
#include <isl/ctx.h>
#include <isl/options.h>

#include <functional>
#include <memory>
#include <stdexcept>
#include <string>

/* ISL_USE_EXCEPTIONS should be defined to 1 if exceptions are available.
 * gcc and clang define __cpp_exceptions; MSVC and xlC define _CPPUNWIND.
 * If exceptions are not available, any error condition will result
 * in an abort.
 */
#ifndef ISL_USE_EXCEPTIONS
#if defined(__cpp_exceptions) || defined(_CPPUNWIND)
#define ISL_USE_EXCEPTIONS	1
#else
#define ISL_USE_EXCEPTIONS	0
#endif
#endif

namespace isl {

class ctx {
	isl_ctx *ptr;
public:
	/* implicit */ ctx(isl_ctx *ctx) : ptr(ctx) {}
	isl_ctx *release() {
		auto tmp = ptr;
		ptr = nullptr;
		return tmp;
	}
	isl_ctx *get() {
		return ptr;
	}
};

/* Macros hiding try/catch.
 * If exceptions are not available, then no exceptions will be thrown and
 * there is nothing to catch.
 */
#if ISL_USE_EXCEPTIONS
#define ISL_CPP_TRY		try
#define ISL_CPP_CATCH_ALL	catch (...)
#else
#define ISL_CPP_TRY		if (1)
#define ISL_CPP_CATCH_ALL	if (0)
#endif

#if ISL_USE_EXCEPTIONS

/* Class capturing isl errors.
 *
 * The what() return value is stored in a reference counted string
 * to ensure that the copy constructor and the assignment operator
 * do not throw any exceptions.
 */
class exception : public std::exception {
	std::shared_ptr<std::string> what_str;

protected:
	inline exception(const char *what_arg, const char *msg,
		const char *file, int line);
public:
	exception() {}
	exception(const char *what_arg) {
		what_str = std::make_shared<std::string>(what_arg);
	}
	static inline exception create(enum isl_error error, const char *msg,
		const char *file, int line);
	static inline exception create_from_last_error(ctx ctx);
	virtual const char *what() const noexcept {
		return what_str->c_str();
	}

	/* Default behavior on error conditions that occur inside isl calls
	 * performed from inside the bindings.
	 * In the case exceptions are available, isl should continue
	 * without printing a warning since the warning message
	 * will be included in the exception thrown from inside the bindings.
	 */
	static constexpr auto on_error = ISL_ON_ERROR_CONTINUE;
	/* Wrapper for throwing an exception on NULL input.
	 */
	static void throw_NULL_input(const char *file, int line) {
		throw create(isl_error_invalid, "NULL input", file, line);
	}
	/* Wrapper for throwing an exception corresponding to the last
	 * error on "ctx".
	 */
	static void throw_last_error(ctx ctx) {
		throw create_from_last_error(ctx);
	}
};

/* Create an exception of a type described by "what_arg", with
 * error message "msg" in line "line" of file "file".
 *
 * Create a string holding the what() return value that
 * corresponds to what isl would have printed.
 * If no error message or no error file was set, then use "what_arg" instead.
 */
exception::exception(const char *what_arg, const char *msg, const char *file,
	int line)
{
	if (!msg || !file)
		what_str = std::make_shared<std::string>(what_arg);
	else
		what_str = std::make_shared<std::string>(std::string(file) +
				    ":" + std::to_string(line) + ": " + msg);
}

class exception_abort : public exception {
	friend exception;
	exception_abort(const char *msg, const char *file, int line) :
		exception("execution aborted", msg, file, line) {}
};

class exception_alloc : public exception {
	friend exception;
	exception_alloc(const char *msg, const char *file, int line) :
		exception("memory allocation failure", msg, file, line) {}
};

class exception_unknown : public exception {
	friend exception;
	exception_unknown(const char *msg, const char *file, int line) :
		exception("unknown failure", msg, file, line) {}
};

class exception_internal : public exception {
	friend exception;
	exception_internal(const char *msg, const char *file, int line) :
		exception("internal error", msg, file, line) {}
};

class exception_invalid : public exception {
	friend exception;
	exception_invalid(const char *msg, const char *file, int line) :
		exception("invalid argument", msg, file, line) {}
};

class exception_quota : public exception {
	friend exception;
	exception_quota(const char *msg, const char *file, int line) :
		exception("quota exceeded", msg, file, line) {}
};

class exception_unsupported : public exception {
	friend exception;
	exception_unsupported(const char *msg, const char *file, int line) :
		exception("unsupported operation", msg, file, line) {}
};

/* Create an exception of the class that corresponds to "error", with
 * error message "msg" in line "line" of file "file".
 *
 * isl_error_none is treated as an invalid error type.
 */
exception exception::create(enum isl_error error, const char *msg,
	const char *file, int line)
{
	switch (error) {
	case isl_error_none:
		break;
	case isl_error_abort: return exception_abort(msg, file, line);
	case isl_error_alloc: return exception_alloc(msg, file, line);
	case isl_error_unknown: return exception_unknown(msg, file, line);
	case isl_error_internal: return exception_internal(msg, file, line);
	case isl_error_invalid: return exception_invalid(msg, file, line);
	case isl_error_quota: return exception_quota(msg, file, line);
	case isl_error_unsupported:
				return exception_unsupported(msg, file, line);
	}

	throw exception_invalid("invalid error type", file, line);
}

/* Create an exception from the last error that occurred on "ctx" and
 * reset the error.
 *
 * If "ctx" is NULL or if it is not in an error state at the start,
 * then an invalid argument exception is thrown.
 */
exception exception::create_from_last_error(ctx ctx)
{
	enum isl_error error;
	const char *msg, *file;
	int line;

	error = isl_ctx_last_error(ctx.get());
	msg = isl_ctx_last_error_msg(ctx.get());
	file = isl_ctx_last_error_file(ctx.get());
	line = isl_ctx_last_error_line(ctx.get());
	isl_ctx_reset_error(ctx.get());

	return create(error, msg, file, line);
}

#else

#include <stdio.h>
#include <stdlib.h>

class exception {
public:
	/* Default behavior on error conditions that occur inside isl calls
	 * performed from inside the bindings.
	 * In the case exceptions are not available, isl should abort.
	 */
	static constexpr auto on_error = ISL_ON_ERROR_ABORT;
	/* Wrapper for throwing an exception on NULL input.
	 * In the case exceptions are not available, print an error and abort.
	 */
	static void throw_NULL_input(const char *file, int line) {
		fprintf(stderr, "%s:%d: NULL input\n", file, line);
		abort();
	}
	/* Wrapper for throwing an exception corresponding to the last
	 * error on "ctx".
	 * isl should already abort when an error condition occurs,
	 * so this function should never be called.
	 */
	static void throw_last_error(ctx ctx) {
		abort();
	}
};

#endif

/* Helper class for setting the on_error and resetting the option
 * to the original value when leaving the scope.
 */
class options_scoped_set_on_error {
	isl_ctx *ctx;
	int saved_on_error;
public:
	options_scoped_set_on_error(class ctx ctx, int on_error) {
		this->ctx = ctx.get();
		saved_on_error = isl_options_get_on_error(this->ctx);
		isl_options_set_on_error(this->ctx, on_error);
	}
	~options_scoped_set_on_error() {
		isl_options_set_on_error(ctx, saved_on_error);
	}
};

} // namespace isl