#include <fstream.hfa>
#include <parseargs.hfa>
#include <stdlib.hfa>
#include <string.h>
#include "parseconfig.hfa"


// *********************************** exceptions ***********************************


static vtable(Parse_Failure) Parse_Failure_vt;

void ?{}( Parse_Failure & this ) with ( this ) {
	virtual_table = &Parse_Failure_vt;
}

static vtable(Validation_Failure) Validation_Failure_vt;

void ?{}( Validation_Failure & this ) with ( this ) {
	virtual_table = &Validation_Failure_vt;
}


// *********************************** main code ***********************************


struct KVPairs {
	size_t size, max_size;
	* [ char *, char * ] data;
};

void ?{}( KVPairs & kvp ) with ( kvp ) {				// default constructor
	size = 0; max_size = 0; data = 0p;
}

void ?{}( KVPairs & kvp, size_t size ) { 				// initialization
	kvp.[ size, max_size ] = [ 0, size ];
	kvp.data = alloc( size );
}

void ^?{}( KVPairs & kvp ) with ( kvp ) {				// destructor
	for ( i; size ) free( data[i] );
	free( data );
	size = 0; max_size = 0; data = 0p;
}

void add_kv_pair( KVPairs & kv_pairs, char * k, char * v ) with ( kv_pairs ) {
	if ( max_size == 0 ) {
		max_size = 1;
		data = alloc( max_size );
	} else if ( size == max_size ) {
		max_size *= 2;
		data = alloc( max_size, data`realloc );
	}

	data[size].0 = alloc( strlen( k ) );
	data[size].1 = alloc( strlen( v ) );
	strcpy( data[size].0, k );
	strcpy( data[size].1, v );
	++size;
}


bool comments( ifstream & in, char name[] ) {
	while () {
		in | name;
	  if ( eof( in ) ) return true;
	  if ( name[0] != '#' ) return false;
		in | nl;									// ignore remainder of line
	} // while
} // comments

// Parse configuration from a file formatted in shell style
KVPairs * parse_tabular_config_format( const char * config_file, size_t num_entries ) {
	* KVPairs kv_pairs = new( num_entries );

	ifstream in;
	try {
		open( in, config_file );					// open the configuration file for input

		char key[64];
		char value[256];

		while () {									// parameter names can appear in any order
		  	// Must add check to see if already read in a key-value pair,
			// once we switch to using hash table as intermediate storage
		  if ( comments( in, key ) ) break;			// eof ?
			in | value;

			add_kv_pair( *kv_pairs, key, value );

		  if ( eof( in ) ) break;
			in | nl;								// ignore remainder of line
		} // for
	} catch( Open_Failure * ex; ex->istream == &in ) {
		delete( kv_pairs );
		serr | "Error: could not open input file '" | config_file | "'";
		throw *ex;
	} // try
	close( in );

	return kv_pairs;
}

// Parse configuration values from intermediate format
void parse_config( const char * config_file, config_entry entries[], size_t num_entries, config_format format ) {
	KVPairs * kv_pairs = 0p;
	choose ( format ) {
		case TABULAR_CONFIG:
			kv_pairs = parse_tabular_config_format( config_file, num_entries );
	}

	int entries_so_far = 0;
	for ( i; kv_pairs->size ) {
	  if ( entries_so_far == num_entries ) break;

		char * src_key, * src_value;
		[ src_key, src_value ] = kv_pairs->data[i];

		for ( j; num_entries ) {
		  if ( strcmp( src_key, entries[j].key ) != 0 ) continue;
		  	if ( !entries[j].parse( src_value, entries[j].variable ) ) {
				delete( kv_pairs );
				serr | "Error: value '" | src_value | "' for key '" | src_key | "' could not be parsed";
				throw (Parse_Failure){};
			}

			// Validate the parsed data, if necessary
			if ( entries[j].validate != (bool (*)(void *))0p
					&& !entries[j].validate( entries[j].variable ) ) {
				delete( kv_pairs );
				serr | "Error: config value at key '" | entries[j].key | "' did not pass validation";
				throw (Validation_Failure){};
			}

			++entries_so_far;

			break;
		}
	}

	delete( kv_pairs );
} // processConfigFile


// *********************************** validation ***********************************


forall(T | Relational( T ))
bool is_nonnegative( T & value ) {
	T zero_val = 0;
	return value >= zero_val;
}

forall(T | Relational( T ))
bool is_positive( T & value ) {
	T zero_val = 0;
	return value > zero_val;
}

forall(T | Relational( T ))
bool is_nonpositive( T & value ) {
	T zero_val = 0;
	return value <= zero_val;
}

forall(T | Relational( T ))
bool is_negative( T & value ) {
	T zero_val = 0;
	return value < zero_val;
}


// Local Variables: //
// tab-width: 4 //
// compile-command: "cfa parseconfig.cfa" //
// End: //