// enable "vasprintf" from stdio.h
#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif

#include "console/console.h"

#include <stdio.h>
#include <stdbool.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>

// These are either implemented using unix file descriptors, or in a platform specific way through a void* context
// - then the user code must provide the implementations.
#if CONSOLE_USE_FILE_IO_STREAMS
#include <unistd.h>

bool console_have_stdin_ctx(console_ctx_t *ctx)
{
    return ctx && ctx->in &&
        !feof(ctx->in);
}

/**
 * Write to console context.
 *
 * This is also a Linenoise write callback.
 *
 * Return number of characters written, -1 on error.
 */
int __attribute__((weak)) console_write_ctx(console_ctx_t *ctx, const char *text, size_t len) {
    if (!ctx || !ctx->out) {
        return -1;
    }

    size_t written = fwrite(text, 1, len, ctx->out);
    if (written != len) {
        return -1;
    }

    return (int) written;
}

/**
 * Read from console context's input stream.
 *
 * This is also a Linenoise read callback.
 *
 * Return number of characters read, -1 on error
 */
int __attribute__((weak)) console_read_ctx(console_ctx_t *ctx, char *dest, size_t count) {
    if (!console_have_stdin_ctx(ctx)) return -1;
    ssize_t readn = fread(dest, 1, (size_t) count, ctx->in);
    return (int) readn;
}

#if CONSOLE_USE_TERMIOS
#include <termio.h>

int console_can_read_ctx(console_ctx_t *ctx) {
    if (!console_have_stdin_ctx(ctx)) return -1;

    int fd = fileno(ctx->in);

    struct termios original;
    tcgetattr(fd, &original);

    struct termios term;
    memcpy(&term, &original, sizeof(term));

    term.c_lflag &= ~ICANON;
    tcsetattr(fd, TCSANOW, &term);

    int characters_buffered = 0;
    ioctl(fd, FIONREAD, &characters_buffered);

    tcsetattr(fd, TCSANOW, &original);

    return characters_buffered;
}
#endif // CONSOLE_USE_TERMIOS

#endif // CONSOLE_USE_FILEDES_IO

ssize_t console_printf_ctx(console_ctx_t *ctx, console_color_t color, const char *format, ...) {
    if (!ctx) return -1;
    va_list list;
    va_start(list, format);
    ssize_t len = console_vprintf_ctx(ctx, color, format, list);
    va_end(list);
    return len;
}

ssize_t console_vprintf_ctx(console_ctx_t *ctx, console_color_t color, const char *format, va_list args) {
    if (!ctx) return -1;

    if (ctx->use_colors && color != COLOR_RESET) {
        switch(color) {
            case COLOR_BLACK:
                console_write_ctx(ctx, "\x1b[30;1m", 7);
                break;
            case COLOR_RED:
                console_write_ctx(ctx, "\x1b[31;1m", 7);
                break;
            case COLOR_GREEN:
                console_write_ctx(ctx, "\x1b[32;1m", 7);
                break;
            case COLOR_YELLOW:
                console_write_ctx(ctx, "\x1b[33;1m", 7);
                break;
            case COLOR_BLUE:
                console_write_ctx(ctx, "\x1b[34;1m", 7);
                break;
            case COLOR_MAGENTA:
                console_write_ctx(ctx, "\x1b[35;1m", 7);
                break;
            case COLOR_CYAN:
                console_write_ctx(ctx, "\x1b[36;1m", 7);
                break;
                //case COLOR_WHITE:
            default:
                console_write_ctx(ctx, "\x1b[37;1m", 7);
                break;
        }
    }

    char *buf = NULL;
    ssize_t len = vasprintf(&buf, format, args);
    if (buf && len >= 0) {
        // change to actual len written, can also result in -1 on error
        len = console_write_ctx(ctx, buf, (size_t) len);
        free(buf); // allocated by vasprintf
    }

    if (ctx->use_colors && color != COLOR_RESET) {
        console_write_ctx(ctx, "\x1b[0m", 4);
        len += 7+4;
    }
    return len;
}

int console_print_ctx(console_ctx_t *ctx, const char *text) {
    if (!ctx) return -1;

    return console_write_ctx(ctx, text, (int) strlen(text));
}

ssize_t console_println_ctx(console_ctx_t *ctx, const char *text) {
    if (!ctx) return -1;

    ssize_t n = console_write_ctx(ctx, text, (int) strlen(text));
    if (n < 0) return n;
    ssize_t m = console_write_ctx(ctx, "\n", 2);
    if (m < 0) return m;
    return n + m;
}

// ---------------- convenience functions -------------------

bool console_have_stdin(void) {
    if (!console_context_available()) return false;
    return console_have_stdin_ctx(console_active_ctx);
}

int console_can_read(void) {
    if (!console_have_stdin()) return -1; // Input not available
    return console_can_read_ctx(console_active_ctx);
}

/**
 * Linenoise read callback.
 *
 * Return number of characters read, -1 on error
 */
ssize_t vconsole_read(char *dest, size_t count) {
    if (!console_have_stdin()) return -1;
    return console_read_ctx(console_active_ctx, dest, count);
}

/**
 * Linenoise write callback.
 *
 * Return number of characters written, -1 on error.
 */
ssize_t vconsole_write(const char *text, size_t len) {
    if (!console_context_available()) return -1;
    return console_write_ctx(console_active_ctx, text, len);
}

ssize_t console_println(const char *text) {
    if (!console_context_available()) return -1;
    return console_println_ctx(console_active_ctx, text);
}