#pragma once

#include <errno.h>

typedef enum Error_Code {
	ERR_NONE      = 0,
	ERR_SYSCALL   = 1,
	ERR_INVALID   = 2,
	ERR_NOT_FOUND = 3,
} Error_Code;

struct Syscall_Error_Detail {
	int err_no;
};

struct Invalid_Error_Detail {
	int         config_line;   /* source line number, or 0 if not applicable */
	const char *message;       /* static string describing what was wrong     */
};

struct App_Error {
	Error_Code  code;
	const char *file;
	int         line;
	union {
		struct Syscall_Error_Detail syscall;
		struct Invalid_Error_Detail invalid;
	} detail;
};

void app_error_print(struct App_Error *e);

#define APP_OK \
	((struct App_Error){ .code = ERR_NONE })

#define APP_IS_OK(e) \
	((e).code == ERR_NONE)

#define APP_SYSCALL_ERROR() \
	((struct App_Error){ \
		.code   = ERR_SYSCALL, \
		.file   = __FILE__, \
		.line   = __LINE__, \
		.detail = { .syscall = { .err_no = errno } }, \
	})

#define APP_INVALID_ERROR() \
	((struct App_Error){ \
		.code = ERR_INVALID, \
		.file = __FILE__, \
		.line = __LINE__, \
	})

#define APP_INVALID_ERROR_MSG(cfg_line, msg) \
	((struct App_Error){ \
		.code   = ERR_INVALID, \
		.file   = __FILE__, \
		.line   = __LINE__, \
		.detail = { .invalid = { .config_line = (cfg_line), .message = (msg) } }, \
	})

#define APP_NOT_FOUND_ERROR() \
	((struct App_Error){ \
		.code = ERR_NOT_FOUND, \
		.file = __FILE__, \
		.line = __LINE__, \
	})