/* Deshab ping — 终端风格 ICMP Echo 工具
 * 命令行输入 IP 地址，发送 ICMP Echo Request（net_stack.h 共享协议栈）。
 * Esc 键退出返回 DSK。
 */

#include "../../firstInit/ascii_bitmaps.c"
#include "../desktop_app.h"
#include "../net_stack.h"

/* ---- 终端参数 ---- */
#define TERM_COLS  120
#define TERM_ROWS  40
#define TERM_MAX_CHARS (TERM_COLS * TERM_ROWS)
#define CHAR_STEP  12
#define CHAR_H     18
#define PROMPT_STR "ping> "

static da_app_context g_ac;

/* 终端缓冲区 */
static u8  term_ch[TERM_MAX_CHARS];
static u32 term_fg[TERM_MAX_CHARS];
static int term_w = TERM_COLS;
static int term_h = TERM_ROWS;
static int cur_col = 0;
static int cur_row = 0;

/* 输入缓冲 */
static char input_buf[256];
static int input_len = 0;
static int input_cursor = 0;

/* 命令历史 */
#define HIST_SIZE 16
static char history[HIST_SIZE][256];
static int hist_count = 0;
static int hist_idx = 0;

/* 坐标 */
static int term_x, term_y;

static void term_init_layout(void) {
    term_x = 8;
    term_y = DA_TITLEBAR_H + 4;
    int avail_w = (int)g_ac.fb_w - 16;
    int avail_h = (int)g_ac.fb_h - term_y - DA_STATUSBAR_H - 8;
    term_w = avail_w / CHAR_STEP;
    term_h = avail_h / CHAR_H;
    if (term_w < 10) term_w = 10;
    if (term_h < 5) term_h = 5;
    if (term_w > TERM_COLS) term_w = TERM_COLS;
    if (term_h > TERM_ROWS) term_h = TERM_ROWS;
}

static void term_clear(void) {
    for (int i = 0; i < TERM_MAX_CHARS; i++) {
        term_ch[i] = ' ';
        term_fg[i] = DA_TEXT_PRIMARY;
    }
    cur_col = 0; cur_row = 0;
}

static void term_scroll(void) {
    for (int r = 1; r < term_h; r++) {
        for (int c = 0; c < term_w; c++) {
            term_ch[(r-1)*TERM_COLS+c] = term_ch[r*TERM_COLS+c];
            term_fg[(r-1)*TERM_COLS+c] = term_fg[r*TERM_COLS+c];
        }
    }
    for (int c = 0; c < term_w; c++) {
        term_ch[(term_h-1)*TERM_COLS+c] = ' ';
        term_fg[(term_h-1)*TERM_COLS+c] = DA_TEXT_PRIMARY;
    }
    cur_row = term_h - 1; cur_col = 0;
}

static void term_newline(void) {
    cur_col = 0; cur_row++;
    if (cur_row >= term_h) term_scroll();
}

static void term_putc_color(char c, u32 color) {
    if (c == '\n') { term_newline(); return; }
    if (c == '\r') { cur_col = 0; return; }
    if (c == '\t') { int sp = 4 - (cur_col % 4); for (int i = 0; i < sp; i++) term_putc_color(' ', color); return; }
    if (c < ' ' || c > '~') c = '?';
    if (cur_col >= term_w) term_newline();
    int idx = cur_row * TERM_COLS + cur_col;
    term_ch[idx] = (u8)c; term_fg[idx] = color;
    cur_col++;
}

static void term_putc(char c) { term_putc_color(c, DA_TEXT_PRIMARY); }
static void term_puts_color(const char *s, u32 color) { while (*s) term_putc_color(*s++, color); }
static void term_puts(const char *s) { term_puts_color(s, DA_TEXT_PRIMARY); }

/* ---- 绘制 ---- */
static void redraw_all(void) {
    da_fill_bg(&g_ac, DA_BG_PRIMARY);
    da_draw_titlebar(&g_ac, "Ping", (i64)g_ac.fb_w);
    /* 终端字符 */
    for (int r = 0; r < term_h; r++) {
        for (int c = 0; c < term_w; c++) {
            int idx = r * TERM_COLS + c;
            if (term_ch[idx] == ' ') continue;
            da_draw_char(&g_ac, term_ch[idx],
                         term_x + c * CHAR_STEP, term_y + r * CHAR_H,
                         term_fg[idx], DA_BG_PRIMARY);
        }
    }
    /* 光标 */
    if (cur_col < term_w && cur_row < term_h) {
        da_fill_rect(&g_ac, term_x + cur_col * CHAR_STEP,
                     term_y + cur_row * CHAR_H + CHAR_H - 3, 11, 2, DA_ACCENT);
    }
    /* 状态栏 */
    char status[64];
    int p = 0;
    const char *s1 = "ICMP Echo | Esc 退出  ";
    while (*s1) status[p++] = *s1++;
    u8 hh, mm; da_rtc_time(&hh, &mm);
    status[p++] = '0' + hh/10; status[p++] = '0' + hh%10;
    status[p++] = ':'; status[p++] = '0' + mm/10; status[p++] = '0' + mm%10;
    status[p] = 0;
    da_draw_statusbar(&g_ac, status, (i64)g_ac.fb_w, (i64)g_ac.fb_h);
}

/* ---- IP 格式校验 ---- */
static int is_valid_ip(const char *s) {
    int dots = 0, digits = 0;
    while (*s) {
        if (*s == '.') { dots++; digits = 0; }
        else if (*s >= '0' && *s <= '9') { digits++; if (digits > 3) return 0; }
        else return 0;
        s++;
    }
    return dots == 3;
}

/* ---- Ping 实现（net_stack.h） ---- */
static int g_ns_status = 0;  /* 0=未尝试, 1=就绪, <0=失败 */

static int ping_net_ready(void) {
    if (g_ns_status == 1) return 1;
    if (g_ns_status < 0) return 0;
    int rc = ns_init((u64)g_ac.kernel_api);
    g_ns_status = (rc == 0) ? 1 : -1;
    if (rc != 0) {
        term_puts_color("  [错误] 网络初始化失败，无可用网卡或 net API\n", DA_ERROR);
        return 0;
    }
    return 1;
}

static void do_ping(const char *ip_str) {
    u32 ip;
    if (ns_parse_ip(ip_str, &ip) != 0) {
        term_puts_color("  [错误] 无法解析 IP\n", DA_ERROR);
        return;
    }
    if (!ping_net_ready()) return;

    char ipstr[24];
    ns_fmt_ip(ip, ipstr);
    term_puts_color("PING ", DA_PROMPT_COLOR);
    term_puts_color(ipstr, DA_ACCENT_LIGHT);
    term_puts_color(" 32 data bytes\n", DA_TEXT_DIM);

    int sent = 0, recv = 0;
    u32 sum = 0, min = 0xFFFFFFFFu, max = 0;
    for (u16 seq = 1; seq <= 4; seq++) {
        u32 rtt = 0; u8 ttl = 0;
        int rc = ns_ping(ip, seq, 2000, &rtt, &ttl);
        sent++;
        if (rc == 0) {
            recv++;
            sum += rtt;
            if (rtt < min) min = rtt;
            if (rtt > max) max = rtt;
            term_puts("reply from ");
            term_puts(ipstr);
            term_puts(": bytes=32 time=");
            char nb[12]; ns_u32_dec(nb, rtt);
            term_puts(nb);
            term_puts("ms TTL=");
            ns_u32_dec(nb, ttl);
            term_puts(nb);
            term_putc('\n');
        } else if (rc == -1) {
            term_puts_color("ARP 解析失败，目标不可达\n", DA_ERROR);
            break;
        } else {
            term_puts_color("request timed out\n", DA_TEXT_DIM);
        }
        redraw_all();
    }
    char nb[12];
    ns_u32_dec(nb, (u32)sent);
    term_puts_color("--- ", DA_TEXT_DIM);
    term_puts_color(ipstr, DA_TEXT_DIM);
    term_puts_color(" ping statistics ---\n  ", DA_TEXT_DIM);
    term_puts(nb);
    term_puts(" transmitted, ");
    ns_u32_dec(nb, (u32)recv);
    term_puts(nb);
    term_puts(" received, ");
    u32 loss = sent ? (u32)(sent - recv) * 100 / (u32)sent : 100;
    ns_u32_dec(nb, loss);
    term_puts(nb);
    term_puts("% loss");
    if (recv > 0) {
        term_puts(", min/avg/max = ");
        ns_u32_dec(nb, min); term_puts(nb); term_puts("/");
        ns_u32_dec(nb, sum / (u32)recv); term_puts(nb); term_puts("/");
        ns_u32_dec(nb, max); term_puts(nb); term_puts(" ms");
    }
    term_putc('\n');
}

/* ---- 内置命令 ---- */
static int str_eq(const char *a, const char *b) {
    while (*a && *b) { if (*a != *b) return 0; a++; b++; }
    return *a == *b;
}

static void cmd_help(void) {
    term_puts_color("ping — ICMP Echo 请求工具\n", DA_PROMPT_COLOR);
    term_puts("  <IP>         发送 ICMP Echo Request\n");
    term_puts("  help         显示此帮助\n");
    term_puts("  clear        清屏\n");
    term_puts("  version      显示版本\n");
    term_puts("  Esc          退出\n");
}

static void cmd_clear(void) { term_clear(); }

static void cmd_version(void) {
    term_puts_color("Deshab ping v1.0\n", DA_SUCCESS);
    term_puts_color("  ICMP Echo via net_stack (e1000 + slirp)\n", DA_TEXT_DIM);
}

static void execute_command(const char *cmd) {
    while (*cmd == ' ') cmd++;
    if (*cmd == 0) return;

    if (str_eq(cmd, "help") || str_eq(cmd, "?")) { cmd_help(); return; }
    if (str_eq(cmd, "clear") || str_eq(cmd, "cls")) { cmd_clear(); return; }
    if (str_eq(cmd, "version") || str_eq(cmd, "ver")) { cmd_version(); return; }

    /* 非内置命令视为 IP 地址 */
    if (is_valid_ip(cmd)) {
        do_ping(cmd);
    } else {
        term_puts_color("无效 IP 地址: ", DA_ERROR);
        term_puts_color(cmd, DA_ERROR);
        term_putc('\n');
        term_puts_color("请输入有效的 IPv4 地址 (如 192.168.1.1)\n", DA_TEXT_DIM);
    }
}

static void add_history(const char *cmd) {
    if (hist_count < HIST_SIZE) {
        int i;
        for (i = 0; cmd[i] && i < 255; i++) history[hist_count][i] = cmd[i];
        history[hist_count][i] = 0;
        hist_count++;
    }
    hist_idx = hist_count;
}

/* ---- 输入行重绘 ---- */
static void redraw_input_line(void) {
    int plen = 0;
    while (PROMPT_STR[plen]) plen++;
    i64 y = term_y + (i64)cur_row * CHAR_H;
    da_fill_rect(&g_ac, term_x, y, (i64)term_w * CHAR_STEP, CHAR_H, DA_BG_PRIMARY);
    for (int i = 0; i < plen; i++)
        da_draw_char(&g_ac, PROMPT_STR[i], term_x + i * CHAR_STEP, y, DA_PROMPT_COLOR, DA_BG_PRIMARY);
    for (int i = 0; i < input_len; i++)
        da_draw_char(&g_ac, input_buf[i], term_x + (plen + i) * CHAR_STEP, y, DA_TEXT_PRIMARY, DA_BG_PRIMARY);
    cur_col = plen + input_cursor;
    da_fill_rect(&g_ac, term_x + cur_col * CHAR_STEP, y + CHAR_H - 3, 11, 2, DA_ACCENT);
}

/* ---- 主入口 ---- */
__attribute__((visibility("default")))
void dsk_entry(const da_boot_context *ctx) {
    __asm__ volatile("cli");
    da_slog("ping", "boot");

    if (!ctx || ctx->magic != DA_BOOT_MAGIC) {
        da_slog("ping", "bad context");
        for(;;) __asm__("hlt");
    }

    da_init(&g_ac, ctx);
    ns_apply_lease_from_ctx((u64)(const void *)ctx);  /* netman 租约覆盖默认 slirp IP */
    term_init_layout();
    term_clear();

    /* 启动 banner */
    term_puts_color("=== Deshab ping v1.0 ===\n", DA_ACCENT);
    term_puts_color("ICMP Echo 请求工具\n", DA_SUCCESS);
    term_puts_color("输入 IP 地址发送 ping | 输入 'help' 查看帮助 | Esc 退出\n", DA_TEXT_DIM);
    term_putc('\n');

    redraw_all();

    int shift = 0, e0 = 0;
    for (;;) {
        term_puts_color(PROMPT_STR, DA_PROMPT_COLOR);
        input_len = 0; input_cursor = 0; input_buf[0] = 0;
        int plen = 0; while (PROMPT_STR[plen]) plen++;
        cur_col = plen;
        redraw_all();

        int cmd_done = 0;
        while (!cmd_done) {
            u8 st = inb(0x64);
            if (!(st & 1)) { __asm__("pause"); continue; }
            u8 data = inb(0x60);
            if (st & 0x20) continue;
            u8 sc = data;
            if (sc == 0xE0) { e0 = 1; continue; }
            if (sc == 0x2A || sc == 0x36) { shift = 1; continue; }
            if (sc == 0xAA || sc == 0xB6) { shift = 0; continue; }
            if (sc & 0x80) { e0 = 0; continue; }

            /* Esc 退出 */
            if (sc == 0x01 && !e0) {
                da_slog("ping", "exit");
                return;
            }

            if (e0) {
                if (sc == 0x4B) { if (input_cursor > 0) input_cursor--; }
                else if (sc == 0x4D) { if (input_cursor < input_len) input_cursor++; }
                else if (sc == 0x47) { input_cursor = 0; }
                else if (sc == 0x4F) { input_cursor = input_len; }
                else if (sc == 0x48) {
                    if (hist_idx > 0) {
                        hist_idx--;
                        int i; for (i = 0; history[hist_idx][i] && i < 255; i++) input_buf[i] = history[hist_idx][i];
                        input_len = i; input_cursor = i; input_buf[i] = 0;
                    }
                }
                else if (sc == 0x50) {
                    if (hist_idx < hist_count - 1) {
                        hist_idx++;
                        int i; for (i = 0; history[hist_idx][i] && i < 255; i++) input_buf[i] = history[hist_idx][i];
                        input_len = i; input_cursor = i; input_buf[i] = 0;
                    } else if (hist_idx < hist_count) {
                        hist_idx = hist_count;
                        input_len = 0; input_cursor = 0; input_buf[0] = 0;
                    }
                }
                e0 = 0;
                redraw_input_line();
                continue;
            }

            if (sc == 0x1C) { /* Enter */
                input_buf[input_len] = 0;
                term_putc('\n');
                if (input_len > 0) add_history(input_buf);
                execute_command(input_buf);
                cmd_done = 1;
                continue;
            }
            if (sc == 0x0E) { /* Backspace */
                if (input_cursor > 0) {
                    for (int i = input_cursor - 1; i < input_len - 1; i++)
                        input_buf[i] = input_buf[i+1];
                    input_len--; input_cursor--;
                    input_buf[input_len] = 0;
                }
                redraw_input_line();
                continue;
            }
            char c = da_scan_to_ascii(sc, shift);
            if (c && c >= 32 && c <= 126 && input_len < 255) {
                for (int i = input_len; i > input_cursor; i--)
                    input_buf[i] = input_buf[i-1];
                input_buf[input_cursor++] = c;
                input_len++;
                redraw_input_line();
            }
        }
        redraw_all();
    }
}