/*
* Copyright (C) 2011 Doubango Telecom <http://www.doubango.org>
*
* Contact: Mamadou Diop <diopmamadou(at)doubango(DOT)org>
*	
* This file is part of Open Source Doubango Framework.
*
* DOUBANGO 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 3 of the License, or
* (at your option) any later version.
*	
* DOUBANGO 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 DOUBANGO.
*
*/

/**@file tdav_video_jb.c
 * @brief Video Jitter Buffer
 *
 * @author Mamadou Diop <diopmamadou(at)doubango(DOT)org>
 */
#include "tinydav/video/jb/tdav_video_jb.h"
#include "tinydav/video/jb/tdav_video_frame.h"

#include "tinyrtp/rtp/trtp_rtp_packet.h"

#include "tsk_time.h"
#include "tsk_memory.h"
#include "tsk_thread.h"
#include "tsk_condwait.h"
#include "tsk_debug.h"

#if TSK_UNDER_WINDOWS
#	include <windows.h>
#endif

// default frame rate
// the corret fps will be computed using the RTP timestamps
#define TDAV_VIDEO_JB_FPS		TDAV_VIDEO_JB_FPS_MAX
#define TDAV_VIDEO_JB_FPS_MIN	10
#define TDAV_VIDEO_JB_FPS_MAX	60
// Number of correct consecutive video frames to receive before computing the FPS
#define TDAV_VIDEO_JB_FPS_PROB	(TDAV_VIDEO_JB_FPS << 1)
// Maximum gap allowed (used to detect seqnum wrpping)
#define TDAV_VIDEO_JB_MAX_DROPOUT		0xFD9B

#define TDAV_VIDEO_JB_DISABLE           0

#define TDAV_VIDEO_JB_TAIL_MAX_LOG2		1
#if TDAV_UNDER_MOBILE /* to avoid too high memory usage */
#	define TDAV_VIDEO_JB_TAIL_MAX			(TDAV_VIDEO_JB_FPS_MIN << TDAV_VIDEO_JB_TAIL_MAX_LOG2)
#else
#	define TDAV_VIDEO_JB_TAIL_MAX			(TDAV_VIDEO_JB_FPS_MAX << TDAV_VIDEO_JB_TAIL_MAX_LOG2)
#endif

#define TDAV_VIDEO_JB_RATE				90 /* KHz */

#define TDAV_VIDEO_JB_LATENCY_MIN		2 /* Must be > 0 */
#define TDAV_VIDEO_JB_LATENCY_MAX		15 /* Default, will be updated using actual fps ((1000 / self->avg_duration)) */

static const tdav_video_frame_t* _tdav_video_jb_get_frame(struct tdav_video_jb_s* self, uint32_t timestamp, uint8_t pt, tsk_bool_t *pt_matched);
static void* TSK_STDCALL _tdav_video_jb_decode_thread_func(void *arg);

typedef struct tdav_video_jb_s
{
	TSK_DECLARE_OBJECT;

	tsk_bool_t started;
	int32_t fps;
	int32_t fps_prob;
	int32_t avg_duration;
	int32_t rate; // in Khz
	uint32_t last_timestamp;
	int32_t conseq_frame_drop;
	int32_t tail_max;
	tdav_video_frames_L_t *frames;
	int64_t frames_count;

	tsk_size_t latency_min;
	tsk_size_t latency_max;

	uint32_t decode_last_timestamp;
	int32_t decode_last_seq_num_with_mark; // -1 = unset
	uint64_t decode_last_time;
	tsk_thread_handle_t* decode_thread[1];
	tsk_condwait_handle_t* decode_thread_cond;

	uint16_t seq_nums[0xFF];
	tdav_video_jb_cb_f callback;
	const void* callback_data;

	// to avoid locking use different cb_data
	tdav_video_jb_cb_data_xt cb_data_rtp;
	tdav_video_jb_cb_data_xt cb_data_fdd;
	tdav_video_jb_cb_data_xt cb_data_any;

	struct{
		void* ptr;
		tsk_size_t size;
	} buffer;

	TSK_DECLARE_SAFEOBJ;
}
tdav_video_jb_t;


static tsk_object_t* tdav_video_jb_ctor(tsk_object_t * self, va_list * app)
{
	tdav_video_jb_t *jb = self;
	if(jb){
		if(!(jb->frames = tsk_list_create())){
			TSK_DEBUG_ERROR("Failed to create list");
			return tsk_null;
		}
		if(!(jb->decode_thread_cond = tsk_condwait_create())){
			TSK_DEBUG_ERROR("Failed to create condition var");
			return tsk_null;
		}
		jb->cb_data_fdd.type = tdav_video_jb_cb_data_type_fdd;
		jb->cb_data_rtp.type = tdav_video_jb_cb_data_type_rtp;

		jb->decode_last_seq_num_with_mark = -1;

		jb->fps = TDAV_VIDEO_JB_FPS_MAX;

		jb->rate = TDAV_VIDEO_JB_RATE;

		jb->latency_min = TDAV_VIDEO_JB_LATENCY_MIN;
		jb->latency_max = TDAV_VIDEO_JB_LATENCY_MAX;

		tsk_safeobj_init(jb);
	}
	return self;
}
static tsk_object_t* tdav_video_jb_dtor(tsk_object_t * self)
{ 
	tdav_video_jb_t *jb = self;
	if(jb){
		if(jb->started){
			tdav_video_jb_stop(jb);
		}
		TSK_OBJECT_SAFE_FREE(jb->frames);
		if(jb->decode_thread_cond){
			tsk_condwait_destroy(&jb->decode_thread_cond);
		}
		TSK_SAFE_FREE(jb->buffer.ptr);
		tsk_safeobj_deinit(jb);
	}

	return self;
}
static const tsk_object_def_t tdav_video_jb_def_s = 
{
	sizeof(tdav_video_jb_t),
	tdav_video_jb_ctor, 
	tdav_video_jb_dtor,
	tsk_null, 
};

tdav_video_jb_t* tdav_video_jb_create()
{
	tdav_video_jb_t* jb;

	if((jb = tsk_object_new(&tdav_video_jb_def_s))){
		jb->fps = TDAV_VIDEO_JB_FPS;
		jb->fps_prob = TDAV_VIDEO_JB_FPS_PROB;
		jb->tail_max = TDAV_VIDEO_JB_TAIL_MAX;
	}
	return jb;
}

#define tdav_video_jb_reset_fps_prob(self) {\
	(self)->fps_prob = TDAV_VIDEO_JB_FPS_PROB; \
	(self)->last_timestamp = 0; \
	(self)->avg_duration = 0; \
}
#define tdav_video_jb_reset_tail_min_prob(self) {\
	(self)->tail_prob = TDAV_VIDEO_JB_TAIL_MIN_PROB; \
	(self)->tail_min = TDAV_VIDEO_JB_TAIL_MIN_MAX; \
}

int tdav_video_jb_set_callback(tdav_video_jb_t* self, tdav_video_jb_cb_f callback, const void* usr_data)
{
	if(!self){
		TSK_DEBUG_ERROR("Invalid parameter");
		return -1;
	}
	self->callback = callback;
	self->cb_data_any.usr_data = usr_data;
	self->cb_data_fdd.usr_data = usr_data;
	self->cb_data_rtp.usr_data = usr_data;
	return 0;
}

int tdav_video_jb_start(tdav_video_jb_t* self)
{
	int ret = 0;
	if(!self){
		TSK_DEBUG_ERROR("Invalid parameter");
		return -1;
	}
	if(self->started){
		return 0;
	}

	self->started = tsk_true;

	if(!self->decode_thread[0]){
		ret = tsk_thread_create(&self->decode_thread[0], _tdav_video_jb_decode_thread_func, self);
		if(ret != 0 || !self->decode_thread[0]){
			TSK_DEBUG_ERROR("Failed to create new thread");
		}
		ret = tsk_thread_set_priority(self->decode_thread[0], TSK_THREAD_PRIORITY_TIME_CRITICAL);
	}
	
	return ret;
}

int tdav_video_jb_put(tdav_video_jb_t* self, trtp_rtp_packet_t* rtp_pkt)
{
#if TDAV_VIDEO_JB_DISABLE
    self->cb_data_rtp.rtp.pkt = rtp_pkt;
    self->callback(&self->cb_data_rtp);
#else
	const tdav_video_frame_t* old_frame;
	tsk_bool_t pt_matched = tsk_false, is_frame_late_or_dup = tsk_false, is_restarted = tsk_false;
	uint16_t* seq_num;

	if(!self || !rtp_pkt || !rtp_pkt->header){
		TSK_DEBUG_ERROR("Invalid parameter");
		return -1;
	}

	if(!self->started){
		TSK_DEBUG_INFO("Video jitter buffer not started");
		return 0;
	}

	seq_num = &self->seq_nums[rtp_pkt->header->payload_type];

	tsk_safeobj_lock(self);

	//TSK_DEBUG_INFO("receive seqnum=%u", rtp_pkt->header->seq_num);

	if(self->decode_last_timestamp && (self->decode_last_timestamp > rtp_pkt->header->timestamp)){
		if((self->decode_last_timestamp - rtp_pkt->header->timestamp) < TDAV_VIDEO_JB_MAX_DROPOUT){
			TSK_DEBUG_INFO("--------Frame already Decoded [seqnum=%u]------------", rtp_pkt->header->seq_num);
			tsk_safeobj_unlock(self);
			return 0;
		}
	}

	old_frame = _tdav_video_jb_get_frame(self, rtp_pkt->header->timestamp, rtp_pkt->header->payload_type, &pt_matched);	

	if((*seq_num && *seq_num != 0xFFFF) && (*seq_num + 1) != rtp_pkt->header->seq_num){
		int32_t diff = ((int32_t)rtp_pkt->header->seq_num - (int32_t)*seq_num);
		tsk_bool_t is_frame_loss = (diff > 0);
		is_restarted = (TSK_ABS(diff) > TDAV_VIDEO_JB_MAX_DROPOUT);
		is_frame_late_or_dup = !is_frame_loss;
		tdav_video_jb_reset_fps_prob(self);
		TSK_DEBUG_INFO("Packet %s (from JB) [%hu - %hu]", is_frame_loss ? "loss" : "late/duplicated/nack", *seq_num, rtp_pkt->header->seq_num);
		
		if(is_frame_loss && !is_restarted){
			if(self->callback){			
				self->cb_data_any.type = tdav_video_jb_cb_data_type_fl;
				self->cb_data_any.ssrc = rtp_pkt->header->ssrc;
				self->cb_data_any.fl.seq_num = (*seq_num + 1);
				self->cb_data_any.fl.count = diff - 1;
				self->callback(&self->cb_data_any);
			}
		}
	}

	if(!old_frame){
		tdav_video_frame_t* new_frame;
		if(pt_matched){
			// if we have a frame with the same payload type but without this timestamp this means that we moved to a new frame
			// this happens if the frame is waiting to be decoded or the marker is lost
		}
		if((new_frame = tdav_video_frame_create(rtp_pkt))){
			// compute avg frame duration
			if(self->last_timestamp && self->last_timestamp < rtp_pkt->header->timestamp){
				uint32_t duration = (rtp_pkt->header->timestamp - self->last_timestamp)/self->rate;
				self->avg_duration = self->avg_duration ? ((self->avg_duration + duration) >> 1) : duration;
				--self->fps_prob;
			}
			self->last_timestamp = rtp_pkt->header->timestamp;
			
			tsk_list_lock(self->frames);
			if(self->frames_count >= self->tail_max){
				if(++self->conseq_frame_drop >= self->tail_max){
					TSK_DEBUG_ERROR("Too many frames dropped and fps=%d", self->fps);
					tsk_list_clear_items(self->frames);
					self->conseq_frame_drop = 0;
					self->frames_count = 1;
					if(self->callback){
						self->cb_data_any.type = tdav_video_jb_cb_data_type_tmfr;
						self->cb_data_any.ssrc = rtp_pkt->header->ssrc;
						self->callback(&self->cb_data_any);
					}
				}
				else{
					TSK_DEBUG_INFO("Dropping video frame because frames_count(%lld)>=tail_max(%d)", self->frames_count, self->tail_max);
					tsk_list_remove_first_item(self->frames);
				}
				tdav_video_jb_reset_fps_prob(self);
			}
			else{
				++self->frames_count;
			}
			tsk_list_push_ascending_data(self->frames, (void**)&new_frame);
			tsk_list_unlock(self->frames);
		}
		if(self->fps_prob <= 0 && self->avg_duration){
			// compute FPS using timestamp values
			int32_t fps_new = (1000 / self->avg_duration);
			int32_t fps_old = self->fps;
			self->fps = TSK_CLAMP(TDAV_VIDEO_JB_FPS_MIN, fps_new, TDAV_VIDEO_JB_FPS_MAX);
                        // Maximum of 2 seconds data (fps * 2) is stored in JB
			self->tail_max = (self->fps << TDAV_VIDEO_JB_TAIL_MAX_LOG2); // maximum delay = 2 seconds
                        // Minimum number of frames required to start decoding, reset based on actual calculated fps
			self->latency_max = self->fps; // maximum = 1 second
			TSK_DEBUG_INFO("According to rtp-timestamps ...FPS = %d (clipped to %d) tail_max=%d, latency_max=%u", fps_new, self->fps, self->tail_max, self->latency_max);
			tdav_video_jb_reset_fps_prob(self);
		}
	}
	else{
		tdav_video_frame_put((tdav_video_frame_t*)old_frame, rtp_pkt);
	}

	tsk_safeobj_unlock(self);

	if(!is_frame_late_or_dup || is_restarted){
		*seq_num = rtp_pkt->header->seq_num;
	}
#endif

	return 0;
}

int tdav_video_jb_stop(tdav_video_jb_t* self)
{
	int ret;
	if(!self){
		TSK_DEBUG_ERROR("Invalid parameter");
		return -1;
	}
	if(!self->started){
		return 0;
	}

	TSK_DEBUG_INFO("tdav_video_jb_stop()");

	self->started = tsk_false;

	ret = tsk_condwait_broadcast(self->decode_thread_cond);
	
	if(self->decode_thread[0]){
		ret = tsk_thread_join(&self->decode_thread[0]);
	}
	
	return ret;
}

static const tdav_video_frame_t* _tdav_video_jb_get_frame(tdav_video_jb_t* self, uint32_t timestamp, uint8_t pt, tsk_bool_t *pt_matched)
{
	const tdav_video_frame_t* ret = tsk_null;
	const tsk_list_item_t *item;
	
	*pt_matched =tsk_false;

	tsk_list_lock(self->frames);
	tsk_list_foreach(item, self->frames){
		if(TDAV_VIDEO_FRAME(item->data)->payload_type == pt){
			if(!(*pt_matched)) *pt_matched = tsk_true;
			if(TDAV_VIDEO_FRAME(item->data)->timestamp == timestamp){
				ret = item->data;
				break;
			}
		}
		
	}
	tsk_list_unlock(self->frames);

	return ret;
}

static void* TSK_STDCALL _tdav_video_jb_decode_thread_func(void *arg)
{
	tdav_video_jb_t* jb = (tdav_video_jb_t*)arg;
	uint64_t delay;
	uint16_t missing_seq_num_start = 0, prev_missing_seq_num_start = 0;
	tsk_size_t missing_seq_num_count = 0, prev_lasted_missing_seq_num_count = 0;
	const tdav_video_frame_t* frame;
	tsk_list_item_t* item;
	uint64_t next_decode_duration = (1000 / jb->fps), now;
	uint64_t x_decode_duration = (1000 / jb->fps); // expected
	uint64_t x_decode_time = tsk_time_now();//expected
	tsk_bool_t postpone;
	static const uint64_t __toomuch_delay_to_be_valid = 10000; // guard against systems with buggy "tsk_time_now()" -Won't say Windows ...but :)-

	jb->decode_last_seq_num_with_mark = -1; // -1 -> unset
	jb->decode_last_time = tsk_time_now();

	(void)(now);
	(void)(delay);
	
	TSK_DEBUG_INFO("Video jitter buffer thread - ENTER");

	while(jb->started){
		tsk_condwait_timedwait(jb->decode_thread_cond, next_decode_duration);

		if(!jb->started){
			break;
		}

		//TSK_DEBUG_INFO("Frames count = %ld" , (long)jb->frames_count);

		if(jb->frames_count >= (int64_t)jb->latency_min){
			item = tsk_null;
			postpone = tsk_false;
            
			tsk_safeobj_lock(jb); // against get_frame()
			tsk_list_lock(jb->frames); // against put()
			
			// is it still acceptable to wait for missing packets?
			if (jb->frames_count < (int64_t)jb->latency_max){
				frame = (const tdav_video_frame_t*)jb->frames->head->data;
				if(!tdav_video_frame_is_complete(frame, jb->decode_last_seq_num_with_mark, &missing_seq_num_start, &missing_seq_num_count)){
					TSK_DEBUG_INFO("Time to decode frame...but some RTP packets are missing (missing_seq_num_start=%hu, missing_seq_num_count=%u, last_seq_num_with_mark=%d).", missing_seq_num_start, missing_seq_num_count, jb->decode_last_seq_num_with_mark);
					// signal to the session that a sequence number is missing (will send a NACK)
					// the missing seqnum has been already requested in jb_put() and here we request it again only ONE time
					if(jb->callback){
						if(prev_missing_seq_num_start != missing_seq_num_start || prev_lasted_missing_seq_num_count != missing_seq_num_count){ // guard to request it only once
							jb->cb_data_any.type = tdav_video_jb_cb_data_type_fl;
							jb->cb_data_any.ssrc = frame->ssrc;
							jb->cb_data_any.fl.seq_num = prev_missing_seq_num_start = missing_seq_num_start;
							jb->cb_data_any.fl.count = prev_lasted_missing_seq_num_count = missing_seq_num_count;
							jb->callback(&jb->cb_data_any);
						}
						postpone = tsk_true;
					}
				}
			}
			else{
				TSK_DEBUG_INFO("frames_count(%lld)>=latency_max(%u)...decoding video frame even if pkts are missing :(", jb->frames_count, jb->latency_max);
				jb->decode_last_seq_num_with_mark = -1; // unset()
			}
			if(!postpone){
				item = tsk_list_pop_first_item(jb->frames);
				--jb->frames_count;
			}
			tsk_list_unlock(jb->frames);
			tsk_safeobj_unlock(jb);
            
			if(item){
				jb->decode_last_timestamp = ((const tdav_video_frame_t*)item->data)->timestamp;
				if(jb->callback){
					trtp_rtp_packet_t* pkt;
					const tsk_list_item_t* _item = item; // save memory address as "tsk_list_foreach() will change it for each loop"
					int32_t last_seq_num = -1; // guard against duplicated packets
					frame = _item->data;
					tsk_list_foreach(_item, frame->pkts){
						if(!(pkt = _item->data) || !pkt->payload.size || !pkt->header || pkt->header->seq_num == last_seq_num || !jb->started){
							TSK_DEBUG_ERROR("Skipping invalid rtp packet (do not decode!)");
							continue;
						}					
						jb->cb_data_rtp.rtp.pkt = pkt;
						jb->callback(&jb->cb_data_rtp);
						if(pkt->header->marker){
							jb->decode_last_seq_num_with_mark = pkt->header->seq_num;
						}
					}
				}
	            
				TSK_OBJECT_SAFE_FREE(item);
			}
		}
		
#if 1
		now = tsk_time_now();
		if (jb->frames_count > (int64_t)jb->latency_max){
			x_decode_time = now;
			next_decode_duration = 0;
		}
		else{
			delay = ( (now > x_decode_time) ? (now - x_decode_time) : (x_decode_duration >> 1)/* do not use zero to avoid endless loop when there is no frame to display */ );
			next_decode_duration = (delay > x_decode_duration) ? 0 : (x_decode_duration - delay);
			x_decode_duration = (1000 / jb->fps);
			x_decode_time += x_decode_duration;
		}
		

		//TSK_DEBUG_INFO("next_decode_timeout=%llu, delay = %llu", next_decode_duration, delay);
#else
		next_decode_duration = (1000 / jb->fps);
#endif
	}

	TSK_DEBUG_INFO("Video jitter buffer thread - EXIT");

	return tsk_null;
}
