/*
 * This file is part of mpv.
 *
 * mpv is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * mpv 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.
 *
 * You should have received a copy of the GNU General Public License along
 * with mpv.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <assert.h>

#include <va/va.h>
#include <va/va_vpp.h>

#include "config.h"
#include "options/options.h"
#include "vf.h"
#include "video/vaapi.h"
#include "video/hwdec.h"
#include "video/mp_image_pool.h"

static bool check_error(struct vf_instance *vf, VAStatus status, const char *msg)
{
    if (status == VA_STATUS_SUCCESS)
        return true;
    MP_ERR(vf, "%s: %s\n", msg, vaErrorStr(status));
    return false;
}

struct surface_refs {
    VASurfaceID *surfaces;
    int num_surfaces;
};

static void add_surface(void *ta_ctx, struct surface_refs *refs, struct mp_image *s)
{
    VASurfaceID id = va_surface_id(s);
    if (id != VA_INVALID_ID)
        MP_TARRAY_APPEND(ta_ctx, refs->surfaces, refs->num_surfaces, id);
}

struct pipeline {
    VABufferID *filters;
    int num_filters;
    VAProcColorStandardType input_colors[VAProcColorStandardCount];
    VAProcColorStandardType output_colors[VAProcColorStandardCount];
    int num_input_colors, num_output_colors;
    struct surface_refs forward, backward;
};

struct vf_priv_s {
    int deint_type; // 0: none, 1: discard, 2: double fps
    bool do_deint;
    VABufferID buffers[VAProcFilterCount];
    int num_buffers;
    VAConfigID config;
    VAContextID context;
    struct mp_image_params params;
    VADisplay display;
    struct mp_vaapi_ctx *va;
    struct pipeline pipe;
    struct mp_image_pool *pool;
    int current_rt_format;

    int needed_future_frames;
    int needed_past_frames;

    // Queue of input frames, used to determine past/current/future frames.
    // queue[0] is the newest frame, queue[num_queue - 1] the oldest.
    struct mp_image **queue;
    int num_queue;
    // queue[current_pos] is the current frame, unless current_pos is not a
    // valid index.
    int current_pos;
};

static const struct vf_priv_s vf_priv_default = {
    .config = VA_INVALID_ID,
    .context = VA_INVALID_ID,
    .deint_type = 2,
};

// The array items must match with the "deint" suboption values.
static const int deint_algorithm[] = {
    [0] = VAProcDeinterlacingNone,
    [1] = VAProcDeinterlacingNone, // first-field, special-cased
    [2] = VAProcDeinterlacingBob,
    [3] = VAProcDeinterlacingWeave,
    [4] = VAProcDeinterlacingMotionAdaptive,
    [5] = VAProcDeinterlacingMotionCompensated,
};

static void flush_frames(struct vf_instance *vf)
{
    struct vf_priv_s *p = vf->priv;
    for (int n = 0; n < p->num_queue; n++)
        talloc_free(p->queue[n]);
    p->num_queue = 0;
    p->current_pos = -1;
}

static bool update_pipeline(struct vf_instance *vf, bool deint)
{
    struct vf_priv_s *p = vf->priv;
    VABufferID *filters = p->buffers;
    int num_filters = p->num_buffers;
    if (p->deint_type && !deint) {
        filters++;
        num_filters--;
    }
    if (filters == p->pipe.filters && num_filters == p->pipe.num_filters)
        return true;
    p->pipe.forward.num_surfaces = p->pipe.backward.num_surfaces = 0;
    p->pipe.num_input_colors = p->pipe.num_output_colors = 0;
    p->pipe.num_filters = 0;
    p->pipe.filters = NULL;
    if (!num_filters)
        return false;
    VAProcPipelineCaps caps;
    caps.input_color_standards = p->pipe.input_colors;
    caps.output_color_standards = p->pipe.output_colors;
    caps.num_input_color_standards = VAProcColorStandardCount;
    caps.num_output_color_standards = VAProcColorStandardCount;
    VAStatus status = vaQueryVideoProcPipelineCaps(p->display, p->context,
                                                   filters, num_filters, &caps);
    if (!check_error(vf, status, "vaQueryVideoProcPipelineCaps()"))
        return false;
    p->pipe.filters = filters;
    p->pipe.num_filters = num_filters;
    p->pipe.num_input_colors = caps.num_input_color_standards;
    p->pipe.num_output_colors = caps.num_output_color_standards;
    p->needed_future_frames = caps.num_forward_references;
    p->needed_past_frames = caps.num_backward_references;
    return true;
}

static inline int get_deint_field(struct vf_priv_s *p, int i,
                                  struct mp_image *mpi)
{
    if (!p->do_deint || !(mpi->fields & MP_IMGFIELD_INTERLACED))
        return VA_FRAME_PICTURE;
    return !!(mpi->fields & MP_IMGFIELD_TOP_FIRST) ^ i ? VA_TOP_FIELD : VA_BOTTOM_FIELD;
}

static struct mp_image *render(struct vf_instance *vf, struct mp_image *in,
                               unsigned int flags)
{
    struct vf_priv_s *p = vf->priv;
    VASurfaceID in_id = va_surface_id(in);
    if (!p->pipe.filters || in_id == VA_INVALID_ID)
        return NULL;

    struct mp_image *img = mp_image_pool_get(p->pool, IMGFMT_VAAPI, in->w, in->h);
    if (!img)
        return NULL;

    bool need_end_picture = false;
    bool success = false;

    VASurfaceID id = va_surface_id(img);
    if (id == VA_INVALID_ID)
        goto cleanup;

    VAStatus status = vaBeginPicture(p->display, p->context, id);
    if (!check_error(vf, status, "vaBeginPicture()"))
        goto cleanup;

    need_end_picture = true;

    VABufferID buffer = VA_INVALID_ID;
    VAProcPipelineParameterBuffer *param = NULL;
    status = vaCreateBuffer(p->display, p->context,
                            VAProcPipelineParameterBufferType,
                            sizeof(*param), 1, NULL, &buffer);
    if (!check_error(vf, status, "vaCreateBuffer()"))
        goto cleanup;

    VAProcFilterParameterBufferDeinterlacing *filter_params;
    status = vaMapBuffer(p->display, *(p->pipe.filters), (void**)&filter_params);
    if (!check_error(vf, status, "vaMapBuffer()"))
        goto cleanup;

    filter_params->flags = flags & VA_TOP_FIELD ? 0 : VA_DEINTERLACING_BOTTOM_FIELD;
    if (!(in->fields & MP_IMGFIELD_TOP_FIRST))
        filter_params->flags |= VA_DEINTERLACING_BOTTOM_FIELD_FIRST;

    vaUnmapBuffer(p->display, *(p->pipe.filters));

    status = vaMapBuffer(p->display, buffer, (void**)&param);
    if (!check_error(vf, status, "vaMapBuffer()"))
        goto cleanup;

    param->surface = in_id;
    param->surface_region = NULL;
    param->output_region = NULL;
    param->output_background_color = 0;
    param->filter_flags = flags;
    param->filters = p->pipe.filters;
    param->num_filters = p->pipe.num_filters;

    for (int n = 0; n < p->needed_future_frames; n++) {
        int idx = p->current_pos - 1 - n;
        if (idx >= 0 && idx < p->num_queue)
            add_surface(p, &p->pipe.forward, p->queue[idx]);
    }
    param->forward_references = p->pipe.forward.surfaces;
    param->num_forward_references = p->pipe.forward.num_surfaces;

    for (int n = 0; n < p->needed_past_frames; n++) {
        int idx = p->current_pos + 1 + n;
        if (idx >= 0 && idx < p->num_queue)
            add_surface(p, &p->pipe.backward, p->queue[idx]);
    }
    param->backward_references = p->pipe.backward.surfaces;
    param->num_backward_references = p->pipe.backward.num_surfaces;

    vaUnmapBuffer(p->display, buffer);

    status = vaRenderPicture(p->display, p->context, &buffer, 1);
    if (!check_error(vf, status, "vaRenderPicture()"))
        goto cleanup;

    success = true;

cleanup:
    if (need_end_picture)
        vaEndPicture(p->display, p->context);
    if (success)
        return img;
    talloc_free(img);
    return NULL;
}

static void output_frames(struct vf_instance *vf)
{
    struct vf_priv_s *p = vf->priv;

    struct mp_image *in = p->queue[p->current_pos];
    double prev_pts = p->current_pos + 1 < p->num_queue
        ? p->queue[p->current_pos + 1]->pts : MP_NOPTS_VALUE;

    bool deint = p->do_deint && p->deint_type > 0;
    if (!update_pipeline(vf, deint) || !p->pipe.filters) { // no filtering
        vf_add_output_frame(vf, mp_image_new_ref(in));
        return;
    }
    unsigned int csp = va_get_colorspace_flag(p->params.colorspace);
    unsigned int field = get_deint_field(p, 0, in);
    struct mp_image *out1 = render(vf, in, field | csp);
    if (!out1) { // cannot render
        vf_add_output_frame(vf, mp_image_new_ref(in));
        return;
    }
    mp_image_copy_attributes(out1, in);
    vf_add_output_frame(vf, out1);
    // first-field only
    if (field == VA_FRAME_PICTURE || (p->do_deint && p->deint_type < 2))
        return;
    double add = (in->pts - prev_pts) * 0.5;
    if (prev_pts == MP_NOPTS_VALUE || add <= 0.0 || add > 0.5) // no pts, skip it
        return;
    struct mp_image *out2 = render(vf, in, get_deint_field(p, 1, in) | csp);
    if (!out2) // cannot render
        return;
    mp_image_copy_attributes(out2, in);
    out2->pts = in->pts + add;
    vf_add_output_frame(vf, out2);
    return;
}

static struct mp_image *upload(struct vf_instance *vf, struct mp_image *in)
{
    struct vf_priv_s *p = vf->priv;
    struct mp_image *out = mp_image_pool_get(p->pool, IMGFMT_VAAPI, in->w, in->h);
    if (!out)
        return NULL;
    if (va_surface_upload(out, in) < 0) {
        talloc_free(out);
        return NULL;
    }
    mp_image_copy_attributes(out, in);
    return out;
}

static int filter_ext(struct vf_instance *vf, struct mp_image *in)
{
    struct vf_priv_s *p = vf->priv;

    if (in) {
        int rt_format = in->imgfmt == IMGFMT_VAAPI ? va_surface_rt_format(in)
                                                   : VA_RT_FORMAT_YUV420;
        if (!p->pool || p->current_rt_format != rt_format) {
            talloc_free(p->pool);
            p->pool = mp_image_pool_new(20);
            va_pool_set_allocator(p->pool, p->va, rt_format);
            p->current_rt_format = rt_format;
        }
        if (in->imgfmt != IMGFMT_VAAPI) {
            struct mp_image *tmp = upload(vf, in);
            talloc_free(in);
            in = tmp;
            if (!in)
                return -1;
        }
    }

    if (in) {
        MP_TARRAY_INSERT_AT(p, p->queue, p->num_queue, 0, in);
        p->current_pos++;
        assert(p->num_queue != 1 || p->current_pos == 0);
    }

    // Discard unneeded past frames.
    // Note that we keep at least 1 past frame (for PTS calculations).
    while (p->num_queue - (p->current_pos + 1) > MPMAX(p->needed_past_frames, 1)) {
        assert(p->num_queue > 0);
        talloc_free(p->queue[p->num_queue - 1]);
        p->num_queue--;
    }

    if (p->current_pos < p->needed_future_frames && in)
        return 0; // wait until future frames have been filled

    if (p->current_pos >= 0 && p->current_pos < p->num_queue) {
        output_frames(vf);
        p->current_pos--;
    }
    return 0;
}

static int reconfig(struct vf_instance *vf, struct mp_image_params *in,
                    struct mp_image_params *out)
{
    struct vf_priv_s *p = vf->priv;

    p->params = *in;
    *out = *in;
    out->imgfmt = IMGFMT_VAAPI;
    flush_frames(vf);
    return 0;
}

static void uninit(struct vf_instance *vf)
{
    struct vf_priv_s *p = vf->priv;
    for (int i = 0; i < p->num_buffers; i++)
        vaDestroyBuffer(p->display, p->buffers[i]);
    if (p->context != VA_INVALID_ID)
        vaDestroyContext(p->display, p->context);
    if (p->config != VA_INVALID_ID)
        vaDestroyConfig(p->display, p->config);
    talloc_free(p->pool);
    flush_frames(vf);
}

static int query_format(struct vf_instance *vf, unsigned int imgfmt)
{
    struct vf_priv_s *p = vf->priv;
    if (imgfmt == IMGFMT_VAAPI || va_image_format_from_imgfmt(p->va, imgfmt))
        return vf_next_query_format(vf, IMGFMT_VAAPI);
    return 0;
}

static int control(struct vf_instance *vf, int request, void* data)
{
    struct vf_priv_s *p = vf->priv;
    switch (request){
    case VFCTRL_GET_DEINTERLACE:
        *(int*)data = !!p->do_deint;
        return true;
    case VFCTRL_SET_DEINTERLACE:
        p->do_deint = *(int*)data;
        return true;
    case VFCTRL_SEEK_RESET:
        flush_frames(vf);
        return true;
    default:
        return CONTROL_UNKNOWN;
    }
}

static int va_query_filter_caps(struct vf_instance *vf, VAProcFilterType type,
                                void *caps, unsigned int count)
{
    struct vf_priv_s *p = vf->priv;
    VAStatus status = vaQueryVideoProcFilterCaps(p->display, p->context, type,
                                                 caps, &count);
    return check_error(vf, status, "vaQueryVideoProcFilterCaps()") ? count : 0;
}

static VABufferID va_create_filter_buffer(struct vf_instance *vf, int bytes,
                                          int num, void *data)
{
    struct vf_priv_s *p = vf->priv;
    VABufferID buffer;
    VAStatus status = vaCreateBuffer(p->display, p->context,
                                     VAProcFilterParameterBufferType,
                                     bytes, num, data, &buffer);
    return check_error(vf, status, "vaCreateBuffer()") ? buffer : VA_INVALID_ID;
}

static bool initialize(struct vf_instance *vf)
{
    struct vf_priv_s *p = vf->priv;
    VAStatus status;

    VAConfigID config;
    status = vaCreateConfig(p->display, VAProfileNone, VAEntrypointVideoProc,
                            NULL, 0, &config);
    if (!check_error(vf, status, "vaCreateConfig()")) // no entrypoint for video porc
        return false;
    p->config = config;

    VAContextID context;
    status = vaCreateContext(p->display, p->config, 0, 0, 0, NULL, 0, &context);
    if (!check_error(vf, status, "vaCreateContext()"))
        return false;
    p->context = context;

    VAProcFilterType filters[VAProcFilterCount];
    int num_filters = VAProcFilterCount;
    status = vaQueryVideoProcFilters(p->display, p->context, filters, &num_filters);
    if (!check_error(vf, status, "vaQueryVideoProcFilters()"))
        return false;

    VABufferID buffers[VAProcFilterCount];
    for (int i = 0; i < VAProcFilterCount; i++)
        buffers[i] = VA_INVALID_ID;
    for (int i = 0; i < num_filters; i++) {
        if (filters[i] == VAProcFilterDeinterlacing) {
            if (p->deint_type < 2)
                continue;
            VAProcFilterCapDeinterlacing caps[VAProcDeinterlacingCount];
            int num = va_query_filter_caps(vf, VAProcFilterDeinterlacing, caps,
                                           VAProcDeinterlacingCount);
            if (!num)
                continue;
            VAProcDeinterlacingType algorithm = deint_algorithm[p->deint_type];
            for (int n=0; n < num; n++) { // find the algorithm
                if (caps[n].type != algorithm)
                    continue;
                VAProcFilterParameterBufferDeinterlacing param;
                param.type = VAProcFilterDeinterlacing;
                param.algorithm = algorithm;
                buffers[VAProcFilterDeinterlacing] =
                    va_create_filter_buffer(vf, sizeof(param), 1, &param);
            }
            if (buffers[VAProcFilterDeinterlacing] == VA_INVALID_ID)
                MP_WARN(vf, "Selected deinterlacing algorithm not supported.\n");
        } // check other filters
    }
    p->num_buffers = 0;
    if (buffers[VAProcFilterDeinterlacing] != VA_INVALID_ID)
        p->buffers[p->num_buffers++] = buffers[VAProcFilterDeinterlacing];
    p->do_deint = !!p->deint_type;
    // next filters: p->buffers[p->num_buffers++] = buffers[next_filter];
    return true;
}

static int vf_open(vf_instance_t *vf)
{
    vf->reconfig = reconfig;
    vf->filter_ext = filter_ext;
    vf->query_format = query_format;
    vf->uninit = uninit;
    vf->control = control;

    struct vf_priv_s *p = vf->priv;
    if (!vf->hwdec)
        return false;
    hwdec_request_api(vf->hwdec, "vaapi");
    p->va = vf->hwdec->hwctx ? vf->hwdec->hwctx->vaapi_ctx : NULL;
    if (!p->va || !p->va->display)
        return false;
    p->display = p->va->display;
    if (initialize(vf))
        return true;
    uninit(vf);
    return false;
}

#define OPT_BASE_STRUCT struct vf_priv_s
static const m_option_t vf_opts_fields[] = {
    OPT_CHOICE("deint", deint_type, 0,
               // The values must match with deint_algorithm[].
               ({"no", 0},
                {"first-field", 1},
                {"bob", 2},
                {"weave", 3},
                {"motion-adaptive", 4},
                {"motion-compensated", 5})),
    {0}
};

const vf_info_t vf_info_vaapi = {
    .description = "VA-API Video Post-Process Filter",
    .name = "vavpp",
    .open = vf_open,
    .priv_size = sizeof(struct vf_priv_s),
    .priv_defaults = &vf_priv_default,
    .options = vf_opts_fields,
};