#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <assert.h>
#include "db.h"
#include "firebase.h"
#include "user_data.h"


#define JS_PLUGIN_PATH "firebase-io/firebase-io.js"

FILE *js_write=NULL;


static void write_field(FILE *f,const char *key,const char *value){
	fprintf(f," %s %zu %s",key,strlen(value),value);
}

static void token_send(const char *token,const char *to_user,const char *room,const char *user,const char *msg){
	fprintf(stderr,"token_send(%s,%s,%s,%s,%s)\n",token,to_user,room,user,msg);
	fprintf(js_write,"message");
	write_field(js_write,"token",token);
	write_field(js_write,"room",room);
	write_field(js_write,"user",user);
	write_field(js_write,"to_user",to_user);
	write_field(js_write,"message",msg);
	fprintf(js_write,"\n");
	fflush(js_write);
}

static void script_output_listener(FILE *js_read){
	// Do not use js_write here, it's NULL
	char *line=NULL;
	size_t linecap=0;
	ssize_t linelen;
	while(true){
		linelen=getline(&line,&linecap,js_read);
		if(linelen<0){
			if(errno==EINTR)continue;
			break;
		}
		if(line[linelen-1]!='\n'){
			fprintf(stderr,"firebase thread: unexpected EOF from js script\n");
			return;
		}
		line[linelen-1]='\0';
		linelen--;

		char *spacep=strchr(line,' ');
		if(spacep==NULL)goto invalid_line;
		*spacep='\0';
		char *cmd=line;

		if(strcmp(cmd,"add_token")==0||strcmp(cmd,"delete_token")==0){
			char *username=spacep+1;
			spacep=strchr(username,' ');
			if(spacep==NULL)goto invalid_line;
			*spacep='\0';
			char *token=spacep+1;

			i64 userid=db_find_user(username);
			if(userid==-1){
				fprintf(stderr,"firebase thread: unknown username '%s'\n",username);
				continue;
			}

			if(strcmp(cmd,"add_token")==0){
				fprintf(stderr,"firebase thread: adding token '%s' to %" PRIi64 "\n",token,userid);
				db_add_token(userid,token);
			} else {
				fprintf(stderr,"firebase thread: deleting token '%s' from %" PRIi64 "\n",token,userid);
				db_delete_token(userid,token);
			}
		}

		continue;

	invalid_line:
		fprintf(stderr,"firebase thread: Invalid line from js script: <%s>\n",line);
	}

	if(linelen<0){
		if(feof(js_read)){
			fprintf(stderr,"firebase thread: feof(js_read)\n");
		} else {
			fprintf(stderr,"firebase thread: getline: errno = %d (%s)\n",errno,strerror(errno));
		}
	}
}


void firebase_init(void){
	int wrpipe[2],rdpipe[2];
	if(pipe(wrpipe)<0||pipe(rdpipe)<0){
		perror("pipe");
		exit(1);
	}

	pid_t pid=fork();  // The JS script
	if(pid<0){
		perror("fork");
		exit(1);
	}
	if(pid==0){
		close(wrpipe[1]);
		close(rdpipe[0]);
		dup2(wrpipe[0],0);
		dup2(rdpipe[1],1);
		execl(JS_PLUGIN_PATH,JS_PLUGIN_PATH,NULL);
		perror("execl");
		exit(1);
	}
	close(wrpipe[0]);
	close(rdpipe[1]);

	pid=fork();  // The script stdout listener
	if(pid<0){
		perror("fork");
		exit(1);
	}
	if(pid==0){
		close(wrpipe[1]);
		FILE *js_read=fdopen(rdpipe[0],"r");
		db_reinit();
		script_output_listener(js_read);
		fclose(js_read);
		exit(0);
	}

	js_write=fdopen(wrpipe[1],"w");
	printf("Started js firebase plugin\n");
}

void firebase_stop(void){
	if(js_write){
		// Script will stop itself on EOF on stdin
		fclose(js_write);
		js_write=NULL;
	}
}

void firebase_send_message(const char *room,i64 roomid,const char *user,const char *msg){
	// If not initialised, do nothing
	if(!js_write)return;

	if(roomid==-1)roomid=db_find_room(room);
	if(roomid==-1){
		debug("firebase_send_message: Cannot find roomid for room '%s'",room);
		return;
	}

	struct db_user_list members=db_list_members(roomid);
	for(i64 i=0;i<members.count;i++){
		if(userdata_is_active(members.list[i].id))continue;
		struct db_strings_list tokens=db_user_tokens(members.list[i].id);
		for(i64 j=0;j<tokens.count;j++){
			token_send(tokens.list[j],members.list[i].name,room,user,msg);
		}
		db_nullify_strings_list(tokens);
	}
	db_nullify_user_list(members);
}