#include "metafile.h"
#include <glib.h>
#include <pthread.h>
#include <sys/types.h>
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>
#include <limits.h>
#include "log.h"
#include "stream.h"
#include "garbage.h"
#include "main.h"
#include "recaux.h"
#include "packet.h"


static pthread_mutex_t metafiles_lock = PTHREAD_MUTEX_INITIALIZER;
static GHashTable *metafiles;

//static pcre_t stream_interface_re,
	      //stream_details_re;


static void meta_free(void *ptr) {
	metafile_t *mf = ptr;

	dbg("freeing metafile info for %s", mf->name);
	g_string_chunk_free(mf->gsc);
	for (int i = 0; i < mf->streams->len; i++) {
		stream_t *stream = g_ptr_array_index(mf->streams, i);
		stream_close(stream); // should be closed already
		stream_free(stream);
	}
	g_ptr_array_free(mf->streams, TRUE);
	g_slice_free1(sizeof(*mf), mf);
	g_hash_table_destroy(mf->ssrc_hash);
}


// mf is locked
static void meta_destroy(metafile_t *mf) {
	// close all streams
	for (int i = 0; i < mf->streams->len; i++) {
		stream_t *stream = g_ptr_array_index(mf->streams, i);
		pthread_mutex_lock(&stream->lock);
		stream_close(stream);
		pthread_mutex_unlock(&stream->lock);
	}
}


// mf is locked
static void meta_stream_interface(metafile_t *mf, unsigned long snum, char *content) {
	dbg("stream %lu interface %s", snum, content);
	stream_open(mf, snum, content);
}


// mf is locked
static void meta_stream_details(metafile_t *mf, unsigned long snum, char *content) {
	dbg("stream %lu details %s", snum, content);
}


// mf is locked
static void meta_rtp_payload_type(metafile_t *mf, unsigned long mnum, unsigned int payload_num,
		char *payload_type)
{
	dbg("payload type in media %lu num %u is %s", mnum, payload_num, payload_type);

	if (payload_num >= 128) {
		ilog(LOG_ERR, "Payload type number %u is invalid", payload_num);
		return;
	}

	pthread_mutex_lock(&mf->payloads_lock);
	mf->payload_types[payload_num] = g_string_chunk_insert(mf->gsc, payload_type);
	pthread_mutex_unlock(&mf->payloads_lock);
}


// mf is locked
static void meta_section(metafile_t *mf, char *section, char *content, unsigned long len) {
	unsigned long lu;
	unsigned int u;

	if (!strcmp(section, "CALL-ID"))
		mf->call_id = g_string_chunk_insert(mf->gsc, content);
	else if (!strcmp(section, "PARENT"))
		mf->parent = g_string_chunk_insert(mf->gsc, content);
	else if (sscanf_match(section, "STREAM %lu interface", &lu) == 1)
		meta_stream_interface(mf, lu, content);
	else if (sscanf_match(section, "STREAM %lu details", &lu) == 1)
		meta_stream_details(mf, lu, content);
	else if (sscanf_match(section, "MEDIA %lu PAYLOAD TYPE %u", &lu, &u) == 2)
		meta_rtp_payload_type(mf, lu, u, content);
}


// returns mf locked
static metafile_t *metafile_get(char *name) {
	// get or create metafile metadata
	pthread_mutex_lock(&metafiles_lock);
	metafile_t *mf = g_hash_table_lookup(metafiles, name);
	if (mf)
		goto out;

	dbg("allocating metafile info for %s", name);
	mf = g_slice_alloc0(sizeof(*mf));
	mf->gsc = g_string_chunk_new(0);
	mf->name = g_string_chunk_insert(mf->gsc, name);
	pthread_mutex_init(&mf->lock, NULL);
	pthread_mutex_init(&mf->payloads_lock, NULL);
	mf->streams = g_ptr_array_new();
	mf->ssrc_hash = g_hash_table_new_full(g_direct_hash, g_direct_equal, NULL, ssrc_free);

	g_hash_table_insert(metafiles, mf->name, mf);

out:
	// switch locks
	pthread_mutex_lock(&mf->lock);
	pthread_mutex_unlock(&metafiles_lock);

	return mf;
}


void metafile_change(char *name) {
	metafile_t *mf = metafile_get(name);

	char fnbuf[PATH_MAX];
	snprintf(fnbuf, sizeof(fnbuf), "%s/%s", spool_dir, name);

	// open file and seek to last known position
	int fd = open(fnbuf, O_RDONLY);
	if (fd == -1) {
		ilog(LOG_ERR, "Failed to open %s: %s\n", fnbuf, strerror(errno));
		goto out;
	}
	lseek(fd, mf->pos, SEEK_SET);

	// read the entire file
	GString *s = g_string_new(NULL);
	char buf[1024];
	while (1) {
		int ret = read(fd, buf, sizeof(buf));
		if (ret == 0)
			break;
		if (ret == -1)
			die_errno("read on metadata file failed");
		g_string_append_len(s, buf, ret);
	}

	// save read position and close file
	mf->pos = lseek(fd, 0, SEEK_CUR);
	close(fd);

	// process contents of metadata file
	// XXX use "str" type?
	char *head = s->str;
	char *endp = s->str + s->len;
	while (head < endp) {
		// section header
		char *nl = memchr(head, '\n', endp - head);
		if (!nl || nl == head) {
			ilog(LOG_WARN, "Missing section header in %s", name);
			break;
		}
		if (memchr(head, '\0', nl - head)) {
			ilog(LOG_WARN, "NUL character in section header in %s", name);
			break;
		}
		*(nl++) = '\0';
		char *section = head;
		dbg("section %s", section);
		head = nl;

		// content length
		nl = memchr(head, ':', endp - head);
		if (!nl || nl == head) {
			ilog(LOG_WARN, "Content length for section %s missing in %s", section, name);
			break;
		}
		*(nl++) = '\0';
		if (*(nl++) != '\n') {
			ilog(LOG_WARN, "Unterminated content length for section %s in %s", section, name);
			break;
		}
		char *errp;
		unsigned long slen = strtoul(head, &errp, 10);
		if (*errp != '\0') {
			ilog(LOG_WARN, "Invalid content length for section %s in %s", section, name);
			break;
		}
		dbg("content length %lu", slen);
		head = nl;

		// content
		if (endp - head < slen) {
			ilog(LOG_WARN, "Content truncated in section %s in %s", section, name);
			break;
		}
		char *content = head;
		if (memchr(content, '\0', slen)) {
			ilog(LOG_WARN, "NUL character in content in section %s in %s", section, name);
			break;
		}

		// double newline separator
		head += slen;
		if (*head != '\n' || *(head + 1) != '\n') {
			ilog(LOG_WARN, "Separator missing after section %s in %s", section, name);
			break;
		}
		*head = '\0';
		head += 2;

		meta_section(mf, section, content, slen);
	}

	g_string_free(s, TRUE);

out:
	pthread_mutex_unlock(&mf->lock);
}


void metafile_delete(char *name) {
	// get metafile metadata
	pthread_mutex_lock(&metafiles_lock);
	metafile_t *mf = g_hash_table_lookup(metafiles, name);
	if (!mf) {
		// nothing to do
		pthread_mutex_unlock(&metafiles_lock);
		return;
	}
	// switch locks and remove entry
	pthread_mutex_lock(&mf->lock);
	g_hash_table_remove(metafiles, name);
	pthread_mutex_unlock(&metafiles_lock);

	meta_destroy(mf);

	// add to garbage
	garbage_add(mf, meta_free);
	pthread_mutex_unlock(&mf->lock);
}


void metafile_setup(void) {
	metafiles = g_hash_table_new(g_str_hash, g_str_equal);
	//pcre_build(&stream_interface_re, "^STREAM (\\d+) interface$");
	//pcre_build(&stream_interface_re, "^STREAM (\\d+) details$");
}


void metafile_cleanup(void) {
	GList *mflist = g_hash_table_get_values(metafiles);
	for (GList *l = mflist; l; l = l->next) {
		metafile_t *mf = l->data;
		meta_destroy(mf);
		meta_free(mf);
		
	}
	g_list_free(mflist);
	g_hash_table_destroy(metafiles);
}