#include "tlibc/term.h"
#if defined(_WIN64) || defined(_WIN32)
    #include <windows.h>
    #define try_win_bool(EXPR) if(!(EXPR)) { Return RESULT_ERROR_FMT(#EXPR " failed with WindowsError %lu", GetLastError()); } 
#else
    #include <unistd.h>
    #include <sys/ioctl.h>
    #include <termios.h>
    #define try_zero_errno(EXPR) if((EXPR) != 0) { \
        char* errno_s = strerror_malloc(errno); \
        ResultVar(void) err = RESULT_ERROR_FMT(#EXPR " failed with errno: %s", strerror(errno)); \
        free(errno_s); \
        Return err; \
    } 
#endif

Result(void) term_init(){
    Deferral(8);

#if defined(_WIN64) || defined(_WIN32)
    DWORD mode = 0;
    HANDLE console_handle;

    // configure stdout
    console_handle = GetStdHandle(STD_OUTPUT_HANDLE);
    try_assert(console_handle != INVALID_HANDLE_VALUE);
    GetConsoleMode(console_handle, &mode);
    // https://learn.microsoft.com/en-us/windows/console/setconsolemode
    mode |= ENABLE_VIRTUAL_TERMINAL_PROCESSING;
    mode |= ENABLE_PROCESSED_OUTPUT;
    mode |= DISABLE_NEWLINE_AUTO_RETURN;
    SetConsoleMode(console_handle, mode);
    
    // configure stderr
    console_handle = GetStdHandle(STD_ERROR_HANDLE);
    try_assert(console_handle != INVALID_HANDLE_VALUE);
    GetConsoleMode(console_handle, &mode);
    mode |= ENABLE_VIRTUAL_TERMINAL_PROCESSING;
    mode |= ENABLE_PROCESSED_OUTPUT;
    mode |= DISABLE_NEWLINE_AUTO_RETURN;
    SetConsoleMode(console_handle, mode);

    // configure stdin
    console_handle = GetStdHandle(STD_INPUT_HANDLE);
    try_assert(console_handle != INVALID_HANDLE_VALUE);
    GetConsoleMode(console_handle, &mode);
    mode |= ENABLE_VIRTUAL_TERMINAL_INPUT;
    SetConsoleMode(console_handle, mode);
#endif

    Return RESULT_VOID;
}

i64 getenv_int(const char* var_name){
    char* s = getenv(var_name);
    if(s == NULL)
        return -1;
    return strtoll(s, NULL, 0);
}

Result(void) term_getSize(TerminalSize* out) {
    Deferral(4);

#if defined(_WIN64) || defined(_WIN32)
    // helps when STD_OUT is redirected to a file
    HANDLE console_handle_stderr = GetStdHandle(STD_ERROR_HANDLE);
    try_assert(console_handle_stderr != INVALID_HANDLE_VALUE)
    CONSOLE_SCREEN_BUFFER_INFO consoleInfo;
    try_win_bool(GetConsoleScreenBufferInfo(console_handle_stderr, &consoleInfo));
    
    out->cols = consoleInfo.srWindow.Right - consoleInfo.srWindow.Left + 1;
    out->rows = consoleInfo.srWindow.Bottom - consoleInfo.srWindow.Top + 1;
#else
    struct winsize ws = {0};
    // try to get terminal size from stdin, stdout, stderr
    if (ioctl(STDIN_FILENO,  TIOCGWINSZ, &ws) == 0 ||
        ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) == 0 ||
        ioctl(STDERR_FILENO, TIOCGWINSZ, &ws) == 0 ){
        out->cols = ws.ws_col;
        out->rows = ws.ws_row;
    }
    // try to get size from environtent variables
    else {
        out->cols = getenv_int("COLUMNS");
        out->rows = getenv_int("LINES");
    }
#endif

    try_assert(out->cols > 0);
    try_assert(out->rows > 0);
    Return RESULT_VOID;
}

Result(void) term_readLine(char* buf, u32 bufsize) {
    Deferral(1);
    if(fgets(buf, bufsize, stdin) == NULL){
        try_stderrcode(ferror(stdin));
    }
    Return RESULT_VOID;
}

Result(void) term_readLineHidden(char *buf, u32 bufsize) { 
    Deferral(4);

#if defined(_WIN64) || defined(_WIN32)
    HANDLE console_handle_stdin = GetStdHandle(STD_INPUT_HANDLE); 
    try_assert(console_handle_stdin != INVALID_HANDLE_VALUE); 
    DWORD old_mode; 
    GetConsoleMode(console_handle_stdin, &old_mode); 
    // turn off echo
    DWORD new_mode = old_mode & ~(ENABLE_ECHO_INPUT); 
    SetConsoleMode(console_handle_stdin, new_mode);
    // restore echo
    Defer(SetConsoleMode(console_handle_stdin, old_mode));
#else
    struct termios old_mode, new_mode;
    try_zero_errno(tcgetattr(STDIN_FILENO, &old_mode));
    new_mode = old_mode;
    // turn off echo
    new_mode.c_lflag &= ~(ECHO);
    try_zero_errno(tcsetattr(STDIN_FILENO, TCSAFLUSH, &new_mode));
    // restore echo
    Defer(tcsetattr(STDIN_FILENO, TCSAFLUSH, &old_mode));
#endif
    // read line
    try_void(term_readLine(buf, bufsize));
    fputc('\n', stdout);

    Return RESULT_VOID; 
} 

/*
Most of escape sequences can be found there
https://gist.github.com/fnky/458719343aabd01cfb17a3a4f7296797
*/
#define ESC "\x1b"
#define CSI ESC"["

void term_setFgColor16(Color16 c){
    printf(CSI"%um", c);
}

void term_setBgColor16(Color16 c){
    printf(CSI"%um", c + 10);
}

void term_bold(){
    printf(CSI"1m");
}

void term_italic(){
    printf(CSI"3m");
}

void term_underline(){
    printf(CSI"4m");
}

void term_strikethrough(){
    printf(CSI"9m");
}

void term_resetCursor() {
    printf(CSI"H");
}

void term_resetColors() {
    printf(CSI"0m");
}

void term_clear() {
    printf(CSI"0m" CSI"H" CSI"2J");
}

void term_eraseRow(){
    printf(CSI"2K\r");
}

void term_cursorMove(u16 row, u16 column) {
    printf(CSI"%u;%uH", row, column);
}

void term_cursorHide() {
    printf(CSI"?25l");
}

void term_cursorShow() {
    printf(CSI"?25h");
}