"""
workflow_serial.py — Serial-based ES24N IOM network configuration workflow.
Connects via USB serial cable, logs in to the IOM console, and configures
network settings by running curl commands through the shell session.

The IOM's Redfish API is only accessible locally at https://127.0.0.1 from
within the IOM's own shell — not directly from the host over the serial cable.
All Redfish operations are therefore performed by issuing curl commands over
the serial connection and parsing the JSON responses.
"""

import glob
import json
import os
import re
import subprocess
import time
from typing import Optional

from models import IOMConfig, ShelfConfig
from serial_port import SerialPort
from ui import (
    _c, C,
    banner, rule, draw_table, draw_box,
    info, ok, warn, error,
    prompt, prompt_ip, prompt_yn, prompt_password,
)

# Strip ANSI escape sequences from serial terminal output
_ANSI_RE = re.compile(r'\x1b\[[0-9;]*[mGKHF]')


# ── Serial Redfish transport ───────────────────────────────────────────────────
def _login_serial_console(ser: SerialPort, password: str) -> bool:
    """
    Perform the root login sequence on the IOM serial console.
    Handles both the case where a login prompt is showing and where
    a shell session is already active.
    Returns True if a shell prompt is reached, False on failure.
    """
    info("Logging in to IOM serial console...")

    # Send a newline to get the current state of the console
    ser.send_line("", delay=0.5)
    response = _ANSI_RE.sub("", ser.read_until_quiet(quiet_period=0.5))
    low = response.lower()

    # Already at a shell prompt — no login needed
    if ("#" in response or "$" in response) and "login" not in low:
        ok("Already at shell prompt.")
        return True

    # Send username if we see a login prompt (or an empty/unknown response)
    if "login" in low or not response.strip():
        ser.send_line("root", delay=0.5)
        response = _ANSI_RE.sub("", ser.read_until_quiet(quiet_period=0.5))

    # Send password
    if "password" in response.lower():
        ser.send_line(password, delay=0.5)
        response = _ANSI_RE.sub("", ser.read_until_quiet(quiet_period=2.0))

    if "#" in response or "$" in response:
        ok("Logged in to IOM console.")
        return True

    error(f"Login failed. Console response: {response.strip()[:120]}")
    return False


def _serial_redfish_request(ser: SerialPort, password: str, method: str,
                             path: str, payload: Optional[dict] = None) -> tuple:
    """
    Issue a Redfish request by running curl on the IOM's serial console.
    The Redfish API is available at https://127.0.0.1 from within the IOM shell.

    Appends -w '\\nHTTP_CODE:%{http_code}' to every curl call so the HTTP
    status can be parsed independently of the response body.

    Returns (success: bool, data: dict | str).
    """
    url = f"https://127.0.0.1{path}"
    cmd = f"curl -sk -u root:{password} -X {method}"
    if payload:
        body = json.dumps(payload, separators=(",", ":"))
        cmd += f" -H 'Content-Type: application/json' -d '{body}'"
    cmd += f" -w '\\nHTTP_CODE:%{{http_code}}' '{url}'"

    ser.send_line(cmd, delay=0.3)
    raw = _ANSI_RE.sub("", ser.read_until_quiet(quiet_period=1.5, timeout=30.0))

    # ── Parse HTTP status code ─────────────────────────────────────────────────
    http_code = 0
    if "HTTP_CODE:" in raw:
        try:
            http_code = int(raw.split("HTTP_CODE:")[-1].strip()[:3])
        except ValueError:
            pass

    # ── Extract JSON body (outermost { ... }) ──────────────────────────────────
    data: dict = {}
    json_start = raw.find("{")
    json_end   = raw.rfind("}") + 1
    if json_start >= 0 and json_end > json_start:
        try:
            data = json.loads(raw[json_start:json_end])
        except json.JSONDecodeError:
            pass

    # ── Determine success ──────────────────────────────────────────────────────
    if http_code >= 400:
        msg = (data.get("error", {}).get("message", "")
               if isinstance(data, dict) else "")
        return False, f"HTTP {http_code}: {msg or raw[json_start:json_start+120]}"

    if http_code >= 200 or data:
        return True, data

    # No HTTP code and no JSON — check for curl-level error
    if "curl:" in raw.lower():
        return False, f"curl error: {raw.strip()[:120]}"

    return True, data


# ── Step 1: Detect serial device ──────────────────────────────────────────────
def detect_serial_device() -> Optional[str]:
    rule("Step 1 of 5 -- Serial Cable & Device Detection")

    print("  Connect the serial cable from the ES24N IOM1 port")
    print("  to the active F-Series controller USB port.")
    print()
    prompt("Press Enter when the cable is connected")

    for attempt in range(1, 4):
        info(f"Scanning for USB serial devices (attempt {attempt}/3)...")
        time.sleep(1)

        # FreeBSD: /dev/ttyU*   Linux: /dev/ttyUSB*, /dev/ttyACM*
        patterns = ["/dev/ttyUSB*", "/dev/ttyACM*", "/dev/ttyU*"]
        ports    = sorted({p for pat in patterns for p in glob.glob(pat)})

        if ports:
            break

        if attempt < 3:
            warn("No device found yet — retrying in 2 seconds...")
            time.sleep(2)

    if not ports:
        error("No USB serial device detected after 3 attempts.")
        print()
        print("  Troubleshooting:")
        print("    - Ensure the serial cable is fully seated at both ends.")
        print("    - Try a different USB port on the controller.")
        print("    - Confirm the ES24N is powered on.")
        return None

    if len(ports) == 1:
        ok(f"Device found: {_c(C.BOLD, ports[0])}")
        _fix_permissions(ports[0])
        return ports[0]

    # Multiple devices — let the user choose
    print()
    draw_table(
        ["#", "Device"],
        [[str(i), p] for i, p in enumerate(ports, 1)],
        [4, 24],
    )
    print()

    while True:
        val = prompt(f"Select device number [1-{len(ports)}]")
        if val.isdigit() and 1 <= int(val) <= len(ports):
            selected = ports[int(val) - 1]
            ok(f"Selected: {_c(C.BOLD, selected)}")
            _fix_permissions(selected)
            return selected
        warn(f"Please enter a number between 1 and {len(ports)}.")


def _fix_permissions(device: str):
    try:
        result = subprocess.run(
            ["sudo", "chown", ":wheel", device],
            capture_output=True, timeout=5,
        )
        if result.returncode == 0:
            ok(f"Permissions updated on {device}")
            return
    except Exception:
        pass
    try:
        os.chmod(device, 0o666)
        ok(f"Permissions updated on {device}")
    except PermissionError:
        warn("Could not update device permissions automatically.")
        warn("If the connection fails, re-run this script with sudo.")


# ── Step 2: Open serial connection & wake IOM console ─────────────────────────
def open_serial_connection(device: str) -> Optional[SerialPort]:
    rule("Step 2 of 5 -- Opening Serial Connection")

    info(f"Opening {device} at 115200 baud (8N1)...")
    ser = SerialPort(device, baudrate=115200, timeout=5.0)

    try:
        ser.open()
    except OSError as e:
        error(str(e))
        return None

    ok(f"Port opened: {device}")
    info("Sending wake signal to IOM console...")

    ser.send_line("", delay=0.5)
    ser.send_line("", delay=0.5)
    response = _ANSI_RE.sub("", ser.read_until_quiet(quiet_period=0.5))

    print()
    if response.strip():
        print(f"  {_c(C.DIM, '+-- IOM Console Response ' + '-' * 31)}")
        for line in response.strip().splitlines():
            print(f"  {_c(C.DIM, '|')}  {line}")
        print(f"  {_c(C.DIM, '+' + '-' * 56)}")
        print()

        low = response.lower()
        if any(kw in low for kw in ("login", "$", "#", "password")):
            ok("IOM console is responsive.")
        else:
            warn("Unexpected response — the IOM may still be booting.")
            warn("You can continue; login will be attempted next.")
    else:
        warn("No response received from IOM console.")
        warn("Login will be attempted after the password is entered.")

    print()
    return ser


# ── Step 3: Fetch & display current IOM network settings ─────────────────────
def fetch_current_config(cfg: ShelfConfig, ser: SerialPort) -> bool:
    """
    Query Redfish for the current network config of both IOMs via curl
    over the serial console session.
    Populates cfg.iom1 / cfg.iom2 with live data.
    Returns True if at least one IOM responded.
    """
    rule("Step 3 of 5 -- Current IOM Network Settings")
    info("Querying Redfish API via serial console...")
    print()

    any_ok = False
    rows   = []
    errors = []

    for iom in ("IOM1", "IOM2"):
        path = f"/redfish/v1/Managers/{iom}/EthernetInterfaces/1"
        ok_flag, data = _serial_redfish_request(ser, cfg.password, "GET", path)

        if ok_flag and isinstance(data, dict):
            any_ok = True

            # Determine mode
            dhcp_enabled = (
                data.get("DHCPv4", {}).get("DHCPEnabled", False) or
                data.get("DHCPv6", {}).get("DHCPEnabled", False)
            )

            # Pull address info — prefer StaticAddresses, fall back to IPv4Addresses
            addrs = data.get("IPv4StaticAddresses") or data.get("IPv4Addresses", [])
            if addrs:
                addr_rec = addrs[0]
                ip      = addr_rec.get("Address",    "--")
                gateway = addr_rec.get("Gateway",    "--")
                netmask = addr_rec.get("SubnetMask", "--")
            else:
                ip = gateway = netmask = "--"

            origin = data.get("IPv4Addresses", [{}])[0].get("AddressOrigin", "Unknown") \
                     if data.get("IPv4Addresses") else ("DHCP" if dhcp_enabled else "Static")

            iom_cfg = IOMConfig(
                iom     = iom,
                dhcp    = dhcp_enabled,
                ip      = ip      if ip      != "--" else "",
                gateway = gateway if gateway != "--" else "",
                netmask = netmask if netmask != "--" else "",
            )
            if iom == "IOM1":
                cfg.iom1 = iom_cfg
            else:
                cfg.iom2 = iom_cfg

            mode_str = f"{_c(C.CYN, 'DHCP')}" if dhcp_enabled else f"{_c(C.GRN, 'Static')}"
            rows.append([iom, mode_str, origin, ip, gateway, netmask])
        else:
            rows.append([iom, _c(C.RED, "No response"), "--", "--", "--", "--"])
            errors.append((iom, str(data)))

    draw_table(
        ["IOM", "Mode", "Origin", "IP Address", "Gateway", "Subnet Mask"],
        rows,
        [5, 10, 8, 16, 16, 16],
    )
    print()

    if errors:
        for iom, err in errors:
            error(f"{iom} query failed: {err}")
        print()

    if not any_ok:
        error("Neither IOM responded to the Redfish query.")
        error("Check that the serial cable is connected and the IOM is booted.")

    return any_ok


# ── Step 4: Prompt user — change config or exit ───────────────────────────────
def collect_network_config(cfg: ShelfConfig) -> bool:
    """
    Show current settings, ask user what to do.
    Returns True to proceed with applying changes, False to skip.
    """
    rule("Step 4 of 5 -- Change Configuration?")

    print(f"    {_c(C.BOLD, '1')}  Change network configuration")
    print(f"    {_c(C.BOLD, '2')}  Leave settings as-is and disconnect")
    print()

    while True:
        choice = prompt("Select option [1/2]")
        if choice in ("1", "2"):
            break
        warn("Please enter 1 or 2.")

    if choice == "2":
        info("No changes requested.")
        return False

    # ── User wants to change settings ─────────────────────────────────────────
    print()
    print("  How should the IOMs be configured?")
    print(f"    {_c(C.BOLD, '1')}  Static IP addresses")
    print(f"    {_c(C.BOLD, '2')}  DHCP")
    print()

    while True:
        mode = prompt("Select mode [1/2]")
        if mode in ("1", "2"):
            break
        warn("Please enter 1 or 2.")

    use_dhcp = (mode == "2")
    print()

    if use_dhcp:
        cfg.iom1 = IOMConfig("IOM1", dhcp=True)
        cfg.iom2 = IOMConfig("IOM2", dhcp=True)
        ok("Both IOMs will be set to DHCP.")
        return True

    # Static — IOM1
    info(f"Static network details for {_c(C.BOLD, 'IOM1')}:")
    iom1_ip = prompt_ip("  IOM1 IP address ")
    iom1_gw = prompt_ip("  IOM1 Gateway    ")
    iom1_nm = prompt_ip("  IOM1 Subnet Mask")
    cfg.iom1 = IOMConfig("IOM1", dhcp=False, ip=iom1_ip, gateway=iom1_gw, netmask=iom1_nm)

    # Static — IOM2
    print()
    info(f"Static network details for {_c(C.BOLD, 'IOM2')}:")
    iom2_ip = prompt_ip("  IOM2 IP address ")

    same = prompt_yn("  Same gateway and subnet mask as IOM1?", default=True)
    if same:
        iom2_gw, iom2_nm = iom1_gw, iom1_nm
    else:
        iom2_gw = prompt_ip("  IOM2 Gateway    ")
        iom2_nm = prompt_ip("  IOM2 Subnet Mask")

    cfg.iom2 = IOMConfig("IOM2", dhcp=False, ip=iom2_ip, gateway=iom2_gw, netmask=iom2_nm)
    return True


# ── Step 5a: Apply configuration via Redfish ──────────────────────────────────
def apply_configuration(cfg: ShelfConfig, ser: SerialPort) -> bool:
    rule("Step 5 of 5 -- Applying Configuration via Redfish API")

    info("Sending Redfish PATCH requests via serial console curl...")
    print()

    results = []
    all_ok  = True
    for iom_cfg in [cfg.iom1, cfg.iom2]:
        success, detail = _apply_iom(cfg.password, iom_cfg, ser)
        status = _c(C.GRN, "OK") if success else _c(C.RED, "FAIL")
        results.append([iom_cfg.iom, status, detail])
        if not success:
            all_ok = False

    draw_table(["IOM", "Result", "Detail"], results, [6, 8, 50])
    print()
    return all_ok


def _apply_iom(password: str, iom_cfg: IOMConfig, ser: SerialPort) -> tuple:
    """
    Apply network config to a single IOM via curl over the serial console.

    DHCP: single PATCH enabling DHCPv4.

    Static: two sequential PATCHes to work around a firmware bug in the
    current ES24N release that prevents disabling DHCP and setting a static
    address in the same request.
      Pass 1 -- set the static IP/gateway/netmask (DHCP still on)
      Pass 2 -- disable DHCP (address is already committed)
    """
    path = f"/redfish/v1/Managers/{iom_cfg.iom}/EthernetInterfaces/1"

    if iom_cfg.dhcp:
        ok_flag, data = _serial_redfish_request(
            ser, password, "PATCH", path,
            {"DHCPv4": {"DHCPEnabled": True}},
        )
        if ok_flag:
            return True, "Configured: DHCP"
        return False, str(data)[:80]

    # Static -- Pass 1: set address while DHCP is still enabled
    info(f"  {iom_cfg.iom} pass 1/2 -- setting static address {iom_cfg.ip}...")
    ok_flag, data = _serial_redfish_request(
        ser, password, "PATCH", path,
        {
            "IPv4StaticAddresses": [{
                "Address":    iom_cfg.ip,
                "Gateway":    iom_cfg.gateway,
                "SubnetMask": iom_cfg.netmask,
            }]
        },
    )
    if not ok_flag:
        return False, f"Pass 1 failed: {str(data)[:70]}"

    # Brief pause to allow the IOM to commit the address before the next call
    time.sleep(1)

    # Static -- Pass 2: disable DHCP now that the static address is committed
    info(f"  {iom_cfg.iom} pass 2/2 -- disabling DHCP...")
    ok_flag, data = _serial_redfish_request(
        ser, password, "PATCH", path,
        {"DHCPv4": {"DHCPEnabled": False}},
    )
    if not ok_flag:
        return False, f"Pass 2 failed: {str(data)[:70]}"

    return True, f"Configured: Static {iom_cfg.ip}"


# ── Step 5b: Print applied-settings summary ───────────────────────────────────
def print_summary(cfg: ShelfConfig, changed: bool):
    rule("Summary")

    def val(iom: IOMConfig, field: str) -> str:
        dhcp_map = {"mode": "DHCP", "ip": "-- (DHCP)", "gateway": "-- (DHCP)", "netmask": "-- (DHCP)"}
        stat_map = {"mode": "Static", "ip": iom.ip, "gateway": iom.gateway, "netmask": iom.netmask}
        return (dhcp_map if iom.dhcp else stat_map).get(field, "")

    draw_table(
        ["Setting",      "IOM1",                    "IOM2"],
        [
            ["Mode",        val(cfg.iom1, "mode"),    val(cfg.iom2, "mode")],
            ["IP Address",  val(cfg.iom1, "ip"),      val(cfg.iom2, "ip")],
            ["Gateway",     val(cfg.iom1, "gateway"), val(cfg.iom2, "gateway")],
            ["Subnet Mask", val(cfg.iom1, "netmask"), val(cfg.iom2, "netmask")],
            ["Serial Port", cfg.device,               cfg.device],
            ["Changes",     "Yes" if changed else "None", ""],
        ],
        [12, 22, 22],
    )

    if changed:
        print()
        draw_box([
            f"{_c(C.YEL, 'IMPORTANT -- Per the ES24N Service Guide:')}",
            "",
            "Remove the serial cable ONLY after verifying each",
            "expander appears in TrueNAS with matching drives.",
            "",
            "TrueNAS > System Settings > Enclosure >",
            "NVMe-oF Expansion Shelves",
        ], colour=C.YEL)
    print()


# ── Disconnect ────────────────────────────────────────────────────────────────
def close_serial_connection(ser: SerialPort, device: str):
    if ser and ser.is_open:
        ser.close()
        ok(f"Serial port {device} closed.")

    print()
    prompt("Disconnect the serial cable, then press Enter to continue")
    ok("Serial cable disconnected. Shelf complete.")


# ── Full shelf configuration cycle ────────────────────────────────────────────
def configure_shelf() -> bool:
    """Run one complete shelf cycle. Returns True if user wants another shelf."""
    banner()
    cfg = ShelfConfig()

    # 1 — Detect device
    device = detect_serial_device()
    if not device:
        error("Could not detect a serial device. Returning to main menu.")
        time.sleep(2)
        return True
    cfg.device = device

    # 2 — Open serial port & wake IOM console
    ser = open_serial_connection(device)
    if not ser:
        error("Could not open serial port. Returning to main menu.")
        time.sleep(2)
        return True

    # Password needed before login
    print()
    cfg.password = prompt_password()

    # Log in to the IOM console (required before any Redfish curl calls)
    if not _login_serial_console(ser, cfg.password):
        error("Could not log in to IOM console. Returning to main menu.")
        close_serial_connection(ser, device)
        time.sleep(2)
        return True

    # 3 — Fetch & display current settings
    fetch_current_config(cfg, ser)

    # 4 — Ask user: change or leave alone?
    apply_changes = collect_network_config(cfg)

    # 5 — Apply if requested
    changed = False
    if apply_changes:
        print()
        rule("Ready to Apply")
        info("Redfish PATCH requests will be sent via curl on the IOM console.")
        print()
        if prompt_yn("Apply configuration now?", default=True):
            apply_configuration(cfg, ser)
            changed = True
        else:
            warn("Configuration skipped — no changes were made.")

    # Summary
    print_summary(cfg, changed)

    # Disconnect
    close_serial_connection(ser, device)

    print()
    return prompt_yn("Configure another ES24N shelf?", default=False)