/*-------------------------------------------------------------------------
 *
 * ogr_fdw_info.c
 *		Commandline utility to read an OGR layer and output a
 *		SQL "create table" statement.
 *
 * Copyright (c) 2014-2015, Paul Ramsey <pramsey@cleverelephant.ca>
 *
 *-------------------------------------------------------------------------
 */

/* getopt */
#include <unistd.h>

/*
 * OGR library API
 */
#include "ogr_fdw_gdal.h"
#include "ogr_fdw_common.h"

static void usage();
static OGRErr ogrListLayers(const char* source);
static OGRErr ogrGenerateSQL(const char* source, const char* layer);

#define STR_MAX_LEN 256


/* Define this no-op here, so that code */
/* in the ogr_fdw_common module works */
const char* quote_identifier(const char* ident);

const char*
quote_identifier(const char* ident)
{
	return ident;
}


static void
formats()
{
	int i;

	GDALAllRegister();

	printf("Supported Formats:\n");
	for (i = 0; i < GDALGetDriverCount(); i++)
	{
		GDALDriverH ogr_dr = GDALGetDriver(i);
		int vector = FALSE;
		int createable = TRUE;
		const char* tmpl;

#if GDAL_VERSION_MAJOR >= 2
		char** papszMD = GDALGetMetadata(ogr_dr, NULL);
		vector = CSLFetchBoolean(papszMD, GDAL_DCAP_VECTOR, FALSE);
		createable = CSLFetchBoolean(papszMD, GDAL_DCAP_CREATE, FALSE);
#else
		createable = GDALDatasetTestCapability(ogr_dr, ODrCCreateDataSource);
#endif
		/* Skip raster data sources */
		if (! vector)
		{
			continue;
		}

		/* Report sources w/ create capability as r/w */
		if (createable)
		{
			tmpl = "  -> \"%s\" (read/write)\n";
		}
		else
		{
			tmpl = "  -> \"%s\" (readonly)\n";
		}

		printf(tmpl, GDALGetDriverShortName(ogr_dr));
	}

	exit(0);
}

static void
usage()
{
	printf(
	    "usage: ogr_fdw_info -s <ogr datasource> -l <ogr layer>\n"
	    "	   ogr_fdw_info -s <ogr datasource>\n"
	    "	   ogr_fdw_info -f\n"
	    "\n");
	exit(0);
}

int
main(int argc, char** argv)
{
	int ch;
	char* source = NULL, *layer = NULL;
	OGRErr err = OGRERR_NONE;

	/* If no options are specified, display usage */
	if (argc == 1)
	{
		usage();
	}

	while ((ch = getopt(argc, argv, "h?s:l:f")) != -1)
	{
		switch (ch)
		{
		case 's':
			source = optarg;
			break;
		case 'l':
			layer = optarg;
			break;
		case 'f':
			formats();
			break;
		case '?':
		case 'h':
		default:
			usage();
			break;
		}
	}

	if (source && ! layer)
	{
		err = ogrListLayers(source);
	}
	else if (source && layer)
	{
		err = ogrGenerateSQL(source, layer);
	}
	else if (! source && ! layer)
	{
		usage();
	}

	if (err != OGRERR_NONE)
	{
		// printf("OGR Error: %s\n\n", CPLGetLastErrorMsg());
	}

	OGRCleanupAll();
	exit(0);
}

static OGRErr
ogrListLayers(const char* source)
{
	GDALDatasetH ogr_ds = NULL;
	int i;

	GDALAllRegister();

#if GDAL_VERSION_MAJOR < 2
	ogr_ds = OGROpen(source, FALSE, NULL);
#else
	ogr_ds = GDALOpenEx(source,
	                    GDAL_OF_VECTOR | GDAL_OF_READONLY,
	                    NULL, NULL, NULL);
#endif

	if (! ogr_ds)
	{
		CPLError(CE_Failure, CPLE_AppDefined, "Could not connect to source '%s'", source);
		return OGRERR_FAILURE;
	}

	printf("Layers:\n");
	for (i = 0; i < GDALDatasetGetLayerCount(ogr_ds); i++)
	{
		OGRLayerH ogr_lyr = GDALDatasetGetLayer(ogr_ds, i);
		if (! ogr_lyr)
		{
			return OGRERR_FAILURE;
		}
		printf("  %s\n", OGR_L_GetName(ogr_lyr));
	}
	printf("\n");

	GDALClose(ogr_ds);

	return OGRERR_NONE;
}

static OGRErr
ogrGenerateSQL(const char* source, const char* layer)
{
	OGRErr err;
	GDALDatasetH ogr_ds = NULL;
	GDALDriverH ogr_dr = NULL;
	OGRLayerH ogr_lyr = NULL;
	char server_name[STR_MAX_LEN];
	stringbuffer_t buf;

	GDALAllRegister();

#if GDAL_VERSION_MAJOR < 2
	ogr_ds = OGROpen(source, FALSE, &ogr_dr);
#else
	ogr_ds = GDALOpenEx(source,
	                    GDAL_OF_VECTOR | GDAL_OF_READONLY,
	                    NULL, NULL, NULL);
#endif

	if (! ogr_ds)
	{
		CPLError(CE_Failure, CPLE_AppDefined, "Could not connect to source '%s'", source);
		return OGRERR_FAILURE;
	}

	if (! ogr_dr)
	{
		ogr_dr = GDALGetDatasetDriver(ogr_ds);
	}

	/* There should be a nicer way to do this */
	strcpy(server_name, "myserver");

	ogr_lyr = GDALDatasetGetLayerByName(ogr_ds, layer);
	if (! ogr_lyr)
	{
		CPLError(CE_Failure, CPLE_AppDefined, "Could not find layer '%s' in source '%s'", layer, source);
		return OGRERR_FAILURE;
	}

	/* Output SERVER definition */
	printf("\nCREATE SERVER %s\n"
	       "  FOREIGN DATA WRAPPER ogr_fdw\n"
	       "  OPTIONS (\n"
	       "	datasource '%s',\n"
	       "	format '%s' );\n",
	       server_name, source, GDALGetDriverShortName(ogr_dr));

	stringbuffer_init(&buf);
	err = ogrLayerToSQL(ogr_lyr,
	                    server_name,
	                    TRUE, /* launder table names */
	                    TRUE, /* launder column names */
	                    TRUE, /* use postgis geometry */
	                    &buf);

	GDALClose(ogr_ds);

	if (err != OGRERR_NONE)
	{
		return err;
	}

	printf("\n%s\n", stringbuffer_getstring(&buf));
	stringbuffer_release(&buf);
	return OGRERR_NONE;
}