBJECT_SYNTH) {
                goto error_invalid_event;
            }

            xas_synth_set_type(ev->object->ctx, ev->synth_type);

            break;

        case XAS_SEQ_EVENT_SET_BANK_INDEX:
            if (ev->objtype != XAS_SEQ_OBJECT_BANK_PLAYER) {
                goto error_invalid_event;
            }

            xas_bank_player_set_entry(ev->object->ctx, ev->index);

            break;

        case XAS_SEQ_EVENT_SET_PLAYER_FLAGS:
            if (ev->objtype != XAS_SEQ_OBJECT_BANK_PLAYER) {
                goto error_invalid_event;
            }

            xas_bank_player_set_flags(ev->object->ctx, ev->flags);

            break;

        case XAS_SEQ_EVENT_SPEECH:
            if (ev->objtype != XAS_SEQ_OBJECT_VOX) {
                goto error_invalid_event;
            }

            xas_vox_say(ev->object->ctx, ev->phrase);
            xas_vox_generate(ev->object->ctx);

            break;
    }

    return 0;

error_invalid_event:
    return -1;
}

static inline void timerupdate(struct timeval *tv,
                               suseconds_t interval,
                               size_t frame) {
    suseconds_t usec = frame * interval;

    tv->tv_sec  = usec / 1000000;
    tv->tv_usec = usec % 1000000;
}

int xas_seq_play(xas_seq *seq, xas_audio_stream *sink) {
    xas_seq_event *ev = seq->first;
    xas_audio_stream *source;

    size_t frame       = 0,
           sample_rate = seq->scene->format.sample_rate,
           buffer_size = seq->buffer_size;

    suseconds_t interval = 1000000 / (sample_rate / buffer_size);

    int16_t *samples;

    if ((source = xas_spatial_scene_stream_new(seq->scene,
                                                 seq->buffer_size)) == NULL) {
        goto error_spatial_scene_stream_new;
    }

    while (ev) {
        struct timeval tv;

        ssize_t readlen;

        timerupdate(&tv, interval, frame);

        while (ev && !timercmp(&tv, &ev->timestamp, <)) {
            if (event_trigger(seq->scene, ev) < 0) {
                goto error_event_trigger;
            }

            ev = ev->next;
        }

        if ((readlen = xas_audio_stream_read(source,
                                               (void **)&samples,
                                               buffer_size)) < 0) {
            goto error_audio_stream_io;
        } else if (readlen == 0) {
            break;
        }

        if (xas_audio_stream_write(sink, samples, readlen) < 0) {
            goto error_audio_stream_io;
        }

        frame++;
    }

    xas_audio_stream_destroy(source);

    return frame * buffer_size;

error_audio_stream_io:
error_event_trigger:
    xas_audio_stream_destroy(source);

error_spatial_scene_stream_new:
    return -1;
}