//
//  Sample code to demonstrate how to execute Gravity code from C
//  Created by Marco Bambini on 06/03/2017.
//

#include <stdio.h>
#include "gravity_compiler.h"
#include "gravity_macros.h"
#include "gravity_core.h"
#include "gravity_vm.h"

// gravity func source code
static const char *source = "func add (a, b) {return a + b;}; \
                             func mul (a, b) {return a * b;};";

// error callback
static void report_error (error_type_t error_type, const char *message,
						  error_desc_t error_desc, void *xdata) {
	#pragma unused(xdata)
	const char *type = "N/A";
	switch (error_type) {
		case GRAVITY_ERROR_NONE: type = "NONE"; break;
		case GRAVITY_ERROR_SYNTAX: type = "SYNTAX"; break;
		case GRAVITY_ERROR_SEMANTIC: type = "SEMANTIC"; break;
		case GRAVITY_ERROR_RUNTIME: type = "RUNTIME"; break;
		case GRAVITY_WARNING: type = "WARNING"; break;
		case GRAVITY_ERROR_IO: type = "I/O"; break;
	}
	
	if (error_type == GRAVITY_ERROR_RUNTIME) printf("RUNTIME ERROR: ");
	else printf("%s ERROR on %d (%d,%d): ", type, error_desc.fileid, error_desc.lineno, error_desc.colno);
	printf("%s\n", message);
}


int main(int argc, const char * argv[]) {
	
	// setup a minimal delegate
	gravity_delegate_t delegate = {
		.error_callback = report_error
	};
	
	// compile source into a closure
	gravity_compiler_t *compiler = gravity_compiler_create(&delegate);
	gravity_closure_t *closure = gravity_compiler_run(compiler, source, strlen(source), 0, true);
	if (!closure) return -1;
	
	// setup a new VM and a new fiber
	gravity_vm *vm = gravity_vm_new(&delegate);	
	
	// transfer memory from compiler to VM and then free compiler
	gravity_compiler_transfer(compiler, vm);
	gravity_compiler_free(compiler);
	
	// load closure into VM context
	gravity_vm_loadclosure(vm, closure);
	
	// create parameters (that must be boxed) for the closure
	gravity_value_t n1 = VALUE_FROM_INT(30);
	gravity_value_t n2 = VALUE_FROM_INT(50);
	gravity_value_t params[2] = {n1, n2};
	
	// lookup add closure
	gravity_value_t add = gravity_vm_getvalue(vm, "add", strlen("add"));
	if (!VALUE_ISA_CLOSURE(add)) return -2;
	
	// execute add closure and print result
	if (gravity_vm_runclosure(vm, VALUE_AS_CLOSURE(add), add, params, 2)) {
		gravity_value_t result = gravity_vm_result(vm);
		printf("add result ");
		gravity_value_dump(result, NULL, 0);
	}
	
	// lookup mul closure
	gravity_value_t mul = gravity_vm_getvalue(vm, "mul", strlen("mul"));
	if (!VALUE_ISA_CLOSURE(mul)) return -3;
	
	// execute mul closure and print result
	if (gravity_vm_runclosure(vm, VALUE_AS_CLOSURE(mul), mul, params, 2)) {
		gravity_value_t result = gravity_vm_result(vm);
		printf("mul result ");
		gravity_value_dump(result, NULL, 0);
	}
	
	// free vm and core classes
	gravity_vm_free(vm);
	gravity_core_free();
	
    return 0;
}