/**
 * file: lslib.h
 * author: Tyler Murphy
 */

#ifndef SHARED_H
#define SHARED_H

#include <stdint.h>
#include <stdio.h>
#include <sys/stat.h>
#include <pwd.h>

/* create define flags to be used with color anscii codes */
#define ANSCII          "\x1b[" /* anscii start escape code */
#define NEXT            ";"     /* anscii seperator */

#define RESET           "0"
#define BOLD            "1"

#define NORMAL          "3"
#define BACKGROUND      "4"
#define HIGHLIGHT       "9"

#define BLACK           "0"
#define RED             "1"
#define GREEN           "2"
#define YELLOW          "3"
#define BLUE            "4"
#define MAGENTA         "5"
#define TURQUOISE       "6"
#define WHITE           "7"

#define COLOR           "m"     /* color anscii code */

/**
 * Define bool cause c89 dont have it
 */
typedef uint8_t bool;
#define true 1
#define false 0

/* mark argument unused */
#define UNUSED(x) (void)(x)

/*
 * Flags to return from parse_args fn pointers
 */
#define ARG_UNUSED  0 /* state that the next char* wasnt used */
#define ARG_USED    1 /* state that the next char* was used */
#define ARG_IGNORE  2 /* stop parsing arguments */
#define ARG_INVALID 3 /* print error message and die */

/*
 * Die is argument is null
 * @param arg argument to check
 */
void check_arg (char* arg);

/**
 * Print help message with lazysphere title then exit
 * @param help fn pointer to call to display fn specific help msg
 */
void global_help(void (*help)(void));

/**
 * Parse arguments and only check for --help message otherwise do nothing
 * @param argc argument count
 * @param argv argument data
 * @param help fn pointer to call and display fn specific help msg
 */
void parse_help (int argc, char** argv, void (*help)(void));

/**
 * Parse arguments with given short and long arg pointers, and call help fn if --help supplied
 * @param argv argument count
 * @param argv argument data
 * @param help fn pointer to call and display fn specific help msg
 * @param short_arg fn pointer to check char after a -, 2nd char* is the next unparsed argv for something like -s [str]
 * @param long_arg fn pointer to check string after a --, 2nd char* is the next unparsed argv for something like --string [str]
 * @returns argc where arguments ended
 */
int parse_args (int argc, char** argv, void (*help)(void), int (*short_arg)(char, char*), int (*long_arg)(char*, char*));

/*
 * Open a file with a given path and type, and print error if failed
 * @param path the path to the file
 * @param type the mode to open the file with
 * @return the file pointer if opened, NULL if failed
 */
FILE* get_file_s(const char* path, const char* type);

/*
 * Open a file with a given path and type, and print error and die if failed
 * @param path the path to the file
 * @param type the mode to open the file with
 * @return the file pointer
 */
FILE* get_file(const char* path, const char* type);

/**
 * Open a tty and error and die if failed
 * @return the file descripter to the tty
 */ 
int get_tty(void);

/**
 * Open a tty stream with the given mode and error and die if failed
 * @param type the mode to open the tty with
 * @return the file pointer to the tty
 */
FILE* get_tty_stream(char* type);

/**
 * Get a reference to the first path buffer
 * @return the pointer to the first path buffer
 */
char* get_path_buffer(void);

/**
 * Push a string to the first path buffer, a / as added before string if it doesnt allready exist at the end
 * @param stirng the local file path to push to the first path buffer
 * @return the integer index to revert to then done
 */
int push_path_buffer(const char* string);

/**
 * Revert the first path buffer to the index provided by push_path_buffer
 * @param i the index to revert to
 */
void pop_path_buffer(int i);

/**
 * Get a reference to the second path buffer
 * @return the pointer to the second path buffer
 */
char* get_path_buffer_2(void);

/**
 * Push a string to the second path buffer, a / as added before string if it doesnt allready exist at the end
 * @param stirng the local file path to push to the first path buffer
 * @return the integer index to revert to then done
 */
int push_path_buffer_2(const char* string);

/**
 * Revert the second path buffer to the index provided by push_path_buffer_2
 * @param i the index to revert to
 */
void pop_path_buffer_2(int i);

/**
 * Get a base 10 number from a string and error and die if failed
 * @param text the string that contains the number
 * @return the parsed integer if successfull
 */
long int get_number(const char* text);

/**
 * Get a blkm (1024m, 38b, 26G) from a string and error and die if failed
 * @param text the string that contains the blkm
 * @return the blkm in bytes if successfull
 */
long int get_blkm(const char* text);

/**
 * Get a mode_t from a string and error and die if failed
 * @param text the string that contains the mode_t
 * @return the mode_t if successfull
 */
mode_t get_mode(const char* text);

/**
 * Check if two strings are exactly equal
 * @param a null terminated string a
 * @param b null terminated string b
 * @returns true if the two strings are exactly equal else false
 */
bool streql(const char* a, const char* b);

/**
 * Check if a string has a given prefix
 * @param pre the null terminated prefix
 * @param str the null terminated string
 * @returns true if str is prefixed with pre else false
 */
bool prefix(const char* pre, const char* str);

/**
 * Put a human redable file size (1024M) into buf with the given byte count
 * @param bytes the byte count
 * @param buf a char buf of length 5 to contain the parsed size
 */
void print_file_size(size_t bytes, char buf[5]);

/**
 * Put a human redable date into buf with the given mills since unix epoch
 * @param mills mills since the unix epoch
 * @param buf a char buf of length 13 to contain the parsed date
 */
void print_date_time(time_t mills, char buf[13]);

/**
 * Print a given file path to stdout or (standard input) if '-'
 * @param path the file path
 */
void print_file_path(char* path);

/**
* Nuke a given string in memory
* @param the stirng to nuke
*/
void nuke_str(char* type);

/**
 * Checks if a given character is printable symbol
 * @returns if its printable
 */
bool printable_char(char c);

/**
 * Checks if a directory name is . or ..
 * @param path the directory name 
 * @return if a directory is one of the . or .. directorys
 */
bool is_dot_dir(const char* path);

/**
 * Get the last component of a path
 * @param path the path to parse
 * @return a const reference to the last component
 */
const char* get_last_component(const char* path);

/**
* Die
*/
void die (void);

/**
 * Print error message to stdout
 * @param format the format string
 * @param ... the rest of the arguments
 */
__attribute__ ((__format__(printf, 1, 2)))
void error_s(const char* format, ...);

/**
 * Print error message to stdout and die
 * @param format the format string
 * @param ... the rest of the arguments
 */
__attribute__ ((__format__(printf, 1, 2)))
void error(const char* format, ...);

/**
 * Output message as the given command
 * @param format the format string
 * @param ... the rest of the arguments
 */
__attribute__ ((__format__(printf, 1, 2)))
void output(const char* format, ...);

/**
 * Refine the regex as a ADT
 */
typedef struct regex_t* re_t;

/**
 * Compile a given regex pattern
 * @param pattern the regex to compile
 * @return the compiled regex
 */
re_t re_compile(const char* pattern);

/**
 * Match a given regex pattern with the string
 * @param pattern the pattern to match with
 * @param text the text to match
 * @param matchlength a pointer to how much was matched
 * @return the index where the match was found, -1 if nothing matched
 */
int re_matchp(re_t pattern, const char* text, int* matchlength);

/**
 * Compile and match a given regex pattern with the string
 * @param pattern the pattern to compile and match with
 * @param text the text to match
 * @param matchlength a pointer to how much was matched
 * @return the index where the match was found, -1 if nothing matched
 */
int re_match(const char* pattern, const char* text, int* matchlength);

/**
 * A struct containing a stack
 */
struct Stack {
    size_t size;        /* The size of the stack */
    size_t capacity;    /* The capacity of the stack */
    void* data;         /* THe data stored in the stack */ 
};

/**
 * Initalize a stack with a given size
 * @param stack a allocated stack struct to inatalize
 * @param size the initial stack capacity
 */
void stack_init(struct Stack* stack, size_t size);

/**
 * Push data to the stack
 * @param stack the stack to push to
 * @param data the data to push
 * @param len the length of the data to push
 */
void stack_push(struct Stack* stack, void* data, size_t len);

/**
 * Pop the data from the stack (move the pointer back by len doesn't delete)
 * @param stack the stack to pop from
 * @param len the length of the data to pop
 * @return the pointer to the data popped (not yet destroyed until pushed)
 */
void* stack_pop(struct Stack* stack, size_t len);

/**
 * Free a stacks allocated memory
 * @param stack the stack to free
 */
void stack_free(struct Stack* stack);

/**
 * Wrapper function to push a int to the stack
 * @param stack the stack to push to
 * @param value the int to push
 */ 
void stack_push_int(struct Stack* stack, int value); 

/**
 * Wrapper function to pop a int from the stack
 * @param stack the stack to pop from
 * @param value the int pointer to pop
 * @returns if a int was successfully popped
 */
bool stack_pop_int(struct Stack* stack, int* value);

/* The default shell if no shell is provided */
#define DEFAULT_SHELL "/bin/sh"

/* The default PATH env variable */
#define DEFAULT_PATH "/sbin:/usr/sbin:/bin:/usr/bin"

/**
 * Setup the environment variables for a given user
 * @param shell the shell to set
 * @param new_env if to update the env variables according to pw
 * @param clear_env if to remove the old env variables
 * @param pw the user to update from
 */
void setup_environment(const char* shell, bool new_env, bool clear_env, const struct passwd *pw);

/**
 * Exec a shell using the current environment, function will not return
 * @param shell the shell to execute
 * @param loginshell if to set the shell as login
 * @param additional_args additional arguments to pass to the shell command
 */
void exec_shell(const char* shell, bool loginshell, const char** additional_args);

#define PASSWORD_INVALID 0 /* if the password was invalid */
#define PASSWORD_VALID 1 /* if the password was valid */
#define PASSWORD_EMPTY 2 /* if the user has an empty password */

/**
 * Check if a given plaintext password matches the users /etc/shadow hash
 * @param pw the user to check
 * @param plaintext the plaintext password to check
 * @return if the password was invalid, valid, or empty
 */
int check_password(const struct passwd* pw, char* plaintext);

/**
 * Prompt the user for their password and then check the given password
 * @param pw the user to check
 * @param prompt the pompt to give to the user
 * @return if the password was invalid, valid, or empty
 */
int prompt_password(const struct passwd* pw, char* prompt);

/**
 * Set UID and GID to a given user
 * @param user to change to
 */
void change_identity(const struct passwd* pw);

/**
 * Alloc memory and die if failed
 * @param size the amount of memory to allocate in bytes
 * @return the pointer to the allocated data
 */
void* xalloc(size_t size);

/**
 * Realloc memory and die if failed
 * @param ptr the pointer to realloc
 * @param size the new size of the data
 * @return the pointer to the reallocated data
 */
void* xrealloc(void* ptr, size_t size);

/**
 * Alloc memory and zero it, die if failed
 * @param size the amouint of memory to allocate in bytes
 * @return the zeroed pointer to the allocated data
 */
void* xzalloc(size_t size);

/**
 * Set the env, die if failed
 * @param name the key to set
 * @param value to value to set the key to
 */
void xsetenv(const char* name, const char* value);

/**
 * Set the uid, die if failed
 * @param uid the uid to set to
 */
void xsetuid(uid_t uid);

/**
 * Set the gid, die if failed
 * @param gid the gid to set to
 */
void xsetgid(gid_t gid);

/**
 * Get pw by name, die if failed
 * @param name the name of the user to get
 * @return the pw of the given user
 */
struct passwd* xgetpwnam(char* name);

#endif /* SHARED_H */