/*!
 * \file   mg_db_gd_pg.c
 * \brief  A capsule around postgresql database access
 *
 * \version $Revision: 1.2 $
 * \date    $Date: 2005-04-13 17:42:54 +0100 (Thu, 13 Apr 2005) $
 * \author  Wolfgang Rohdewald
 * \author  Responsible author: $Author: wolfgang61 $
 */

#include <string>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#include <sys/time.h>
#include <time.h>
#include <assert.h>

#include "mg_setup.h"
#include "mg_item_gd.h"
#include "mg_db_gd_pg.h"
#include <libpq-fe.h>

#include <pg_config.h>

using namespace std;

mgQueryPG::mgQueryPG(void* db,string sql,mgQueryNoise noise)
: mgQueryImp(db,sql,noise) {
	m_db = (PGconn*)m_db_handle;
	m_cursor = 0;
	m_table = PQexec(m_db,m_optsql);
	switch ((m_rc=PQresultStatus(m_table))) {
		case PGRES_COMMAND_OK:
			m_rows = atol(PQcmdTuples(m_table));
			break;;
		case PGRES_TUPLES_OK:
			m_rows = PQntuples(m_table);
			m_columns = PQnfields(m_table);
			break;
		default:
			m_errormessage = PQresultErrorMessage (m_table);
			break;
	}
	HandleErrors();
}

mgQueryPG::~mgQueryPG() {
	PQclear(m_table);
}

char **
mgQueryPG::Next() {
	if (m_cursor>=Rows())
		return 0;
	assert(Columns()<100);
	memset(m_rowpointers,0,sizeof(m_rowpointers));
	for (int idx=0;idx<Columns();idx++)
		if (!PQgetisnull(m_table,m_cursor,idx))
			m_rowpointers[idx] = PQgetvalue(m_table,m_cursor,idx);
	m_cursor++;
	return m_rowpointers;
}

mgSQLStringPG::~mgSQLStringPG() {
	if (m_unquoted)
		free(m_unquoted);
}

mgSQLStringPG::mgSQLStringPG(const char*s) {
	m_unquoted = 0;
	m_original = s;
}

char*
mgSQLStringPG::unquoted() const
{
	if (!m_unquoted) {
		int buflen=2*strlen(m_original)+5;
		m_unquoted = (char *) malloc( buflen);
		PQescapeString(m_unquoted,m_original,strlen(m_original));
	}
	return m_unquoted;
}

const char*
mgDbGd::Options() const
{
	return "hspuw";
}

const char*
mgDbGd::HelpText() const
{
	return
		"  -h HHHH,  --host=HHHH     specify database host (default is localhost)\n"
		"  -s SSSS   --socket=PATH   specify database socket\n"
		"  -p PPPP,  --port=PPPP     specify port of database server\n"
		"  -u UUUU,  --user=UUUU     specify database user (default is current login name)\n"
		"  -w WWWW,  --password=WWWW specify database password (default is empty)\n"
		"\n"
		" if the database runs on the same computer you should only need -u and -w if\n"
		" at all, see README.postgresql\n";
}

mgDb* GenerateDB(bool SeparateThread) {
	// \todo should return different backends according to the_setup.Variant
	return new mgDbGd(SeparateThread);
}

static bool needGenre2;
static bool needGenre2_set=false;

mgDbGd::mgDbGd(bool SeparateThread) {
	m_db = 0;
	if (m_separate_thread)
		if (!Threadsafe())
			mgError("Your database library is not thread safe");
}

mgDbGd::~mgDbGd() {
	PQfinish (m_db);
	m_db = 0;
}

bool
mgDbGd::Threadsafe() {
	return ENABLE_THREAD_SAFETY;
}

static const char *db_cmds[] = {
	"DROP TABLE IF EXISTS album",
	"CREATE TABLE album ( "
	"artist varchar(255) default NULL, "
	"title varchar(255) default NULL, "
	"cddbid varchar(20) default '', "
	"coverimg varchar(255) default NULL, "
	"covertxt text, "
	"modified date default NULL, "
	"genre varchar(10) default NULL, "
	"PRIMARY KEY  (cddbid))",
	"CREATE INDEX alb_artist ON album (artist)",
	"CREATE INDEX alb_title ON album (title)",
	"DROP TABLE IF EXISTS genre",
	"CREATE TABLE genre ("
	"id varchar(10) NOT NULL default '', "
	"id3genre smallint default NULL, "
	"genre varchar(255) default NULL, "
	"freq int default NULL, "
	"PRIMARY KEY (id))",
	"DROP TABLE IF EXISTS language",
	"CREATE TABLE language ("
	"id varchar(4) NOT NULL default '', "
	"language varchar(40) default NULL, "
	"freq int default NULL, "
	"PRIMARY KEY  (id))",
	"DROP TABLE IF EXISTS musictype",
	"CREATE TABLE musictype ("
	"musictype varchar(40) default NULL, "
	"id serial, "
	"PRIMARY KEY  (id)) ",
	"DROP TABLE IF EXISTS playlist",
	"CREATE TABLE playlist ( "
	"title varchar(255) default NULL, "
	"author varchar(255) default NULL, "
	"note varchar(255) default NULL, "
	"created timestamp default NULL, "
	"id serial, "
	"PRIMARY KEY  (id))",
	"DROP TABLE IF EXISTS playlistitem",
	"CREATE TABLE playlistitem ( "
	"playlist int NOT NULL,"
	"trackid int NOT NULL) WITH OIDS",
	"DROP TABLE IF EXISTS source",
	"CREATE TABLE source ( "
	"source varchar(40) default NULL, "
	"id serial, "
	"PRIMARY KEY  (id)) ",
	"DROP TABLE IF EXISTS tracks",
	"CREATE TABLE tracks ( "
	"artist varchar(255) default NULL, "
	"title varchar(255) default NULL, "
	"genre1 varchar(10) default NULL, "
	"genre2 varchar(10) default NULL, "
	"year smallint default NULL, "
	"lang varchar(4) default NULL, "
	"type smallint default NULL, "
	"rating smallint default NULL, "
	"length smallint default NULL, "
	"source smallint default NULL, "
	"sourceid varchar(20) default NULL, "
	"tracknb smallint default NULL, "
	"mp3file varchar(255) default NULL, "
	"quality smallint default NULL, "
	"voladjust smallint default '0', "
	"lengthfrm int default '0', "
	"startfrm int default '0', "
	"bpm smallint default '0', "
	"lyrics text, "
	"bitrate varchar(10) default NULL, "
	"created date default NULL, "
	"modified date default NULL, "
	"backup smallint default NULL, "
	"samplerate int default NULL, "
	"channels   smallint default NULL,  "
	"id serial, "
	"folder1 varchar(255), "
	"folder2 varchar(255), "
	"folder3 varchar(255), "
	"folder4 varchar(255), "
	"PRIMARY KEY  (id))",
	"CREATE INDEX tracks_title ON tracks (title)",
	"CREATE INDEX tracks_sourceid ON tracks (sourceid)",
	"CREATE INDEX tracks_mp3file ON tracks (mp3file)",
	"CREATE INDEX tracks_genre1 ON tracks (genre1)",
	"CREATE INDEX tracks_genre2 ON tracks (genre2)",
	"CREATE INDEX tracks_year ON tracks (year)",
	"CREATE INDEX tracks_lang ON tracks (lang)",
	"CREATE INDEX tracks_artist ON tracks (artist)",
	"CREATE INDEX tracks_rating ON tracks (rating)",
	"CREATE INDEX tracks_folder1 ON tracks (folder1)",
	"CREATE INDEX tracks_folder2 ON tracks (folder2)",
	"CREATE INDEX tracks_folder3 ON tracks (folder3)",
	"CREATE INDEX tracks_folder4 ON tracks (folder4)",
};

void
mgDbGd::StartTransaction() {
	Execute("BEGIN TRANSACTION");
}

void
mgDbGd::Commit() {
	Execute("COMMIT");
}

bool
mgDbGd::SetCharset() {
	const char *cmd;
	if (the_setup.utf8)
		cmd="SET NAMES 'UTF8'";
	else
		cmd="SET NAMES 'LATIN1'";
	mgQuery q0(m_db,cmd);
	if (!q0.ErrorMessage().empty())
		return false;
	return true;
}

bool
mgDbGd::Creatable() {
	return false;
}

bool
mgDbGd::Create() {
	return false;
}

bool
mgDbGd::Clear() {
	// create database and tables
	int len = sizeof( db_cmds ) / sizeof( char* );
	for( int i=0; i < len; i ++ ) {
		mgQuery q(m_db,db_cmds[i],mgQueryWarnOnly);
		if (!q.ErrorMessage().empty())
			return false;
	}
	return true;
}

bool
mgDbGd::ServerConnect () {
	return true;
}

bool
mgDbGd::ConnectDatabase () {
	char conninfo[500];
	char port[20];
	char host[200];
	char *user;
	if (the_setup.DbPort>0)
		sprintf(port," port = %d ",the_setup.DbPort);
	else
		port[0]=0;
	if (notempty(the_setup.DbHost))
		snprintf(host,199," host = %s ",the_setup.DbHost);
	else if (notempty(the_setup.DbSocket))
		snprintf(host,199," host = %s ",the_setup.DbSocket);
	else
		host[0]=0;
	if (the_setup.DbUser==0)
		user=getenv("LOGNAME");
	else
		user=the_setup.DbUser;
	snprintf(conninfo,499,"%s %s dbname = %s user = %s ",
		host,port,the_setup.DbName,user);
	m_db = PQconnectdb(conninfo);
	if (PQstatus(m_db) != CONNECTION_OK) {
		mgWarning("Failed to connect to postgres server using %s:%s",conninfo,PQerrorMessage(m_db));
		return false;
	}
	return SetCharset();
}

bool
mgDbGd::NeedGenre2() {
	if (!needGenre2_set && Connect()) {
		needGenre2_set=true;
		needGenre2=exec_count("SELECT COUNT(DISTINCT genre2) FROM tracks")>1;
	}
	return needGenre2;
}

bool
mgDbGd::FieldExists(string table, string field) {
	char *b;
	msprintf(&b,"SELECT COUNT(*) FROM information_schema.columns WHERE table_name='%s' AND column_name='%s'",
		table.c_str(),field.c_str());
	bool result = exec_count(b)==1;
	free(b);
	return result;
}

const char*
mgDbGd::DecadeExpr() {
	return "substring(cast(10 * floor(tracks.year/10) as char(4)),3)";
}