import base64
import json
import os
import re
import subprocess
import sys
from pathlib import Path

from drives import list_scored_devices
from flask import Flask, jsonify, redirect, render_template, request, url_for

app = Flask(__name__)

LANGUAGES = {
    "en": {"locale": "en_US.UTF-8", "label": "English", "keyboard": "us"},
    "de": {"locale": "de_DE.UTF-8", "label": "Deutsch", "keyboard": "de"},
    "pl": {"locale": "pl_PL.UTF-8", "label": "Polski", "keyboard": "pl"},
}

STATE_DIR = Path(os.environ.get("FURTKA_STATE_DIR", "/tmp/furtka"))
INSTALL_LOG = STATE_DIR / "install.log"
CONFIG_PATH = STATE_DIR / "user_configuration.json"
CREDS_PATH = STATE_DIR / "user_credentials.json"

# Pre-populated with sane defaults so the form has something useful on first
# render. POSTs validate and overwrite.
settings = {
    "hostname": "furtka",
    "username": "",
    "password": "",
    "language": "en",
    "boot_drive": "",
}

HOSTNAME_RE = re.compile(r"^[a-z0-9]([a-z0-9-]{0,61}[a-z0-9])?$")
USERNAME_RE = re.compile(r"^[a-z_][a-z0-9_-]{0,31}$")

# Ordered phase markers for the install progress bar. Each tuple is
# (substring to search for in the archinstall log, progress percent when
# reached, user-facing label). Pick the furthest phase whose marker is
# present in the log. If archinstall changes its stdout wording the bar
# stalls on the last recognized phase — the install itself keeps going.
PROGRESS_PHASES = [
    ("Wiping partitions", 8, "Preparing your disk"),
    ("Creating partitions", 12, "Creating partitions"),
    ("Starting installation", 15, "Starting installation"),
    ("Waiting for", 18, "Syncing time and packages"),
    ("Installing packages: ['base'", 25, "Installing the base system (this takes a while)"),
    ("Adding bootloader", 65, "Setting up boot"),
    ("Installing packages: ['efibootmgr'", 70, "Setting up boot"),
    ("Installing packages: ['docker'", 80, "Installing your apps"),
    ("Enabling service", 90, "Turning on services"),
    ("Updating /mnt/etc/fstab", 95, "Almost done"),
    ("Installation completed without any errors", 100, "Done!"),
]

PROGRESS_ERROR_MARKERS = ("Traceback (most recent call last)", "archinstall: error:")


def parse_install_progress(log):
    percent = 2
    phase = "Starting up…"
    for marker, pct, label in PROGRESS_PHASES:
        if marker in log:
            percent = pct
            phase = label

    if percent >= 100:
        status = "done"
    elif any(m in log for m in PROGRESS_ERROR_MARKERS):
        status = "error"
        phase = "Installation failed — open Show details below"
    else:
        status = "running"

    return {"percent": percent, "phase": phase, "status": status}


def validate_step1(form):
    errors = []
    values = {
        "hostname": form.get("hostname", "").strip(),
        "username": form.get("username", "").strip(),
        "password": form.get("password", ""),
        "language": form.get("language", ""),
    }
    password2 = form.get("password2", "")

    if not HOSTNAME_RE.match(values["hostname"]):
        errors.append("Hostname must be lowercase letters, digits, hyphens (max 63 chars).")
    if not USERNAME_RE.match(values["username"]):
        errors.append("Username must start with a letter or underscore, lowercase only.")
    if len(values["password"]) < 8:
        errors.append("Password must be at least 8 characters.")
    if values["password"] != password2:
        errors.append("Passwords do not match.")
    if values["language"] not in LANGUAGES:
        errors.append("Pick a language.")
    return errors, values


def build_disk_config(boot_drive):
    # archinstall 4.x dropped the `use_entire_disk` shortcut — `default_layout`
    # now requires fully-specified partitions. We call suggest_single_disk_layout
    # with ext4 + no separate /home, which short-circuits its interactive prompts.
    import asyncio

    from archinstall.lib.disk.device_handler import device_handler
    from archinstall.lib.disk.disk_menu import suggest_single_disk_layout
    from archinstall.lib.models.device import (
        DiskLayoutConfiguration,
        DiskLayoutType,
        FilesystemType,
    )

    device_handler.load_devices()
    device = device_handler.get_device(Path(boot_drive))
    if device is None:
        raise RuntimeError(f"archinstall could not resolve device {boot_drive!r}")

    device_mod = asyncio.run(
        suggest_single_disk_layout(
            device,
            filesystem_type=FilesystemType.Ext4,
            separate_home=False,
        )
    )
    layout = DiskLayoutConfiguration(
        config_type=DiskLayoutType.Default,
        device_modifications=[device_mod],
    )
    return layout.json()


# ---------------------------------------------------------------------------
# Post-install bootstrap payload
#
# Written into the target system via archinstall's `custom_commands` so that
# after reboot the user lands in "Furtka": Caddy serves a branded landing
# page + live status tiles on :80, avahi advertises proksi.local, and the
# console shows a welcome banner pointing at the URL.
#
# Files are shipped inline (base64-encoded) rather than copied from the live
# ISO because archinstall's chroot can't see the live filesystem. Payload is
# small (~200 lines across 9 files) so this is cheaper than a tarball dance.
# ---------------------------------------------------------------------------

_CADDYFILE = """\
# Serves the Furtka landing page + status.json on :80. Static for the
# landing page; /apps and /api are reverse-proxied to the local resource-
# manager API (furtka serve, bound to 127.0.0.1:7000). TLS / auth come
# later when Authentik is wired in.
:80 {
\thandle /api/* {
\t\treverse_proxy localhost:7000
\t}
\thandle /apps* {
\t\treverse_proxy localhost:7000
\t}
\thandle {
\t\troot * /srv/furtka/www
\t\tfile_server
\t\tencode gzip
\t}
\tlog {
\t\toutput stdout
\t}
}
"""

_INDEX_HTML = """\
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <title>Furtka</title>
    <meta name="viewport" content="width=device-width,initial-scale=1">
    <link rel="stylesheet" href="/style.css">
</head>
<body>
    <main>
        <header>
            <h1>Welcome to Furtka</h1>
            <p class="lead">Your home server is ready.</p>
            <p class="host">Running on <code>__HOSTNAME__</code></p>
        </header>

        <section class="status">
            <h2>System status</h2>
            <div class="tiles">
                <div class="tile">
                    <span class="label">Uptime</span>
                    <span class="value" id="uptime">—</span>
                </div>
                <div class="tile">
                    <span class="label">Docker</span>
                    <span class="value" id="docker">—</span>
                </div>
                <div class="tile">
                    <span class="label">Free disk</span>
                    <span class="value" id="disk">—</span>
                </div>
            </div>
            <p class="updated">Updated <span id="updated">—</span></p>
        </section>

        <section class="soon">
            <h2>Apps</h2>
            <p><a href="/apps">Manage installed apps →</a></p>
        </section>

        <footer>
            <p>Furtka · <a href="https://furtka.org">furtka.org</a></p>
        </footer>
    </main>

    <script>
        async function refresh() {
            try {
                const r = await fetch('/status.json', {cache: 'no-store'});
                if (!r.ok) return;
                const s = await r.json();
                document.getElementById('uptime').textContent = s.uptime || '—';
                document.getElementById('docker').textContent = s.docker_version || '—';
                document.getElementById('disk').textContent = s.disk_free || '—';
                document.getElementById('updated').textContent = s.updated_at || '—';
            } catch (e) {
                /* next tick will retry */
            }
        }
        refresh();
        setInterval(refresh, 15000);
    </script>
</body>
</html>
"""

_STYLE_CSS = """\
:root {
    --bg: #0f1115;
    --fg: #e8eaed;
    --muted: #9aa0a6;
    --accent: #6ee7b7;
    --card: #1a1d24;
}
* { box-sizing: border-box; }
body {
    margin: 0;
    font-family: system-ui, -apple-system, sans-serif;
    background: var(--bg);
    color: var(--fg);
    line-height: 1.5;
}
main { max-width: 780px; margin: 0 auto; padding: 4rem 1.5rem; }
header h1 { margin: 0 0 0.5rem; font-size: 2.5rem; }
.lead { font-size: 1.25rem; color: var(--muted); margin: 0 0 0.25rem; }
.host { color: var(--muted); margin: 0 0 3rem; }
.host code {
    background: var(--card);
    padding: 0.15rem 0.5rem;
    border-radius: 4px;
    color: var(--accent);
}
section h2 {
    font-size: 1.1rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--muted);
    margin: 2rem 0 1rem;
}
.tiles {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 1rem;
}
.tile {
    background: var(--card);
    padding: 1.25rem;
    border-radius: 8px;
    display: flex;
    flex-direction: column;
}
.tile .label {
    font-size: 0.8rem;
    color: var(--muted);
    text-transform: uppercase;
    letter-spacing: 0.08em;
}
.tile .value { font-size: 1.25rem; margin-top: 0.5rem; }
.updated { font-size: 0.85rem; color: var(--muted); margin-top: 1rem; }
.soon {
    background: var(--card);
    padding: 1.5rem;
    border-radius: 8px;
    margin-top: 2rem;
}
footer {
    margin-top: 4rem;
    padding-top: 1.5rem;
    border-top: 1px solid #2a2e36;
    color: var(--muted);
    font-size: 0.9rem;
}
footer a { color: var(--accent); }
"""

_STATUS_JSON_PLACEHOLDER = """\
{
  "hostname": "",
  "uptime": "starting…",
  "docker_version": "starting…",
  "disk_free": "starting…",
  "updated_at": ""
}
"""

_FURTKA_STATUS_SH = """\
#!/bin/bash
# Writes /srv/furtka/www/status.json with current system stats. Fired by
# furtka-status.timer every 30s; also runs once 10s after boot.
set -e

out=/srv/furtka/www/status.json
tmp=$(mktemp)

hostname=$(cat /etc/hostname)
uptime=$(uptime -p 2>/dev/null | sed 's/^up //' || echo unknown)
if command -v docker >/dev/null 2>&1; then
    docker_version=$(docker --version 2>/dev/null \
        | awk '{print $3}' | tr -d ',' || echo unavailable)
else
    docker_version=unavailable
fi
disk_free=$(df -h / 2>/dev/null | awk 'NR==2 {print $4 " free of " $2}' || echo unknown)
updated_at=$(date -Iseconds)

cat > "$tmp" <<EOF
{
  "hostname": "$hostname",
  "uptime": "$uptime",
  "docker_version": "$docker_version",
  "disk_free": "$disk_free",
  "updated_at": "$updated_at"
}
EOF

mv "$tmp" "$out"
chmod 644 "$out"
"""

_FURTKA_STATUS_SERVICE = """\
[Unit]
Description=Refresh Furtka system status JSON
After=network-online.target

[Service]
Type=oneshot
ExecStart=/usr/local/bin/furtka-status
"""

_FURTKA_STATUS_TIMER = """\
[Unit]
Description=Refresh Furtka system status every 30s

[Timer]
OnBootSec=10s
OnUnitActiveSec=30s
AccuracySec=5s

[Install]
WantedBy=timers.target
"""

_FURTKA_WELCOME_SH = """\
#!/bin/bash
# Regenerates /etc/issue on the installed system so the console tells the
# user which URL to open. Mirrors the live-ISO furtka-update-issue pattern.
set -e

hostname=$(cat /etc/hostname)
ip=$(ip -4 -o addr show scope global 2>/dev/null | awk '{print $4}' | cut -d/ -f1 | head -1)

{
    echo
    echo "  Furtka is ready."
    echo
    echo "  Open in a browser on another device on your network:"
    echo
    echo "      http://${hostname}.local   (easy — try this first)"
    if [ -n "$ip" ]; then
        echo "      http://${ip}   (fallback if the first doesn't work)"
    fi
    echo
} > /etc/issue

agetty --reload 2>/dev/null || true
"""

_FURTKA_WELCOME_SERVICE = """\
[Unit]
Description=Furtka console welcome banner
After=network-online.target
Wants=network-online.target

[Service]
Type=oneshot
ExecStart=/usr/local/bin/furtka-welcome
RemainAfterExit=yes

[Install]
WantedBy=multi-user.target
"""

# Tarball built by iso/build.sh containing the furtka/ Python package + the
# bundled apps/ tree. The webinstaller reads it from the live ISO at
# request-time and base64-encodes it into a custom_command for archinstall.
RESOURCE_MANAGER_PAYLOAD = Path("/opt/furtka-resource-manager.tar.gz")

_FURTKA_WRAPPER_SH = """\
#!/bin/sh
# Tiny launcher for the furtka resource-manager CLI. The Python source lives
# under /opt/furtka/furtka/ — added to PYTHONPATH so plain `python3 -m` finds
# it without needing pip on the target system.
PYTHONPATH=/opt/furtka exec python3 -m furtka.cli "$@"
"""

_FURTKA_RECONCILE_SERVICE = """\
[Unit]
Description=Furtka app reconciler (boot-scan)
Requires=docker.service
After=docker.service network-online.target
Wants=network-online.target

[Service]
Type=oneshot
ExecStart=/usr/local/bin/furtka reconcile
RemainAfterExit=no

[Install]
WantedBy=multi-user.target
"""

_FURTKA_API_SERVICE = """\
[Unit]
Description=Furtka resource-manager HTTP API + UI
Requires=docker.service
After=docker.service network-online.target furtka-reconcile.service
Wants=network-online.target

[Service]
Type=simple
ExecStart=/usr/local/bin/furtka serve --host 127.0.0.1 --port 7000
Restart=on-failure
RestartSec=5

[Install]
WantedBy=multi-user.target
"""


def _write_file_cmd(path, content, mode=None):
    """Shell command that recreates `path` with `content` inside the chroot.

    Uses base64 so we don't have to worry about bash / JSON / archinstall
    quoting the payload through three layers of shell. `base64` is part of
    coreutils and always available in the target system.
    """
    b64 = base64.b64encode(content.encode()).decode()
    parent = path.rsplit("/", 1)[0]
    cmd = f"mkdir -p {parent} && printf %s {b64} | base64 -d > {path}"
    if mode is not None:
        cmd += f" && chmod {mode} {path}"
    return cmd


def _resource_manager_commands():
    """Commands to land /opt/furtka/ + the `furtka` CLI + reconcile.service.

    Reads the payload tarball staged into the live ISO at build time. If the
    file isn't present (dev box without an ISO build), returns [] so the rest
    of the install still works — the resource manager just won't be installed.
    """
    if not RESOURCE_MANAGER_PAYLOAD.exists():
        print(
            f"warning: {RESOURCE_MANAGER_PAYLOAD} missing, "
            "resource manager will NOT be installed on target",
            file=sys.stderr,
        )
        return []
    payload_b64 = base64.b64encode(RESOURCE_MANAGER_PAYLOAD.read_bytes()).decode()
    untar_cmd = (
        f"mkdir -p /opt/furtka && printf %s {payload_b64} | base64 -d | tar -xzf - -C /opt/furtka"
    )
    return [
        untar_cmd,
        _write_file_cmd("/usr/local/bin/furtka", _FURTKA_WRAPPER_SH, mode="755"),
        _write_file_cmd("/etc/systemd/system/furtka-reconcile.service", _FURTKA_RECONCILE_SERVICE),
        _write_file_cmd("/etc/systemd/system/furtka-api.service", _FURTKA_API_SERVICE),
    ]


def _post_install_commands(hostname):
    # nss-mdns: splice `mdns_minimal [NOTFOUND=return]` before `resolve` on
    # the hosts line so `*.local` works from the installed system too. Guarded
    # so a re-run (or a future Arch default that already ships mdns) is a
    # no-op instead of double-injecting.
    nss_sed = (
        "grep -q 'mdns_minimal' /etc/nsswitch.conf || "
        "sed -i '/^hosts:/ s/resolve/mdns_minimal [NOTFOUND=return] resolve/' "
        "/etc/nsswitch.conf"
    )
    # Pin the chosen hostname into the static HTML at install-time so the
    # landing page doesn't need a server-side template.
    hostname_sed = f"sed -i 's/__HOSTNAME__/{hostname}/g' /srv/furtka/www/index.html"
    return [
        _write_file_cmd("/etc/caddy/Caddyfile", _CADDYFILE),
        _write_file_cmd("/srv/furtka/www/index.html", _INDEX_HTML),
        _write_file_cmd("/srv/furtka/www/style.css", _STYLE_CSS),
        _write_file_cmd("/srv/furtka/www/status.json", _STATUS_JSON_PLACEHOLDER),
        _write_file_cmd("/usr/local/bin/furtka-status", _FURTKA_STATUS_SH, mode="755"),
        _write_file_cmd("/usr/local/bin/furtka-welcome", _FURTKA_WELCOME_SH, mode="755"),
        _write_file_cmd("/etc/systemd/system/furtka-status.service", _FURTKA_STATUS_SERVICE),
        _write_file_cmd("/etc/systemd/system/furtka-status.timer", _FURTKA_STATUS_TIMER),
        _write_file_cmd("/etc/systemd/system/furtka-welcome.service", _FURTKA_WELCOME_SERVICE),
        nss_sed,
        hostname_sed,
        *_resource_manager_commands(),
        # archinstall calls `systemctl enable` on `services` *before*
        # custom_commands runs, so our own unit files aren't on disk yet at
        # that point. Enable them here, after they exist. caddy /
        # avahi-daemon stay in the `services` list — those are packaged
        # units, present right after pacstrap. furtka-reconcile +
        # furtka-api are enabled only if the resource manager payload was
        # actually installed above; the conditional keeps systemctl green
        # on dev / payload-less builds.
        "systemctl enable furtka-welcome.service furtka-status.timer "
        "$([ -e /etc/systemd/system/furtka-reconcile.service ] "
        "&& echo furtka-reconcile.service furtka-api.service)",
    ]


def _detect_bootloader():
    # systemd-boot is UEFI-only; on BIOS/legacy it trips HardwareIncompatibilityError
    # inside archinstall. /sys/firmware/efi exists iff we were booted via UEFI.
    return "Systemd-boot" if Path("/sys/firmware/efi").exists() else "Grub"


def build_archinstall_config(s):
    return {
        "archinstall-language": "English",
        "timezone": "Europe/Berlin",
        "ntp": True,
        "bootloader": _detect_bootloader(),
        "disk_config": build_disk_config(s["boot_drive"]),
        "hostname": s["hostname"],
        "kernels": ["linux"],
        "packages": [
            "docker",
            "docker-compose",
            # Editors for console/SSH recovery — `nano` is the beginner-friendly
            # one, `vim` stays because it's muscle-memory for the dev team.
            "nano",
            "vim",
            "git",
            "htop",
            "curl",
            # Remote access — archinstall 4.x's `ssh: True` flag is flaky about
            # actually pulling in openssh, so list it explicitly and enable sshd
            # via `services` below. Without this, the documented recovery path
            # (SSH in → edit .env) doesn't work.
            "openssh",
            # Base OS post-install (landing page + mDNS on installed system).
            "caddy",
            "avahi",
            "nss-mdns",
            # Resource manager runtime — pure-stdlib Python, no pip needed
            # because we expose the package via PYTHONPATH in /usr/local/bin/furtka.
            "python",
        ],
        "profile": {"type": "server"},
        "services": [
            "docker",
            # Base OS post-install services. Only packaged units go here —
            # archinstall runs `systemctl enable` on this list *before*
            # custom_commands, so our own furtka-welcome + furtka-status.timer
            # units (written in custom_commands) are enabled there instead.
            "caddy",
            "avahi-daemon",
            "sshd",
        ],
        # `gpasswd -a <user> docker` has to stay first — adds the user to
        # the docker group once the group exists (archinstall creates users
        # before pacstrapping extras). After that we drop the Furtka landing
        # page, status timer, and welcome banner into place.
        "custom_commands": [
            f"gpasswd -a {s['username']} docker",
            *_post_install_commands(s["hostname"]),
        ],
        "network_config": {"type": "iso"},
        "ssh": True,
        "audio_config": None,
        "locale_config": {
            "locale": LANGUAGES[s["language"]]["locale"],
            # Keyboard layout follows the chosen language so a German user
            # doesn't get a US layout at the TTY console (where things like
            # `/`, `-`, `=` land on surprising keys and make even `sudo vim`
            # painful). `en` falls through to "us" which is what we want.
            "keyboard_layout": LANGUAGES[s["language"]]["keyboard"],
        },
    }


def build_archinstall_creds(s):
    # archinstall 4.x expects `!root-password` and `!password` (plaintext
    # sentinels). Users with neither `!password` nor `enc_password` are
    # silently dropped by User.parse_arguments — hence login failures.
    return {
        "!root-password": s["password"],
        "users": [
            {
                "username": s["username"],
                "!password": s["password"],
                "sudo": True,
                "groups": [],
            }
        ],
    }


def write_install_files(s, state_dir):
    state_dir.mkdir(parents=True, exist_ok=True)
    config_path = state_dir / "user_configuration.json"
    creds_path = state_dir / "user_credentials.json"
    config_path.write_text(json.dumps(build_archinstall_config(s), indent=2))
    creds_path.write_text(json.dumps(build_archinstall_creds(s), indent=2))
    creds_path.chmod(0o600)
    return config_path, creds_path


def spawn_archinstall(config_path, creds_path, log_path):
    log_fh = open(log_path, "wb")
    return subprocess.Popen(
        [
            "archinstall",
            "--config",
            str(config_path),
            "--creds",
            str(creds_path),
            "--silent",
        ],
        stdout=log_fh,
        stderr=subprocess.STDOUT,
        start_new_session=True,
    )


@app.route("/")
def home():
    return redirect(url_for("install_step_1"))


@app.route("/install/step1", methods=["GET", "POST"])
def install_step_1():
    errors = []
    if request.method == "POST":
        errors, values = validate_step1(request.form)
        if not errors:
            settings.update(values)
            return redirect(url_for("install_step_2"))
        form_values = values
    else:
        form_values = {k: settings[k] for k in ("hostname", "username", "language")}
    return render_template(
        "install/step1.html",
        values=form_values,
        languages=LANGUAGES,
        errors=errors,
    )


@app.route("/install/step2", methods=["GET", "POST"])
def install_step_2():
    if request.method == "POST":
        boot_drive = request.form.get("boot_drive", "").strip()
        if boot_drive:
            settings["boot_drive"] = boot_drive
            return redirect(url_for("install_overview"))
    return render_template(
        "install/step2.html",
        drives=list_scored_devices(),
        selected=settings.get("boot_drive", ""),
    )


@app.route("/install/overview")
def install_overview():
    masked = {**settings, "password": "•" * 8 if settings["password"] else ""}
    return render_template("install/overview.html", settings=masked)


@app.route("/install/run", methods=["POST"])
def install_run():
    if not settings["boot_drive"] or not settings["username"] or not settings["password"]:
        return redirect(url_for("install_step_1"))
    config_path, creds_path = write_install_files(settings, STATE_DIR)
    INSTALL_LOG.write_bytes(b"")
    if os.environ.get("FURTKA_DRY_RUN") == "1":
        INSTALL_LOG.write_text(
            f"DRY RUN: would exec archinstall --config {config_path} "
            f"--creds {creds_path} --silent\n"
        )
    else:
        spawn_archinstall(config_path, creds_path, INSTALL_LOG)
    return redirect(url_for("install_log_view"))


@app.route("/install/log")
def install_log_view():
    log = INSTALL_LOG.read_text() if INSTALL_LOG.exists() else ""
    return render_template(
        "install/log.html",
        log=log,
        progress=parse_install_progress(log),
    )


@app.route("/install/log.json")
def install_log_json():
    log = INSTALL_LOG.read_text() if INSTALL_LOG.exists() else ""
    return jsonify(log=log, progress=parse_install_progress(log))


@app.route("/install/reboot", methods=["POST"])
def install_reboot():
    # Only allow rebooting once the install has actually finished — we don't
    # want a panicked click during install to reboot mid-pacstrap.
    log = INSTALL_LOG.read_text() if INSTALL_LOG.exists() else ""
    if parse_install_progress(log)["status"] != "done":
        return redirect(url_for("install_log_view"))
    # Delay reboot a few seconds so the browser can finish fetching CSS / assets
    # for the rebooting page before the Flask server (and network) go away.
    # Without this, the reboot page renders unstyled (giant inline SVG icon).
    subprocess.Popen(
        ["/bin/sh", "-c", "sleep 3 && /usr/bin/systemctl reboot"],
        start_new_session=True,
    )
    return render_template("install/rebooting.html", hostname=settings["hostname"])


if __name__ == "__main__":
    app.run(debug=True, port=5000)