/*
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg 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
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #include <stdio.h>
 #include <string.h>
 
 #include "libavutil/hwcontext.h"
 #include "libavutil/hwcontext_opencl.h"
 #include "libavutil/mem.h"
 
 #include "avfilter.h"
 #include "formats.h"
 #include "opencl.h"
 
 int ff_opencl_filter_query_formats(AVFilterContext *avctx)
 {
     const static enum AVPixelFormat pix_fmts[] = {
         AV_PIX_FMT_OPENCL,
         AV_PIX_FMT_NONE,
     };
     AVFilterFormats *formats;
 
     formats = ff_make_format_list(pix_fmts);
     if (!formats)
         return AVERROR(ENOMEM);
 
     return ff_set_common_formats(avctx, formats);
 }
 
 int ff_opencl_filter_config_input(AVFilterLink *inlink)
 {
     AVFilterContext   *avctx = inlink->dst;
     OpenCLFilterContext *ctx = avctx->priv;
     AVHWFramesContext *input_frames;
 
     if (!inlink->hw_frames_ctx) {
         av_log(avctx, AV_LOG_ERROR, "OpenCL filtering requires a "
                "hardware frames context on the input.\n");
         return AVERROR(EINVAL);
     }
 
     // Extract the device and default output format from the first input.
     if (avctx->inputs[0] != inlink)
         return 0;
 
     input_frames = (AVHWFramesContext*)inlink->hw_frames_ctx->data;
 
     if (input_frames->format != AV_PIX_FMT_OPENCL)
         return AVERROR(EINVAL);
 
     ctx->device_ref = av_buffer_ref(input_frames->device_ref);
     if (!ctx->device_ref)
         return AVERROR(ENOMEM);
     ctx->device = input_frames->device_ctx;
     ctx->hwctx  = ctx->device->hwctx;
 
     // Default output parameters match input parameters.
     if (ctx->output_format == AV_PIX_FMT_NONE)
         ctx->output_format = input_frames->sw_format;
     if (!ctx->output_width)
         ctx->output_width  = inlink->w;
     if (!ctx->output_height)
         ctx->output_height = inlink->h;
 
     return 0;
 }
 
 int ff_opencl_filter_config_output(AVFilterLink *outlink)
 {
     AVFilterContext   *avctx = outlink->src;
     OpenCLFilterContext *ctx = avctx->priv;
     AVBufferRef       *output_frames_ref = NULL;
     AVHWFramesContext *output_frames;
     int err;
 
     av_buffer_unref(&outlink->hw_frames_ctx);
 
     output_frames_ref = av_hwframe_ctx_alloc(ctx->device_ref);
     if (!output_frames_ref) {
         err = AVERROR(ENOMEM);
         goto fail;
     }
     output_frames = (AVHWFramesContext*)output_frames_ref->data;
 
     output_frames->format    = AV_PIX_FMT_OPENCL;
     output_frames->sw_format = ctx->output_format;
     output_frames->width     = ctx->output_width;
     output_frames->height    = ctx->output_height;
 
     err = av_hwframe_ctx_init(output_frames_ref);
     if (err < 0) {
         av_log(avctx, AV_LOG_ERROR, "Failed to initialise output "
                "frames: %d.\n", err);
         goto fail;
     }
 
     outlink->hw_frames_ctx = output_frames_ref;
     outlink->w = ctx->output_width;
     outlink->h = ctx->output_height;
 
     return 0;
 fail:
     av_buffer_unref(&output_frames_ref);
     return err;
 }
 
 int ff_opencl_filter_init(AVFilterContext *avctx)
 {
     OpenCLFilterContext *ctx = avctx->priv;
 
     ctx->output_format = AV_PIX_FMT_NONE;
 
     return 0;
 }
 
 void ff_opencl_filter_uninit(AVFilterContext *avctx)
 {
     OpenCLFilterContext *ctx = avctx->priv;
     cl_int cle;
 
     if (ctx->program) {
         cle = clReleaseProgram(ctx->program);
         if (cle != CL_SUCCESS)
             av_log(avctx, AV_LOG_ERROR, "Failed to release "
                    "program: %d.\n", cle);
     }
 
     av_buffer_unref(&ctx->device_ref);
 }
 
 int ff_opencl_filter_load_program(AVFilterContext *avctx,
                                   const char **program_source_array,
                                   int nb_strings)
 {
     OpenCLFilterContext *ctx = avctx->priv;
     cl_int cle;
 
     ctx->program = clCreateProgramWithSource(ctx->hwctx->context, nb_strings,
                                              program_source_array,
                                              NULL, &cle);
     if (!ctx->program) {
         av_log(avctx, AV_LOG_ERROR, "Failed to create program: %d.\n", cle);
         return AVERROR(EIO);
     }
 
     cle = clBuildProgram(ctx->program, 1, &ctx->hwctx->device_id,
                          NULL, NULL, NULL);
     if (cle != CL_SUCCESS) {
         av_log(avctx, AV_LOG_ERROR, "Failed to build program: %d.\n", cle);
 
         if (cle == CL_BUILD_PROGRAM_FAILURE) {
             char *log;
             size_t log_length;
 
             clGetProgramBuildInfo(ctx->program, ctx->hwctx->device_id,
                                   CL_PROGRAM_BUILD_LOG, 0, NULL, &log_length);
 
             log = av_malloc(log_length);
             if (log) {
                 cle = clGetProgramBuildInfo(ctx->program,
                                             ctx->hwctx->device_id,
                                             CL_PROGRAM_BUILD_LOG,
                                             log_length, log, NULL);
                 if (cle == CL_SUCCESS)
                     av_log(avctx, AV_LOG_ERROR, "Build log:\n%s\n", log);
             }
 
             av_free(log);
         }
 
         clReleaseProgram(ctx->program);
         ctx->program = NULL;
         return AVERROR(EIO);
     }
 
     return 0;
 }
 
 int ff_opencl_filter_load_program_from_file(AVFilterContext *avctx,
                                             const char *filename)
 {
     FILE *file;
     char *src = NULL;
     size_t pos, len, rb;
     const char *src_const;
     int err;
 
     file = fopen(filename, "r");
     if (!file) {
         av_log(avctx, AV_LOG_ERROR, "Unable to open program "
                "source file \"%s\".\n", filename);
         return AVERROR(ENOENT);
     }
 
     len = 1 << 16;
     pos = 0;
 
     err = av_reallocp(&src, len);
     if (err < 0)
         goto fail;
 
     err = snprintf(src, len, "#line 1 \"%s\"\n", filename);
     if (err < 0) {
         err = AVERROR(errno);
         goto fail;
     }
     if (err > len / 2) {
         err = AVERROR(EINVAL);
         goto fail;
     }
     pos = err;
 
     while (1) {
         rb = fread(src + pos, 1, len - pos - 1, file);
         if (rb == 0 && ferror(file)) {
             err = AVERROR(EIO);
             goto fail;
         }
         pos += rb;
         if (pos < len)
             break;
         len <<= 1;
         err = av_reallocp(&src, len);
         if (err < 0)
             goto fail;
     }
     src[pos] = 0;
 
     src_const = src;
 
     err = ff_opencl_filter_load_program(avctx, &src_const, 1);
 fail:
     fclose(file);
     av_freep(&src);
     return err;
 }