import html
import os
from pathlib import Path

from fastapi import APIRouter, Depends, Form, HTTPException, Request
from fastapi.responses import HTMLResponse, RedirectResponse

from app.auth import require_user
from app.db.alerting import (
    create_alert_rule,
    delete_alert_rule,
    get_alert_event,
    get_alert_events,
    get_alert_rule,
    get_alert_rules,
    get_rule_alert_events,
    set_alert_rule_enabled,
    update_alert_rule,
)
from app.db.audit import log_audit_event
from app.routes.jobs import pretty_json
from app.templates.layout import page

router = APIRouter()

ALERTS_DIR = Path("/opt/appfactory/workspace/appfactory-tools/alerts")
MAX_SCRIPT_BYTES = 100 * 1024
EVENT_TYPES = ("incident.opened", "incident.resolved")
DEFAULT_SCRIPT_CONTENT = """#!/usr/bin/env bash
set -euo pipefail

echo "TODO"
"""


def clean_optional(value: str | None) -> str:
    return (value or "").strip()


def is_admin(user) -> bool:
    return (user.get("role") or "").lower() == "admin"


def render_enabled_pill(value) -> str:
    if value:
        return '<span class="pill pill-success">zapnuto</span>'
    return '<span class="pill pill-muted">vypnuto</span>'


def render_status(value: str | None) -> str:
    status = (value or "").lower()
    if status in {"success", "processed", "done", "ok"}:
        return '<span class="pill pill-success">zpracováno</span>'
    if status in {"queued", "running", "pending"}:
        return '<span class="pill pill-warning">čeká</span>'
    if status in {"failed", "error"}:
        return '<span class="pill pill-danger">selhalo</span>'
    if not status:
        return '<span class="pill pill-muted">bez stavu</span>'
    return f'<span class="pill pill-muted">{html.escape(value or "")}</span>'


def render_event_type_options(selected: str) -> str:
    options = []
    for event_type in EVENT_TYPES:
        selected_attr = " selected" if selected == event_type else ""
        escaped = html.escape(event_type)
        options.append(f'<option value="{escaped}"{selected_attr}>{escaped}</option>')
    return "".join(options)


def validate_event_type(value: str) -> str:
    event_type = clean_optional(value)
    if event_type not in EVENT_TYPES:
        raise HTTPException(status_code=400, detail="Neplatný typ události")
    return event_type


def validate_script_name(value: str) -> str:
    script_name = clean_optional(value)
    if not script_name:
        raise HTTPException(status_code=400, detail="Název skriptu je povinný")
    if not script_name.endswith(".sh"):
        raise HTTPException(status_code=400, detail="Název skriptu musí končit .sh")
    if "/" in script_name or "\\" in script_name or ".." in script_name:
        raise HTTPException(status_code=400, detail="Název skriptu nesmí obsahovat cestu")
    return script_name


def script_path(script_name: str) -> Path:
    safe_name = validate_script_name(script_name)
    path = (ALERTS_DIR / safe_name).resolve()
    base = ALERTS_DIR.resolve()
    try:
        path.relative_to(base)
    except ValueError:
        raise HTTPException(status_code=400, detail="Neplatný název skriptu")
    return path


def read_script_file(script_name: str) -> dict:
    path = script_path(script_name)
    if not path.exists():
        return {
            "content": DEFAULT_SCRIPT_CONTENT,
            "error": None,
            "warning": "Soubor zatím neexistuje. Administrátor ho může vytvořit z výchozího obsahu.",
        }
    if not path.is_file():
        return {"content": "", "error": "Cesta není soubor.", "warning": None}
    try:
        if path.stat().st_size > MAX_SCRIPT_BYTES:
            return {"content": "", "error": "Soubor je větší než 100 KB.", "warning": None}
        content = path.read_text(encoding="utf-8")
    except Exception:
        return {"content": "", "error": "Soubor se nepodařilo načíst.", "warning": None}

    warning = None
    if not content.startswith("#!/usr/bin/env bash"):
        warning = "První řádek by měl být #!/usr/bin/env bash."
    return {"content": content, "error": None, "warning": warning}


def normalize_script_content(content: str) -> str:
    value = content.replace("\r\n", "\n").replace("\r", "\n")
    if not value.strip():
        raise HTTPException(status_code=400, detail="Obsah skriptu nesmí být prázdný")
    if len(value.encode("utf-8")) > MAX_SCRIPT_BYTES:
        raise HTTPException(status_code=400, detail="Obsah skriptu je větší než 100 KB")
    if not value.startswith("#!/usr/bin/env bash"):
        value = "#!/usr/bin/env bash\n" + value.lstrip("\n")
    if len(value.encode("utf-8")) > MAX_SCRIPT_BYTES:
        raise HTTPException(status_code=400, detail="Obsah skriptu je větší než 100 KB")
    return value


def save_script_file(script_name: str, content: str) -> None:
    path = script_path(script_name)
    value = normalize_script_content(content)
    try:
        path.parent.mkdir(parents=True, exist_ok=True)
        path.write_text(value, encoding="utf-8", newline="\n")
        os.chmod(path, 0o755)
    except Exception:
        raise HTTPException(status_code=500, detail="Soubor se nepodařilo uložit")


def form_metadata(
    name: str,
    description: str,
    event_type: str,
    service_id: str,
    script_name: str,
    is_enabled: str | None,
) -> dict:
    name_value = clean_optional(name)
    if not name_value:
        raise HTTPException(status_code=400, detail="Název je povinný")
    return {
        "name": name_value,
        "description": clean_optional(description),
        "event_type": validate_event_type(event_type),
        "service_id": clean_optional(service_id),
        "script_name": validate_script_name(script_name),
        "is_enabled": bool(is_enabled),
    }


def render_rule_form(rule: dict | None, action: str) -> str:
    rule = rule or {}
    name = html.escape(rule.get("name", "") or "")
    description = html.escape(rule.get("description", "") or "")
    service_id = html.escape(rule.get("service_id", "") or "")
    script_name = html.escape(rule.get("script_name", "log-alert.sh") or "log-alert.sh")
    event_type = rule.get("event_type", EVENT_TYPES[0]) or EVENT_TYPES[0]
    enabled_checked = " checked" if rule.get("is_enabled", True) else ""

    return f"""
        <form method="post" action="{action}" class="metadata-form">
            <label>Název</label>
            <input name="name" value="{name}" required>

            <label>Popis</label>
            <textarea name="description" rows="3">{description}</textarea>

            <label>Typ události</label>
            <select name="event_type">{render_event_type_options(event_type)}</select>

            <label>Služba</label>
            <input name="service_id" value="{service_id}" placeholder="volitelné ID služby">

            <label>Skript</label>
            <input name="script_name" value="{script_name}" placeholder="log-alert.sh" required>

            <label class="checkbox-label"><input type="checkbox" name="is_enabled" value="1"{enabled_checked}> Zapnuto</label>

            <div class="form-actions">
                <button type="submit">Uložit</button>
            </div>
        </form>
    """


def render_event_rows(events: list[dict], empty_colspan: int = 9, include_rule: bool = True) -> str:
    rows = ""
    for event in events:
        event_id = html.escape(str(event.get("id", "")))
        rule_id = event.get("rule_id")
        rule = ""
        if include_rule:
            if rule_id:
                rule_name = html.escape(event.get("rule_name") or f"#{rule_id}")
                rule = f'<td><a href="/portal/alerting/rules/{html.escape(str(rule_id))}">{rule_name}</a></td>'
            else:
                rule = "<td></td>"
        job_id = event.get("job_id")
        job_link = ""
        if job_id:
            job_id_html = html.escape(str(job_id))
            job_link = f'<a href="/portal/jobs/{job_id_html}">#{job_id_html}</a>'

        rows += f"""
        <tr>
            <td><strong><a href="/portal/alerting/events/{event_id}">#{event_id}</a></strong></td>
            {rule}
            <td>{html.escape(event.get("event_type", "") or "")}</td>
            <td>{html.escape(event.get("service_id", "") or "")}</td>
            <td>{html.escape(str(event.get("incident_id") or ""))}</td>
            <td>{render_status(event.get("status"))}</td>
            <td>{job_link}</td>
            <td>{html.escape(event.get("created_at", "") or "")}</td>
            <td><a class="btn" href="/portal/alerting/events/{event_id}">Detail</a></td>
        </tr>
        """

    if not rows:
        rows = f'<tr><td colspan="{empty_colspan}">Zatím nejsou evidované žádné alert eventy.</td></tr>'
    return rows


def render_script_editor(rule: dict, user: dict) -> str:
    script_name = rule.get("script_name", "") or ""
    script_name_html = html.escape(script_name)
    try:
        script_file = read_script_file(script_name)
    except HTTPException:
        script_file = {"content": "", "error": "Název skriptu není bezpečný.", "warning": None}

    content = html.escape(script_file.get("content", "") or "")
    warning = f'<p class="alert">{html.escape(script_file["warning"])}</p>' if script_file.get("warning") else ""
    error = f'<p class="alert alert-danger">{html.escape(script_file["error"])}</p>' if script_file.get("error") else ""

    if not is_admin(user):
        return f"""
        <div class="card">
            <h2>Obsah alert skriptu</h2>
            <p><strong>Soubor:</strong> {script_name_html}</p>
            {warning}
            {error}
            <p class="muted">Obsah skriptu je pouze pro čtení. Ukládat ho může jen administrátor.</p>
            <textarea rows="18" readonly>{content}</textarea>
        </div>
        """

    return f"""
        <div class="card">
            <h2>Editor alert skriptu</h2>
            <p><strong>Soubor:</strong> {script_name_html}</p>
            {warning}
            {error}
            <form method="post" action="/portal/alerting/rules/{html.escape(str(rule.get("id")))}/script" class="metadata-form">
                <label>Obsah souboru</label>
                <textarea name="content" rows="22" spellcheck="false">{content}</textarea>
                <div class="form-actions">
                    <button type="submit">Uložit skript</button>
                </div>
            </form>
        </div>
    """


@router.get("/alerting", response_class=HTMLResponse)
def alerting_redirect(user=Depends(require_user)):
    return RedirectResponse(url="/portal/alerting/rules", status_code=303)


@router.get("/alerting/rules", response_class=HTMLResponse)
def alert_rules_page(request: Request, user=Depends(require_user)):
    rows = ""
    for rule in get_alert_rules():
        rule_id = html.escape(str(rule.get("id", "")))
        enabled = bool(rule.get("is_enabled"))
        toggle_label = "Zakázat" if enabled else "Povolit"
        last_event = ""
        if rule.get("last_event_id"):
            event_id = html.escape(str(rule.get("last_event_id")))
            last_event = f'<a href="/portal/alerting/events/{event_id}">#{event_id}</a> {render_status(rule.get("last_event_status"))}'

        rows += f"""
        <tr>
            <td><strong><a href="/portal/alerting/rules/{rule_id}">{html.escape(rule.get("name", "") or "")}</a></strong></td>
            <td>{html.escape(rule.get("event_type", "") or "")}</td>
            <td>{html.escape(rule.get("service_id", "") or "")}</td>
            <td>{html.escape(rule.get("script_name", "") or "")}</td>
            <td>{render_enabled_pill(enabled)}</td>
            <td>{last_event}</td>
            <td>{html.escape(rule.get("updated_at", "") or "")}</td>
            <td class="actions-cell service-actions">
                <a class="btn" href="/portal/alerting/rules/{rule_id}">Detail</a>
                <a class="btn btn-secondary" href="/portal/alerting/rules/{rule_id}/edit">Upravit</a>
                <form method="post" action="/portal/alerting/rules/{rule_id}/toggle" class="inline-form">
                    <button type="submit" class="btn btn-secondary">{toggle_label}</button>
                </form>
                <form method="post" action="/portal/alerting/rules/{rule_id}/delete" class="inline-form" onsubmit="return confirm('Smazat alert pravidlo?');">
                    <button type="submit" class="danger">Smazat</button>
                </form>
            </td>
        </tr>
        """

    if not rows:
        rows = '<tr><td colspan="8">Zatím nejsou evidovaná žádná alert pravidla.</td></tr>'

    return page(
        "Alert pravidla",
        f"""
        <div class="card">
            <h2>Alert pravidla</h2>
            <p class="muted">Správa pravidel pro spouštění alert skriptů při událostech incidentů.</p>
            <p>
                <a class="btn" href="/portal/alerting/rules/new">+ Nové alert pravidlo</a>
                <a class="btn btn-secondary" href="/portal/alerting/events">Alert eventy</a>
            </p>
        </div>

        <div class="card">
            <h2>Pravidla</h2>
            <table>
                <tr>
                    <th>Název</th>
                    <th>Typ události</th>
                    <th>Služba</th>
                    <th>Skript</th>
                    <th>Stav</th>
                    <th>Poslední event</th>
                    <th>Upraveno</th>
                    <th>Akce</th>
                </tr>
                {rows}
            </table>
        </div>
        """,
        user=user,
    )


@router.get("/alerting/rules/new", response_class=HTMLResponse)
def new_alert_rule_form(request: Request, user=Depends(require_user)):
    return page(
        "Nové alert pravidlo",
        f"""
        <div class="card">
            <h2>Nové alert pravidlo</h2>
            <p><a class="btn" href="/portal/alerting/rules">&larr; Zpět</a></p>
        </div>
        <div class="card">
            {render_rule_form({"is_enabled": True, "event_type": EVENT_TYPES[0], "script_name": "log-alert.sh"}, "/portal/alerting/rules/new")}
        </div>
        """,
        user=user,
    )


@router.post("/alerting/rules/new")
def create_alert_rule_action(
    name: str = Form(...),
    description: str = Form(""),
    event_type: str = Form(...),
    service_id: str = Form(""),
    script_name: str = Form(...),
    is_enabled: str | None = Form(None),
    user=Depends(require_user),
):
    metadata = form_metadata(name, description, event_type, service_id, script_name, is_enabled)
    rule_id = create_alert_rule(metadata)
    log_audit_event(
        user,
        action="alert_rule.created",
        target_type="alert_rule",
        target_id=rule_id,
        metadata={"event_type": metadata["event_type"], "script_name": metadata["script_name"]},
    )
    return RedirectResponse(url=f"/portal/alerting/rules/{rule_id}", status_code=303)


@router.get("/alerting/rules/{rule_id}", response_class=HTMLResponse)
def alert_rule_detail(rule_id: int, request: Request, user=Depends(require_user)):
    rule = get_alert_rule(rule_id)
    if not rule:
        raise HTTPException(status_code=404, detail="Alert pravidlo nenalezeno")

    enabled = bool(rule.get("is_enabled"))
    toggle_label = "Zakázat" if enabled else "Povolit"
    events = get_rule_alert_events(rule_id, limit=20)

    return page(
        rule.get("name", "") or "Alert pravidlo",
        f"""
        <div class="card">
            <h2>{html.escape(rule.get("name", "") or "")}</h2>
            <p>
                <a class="btn" href="/portal/alerting/rules">&larr; Zpět na alert pravidla</a>
                <a class="btn btn-secondary" href="/portal/alerting/rules/{rule_id}/edit">Upravit</a>
                <a class="btn btn-secondary" href="/portal/alerting/events">Alert eventy</a>
            </p>
            <div class="inline-form">
                <form method="post" action="/portal/alerting/rules/{rule_id}/toggle">
                    <button type="submit" class="btn-secondary">{toggle_label}</button>
                </form>
                <form method="post" action="/portal/alerting/rules/{rule_id}/delete" onsubmit="return confirm('Smazat alert pravidlo?');">
                    <button type="submit" class="danger">Smazat</button>
                </form>
            </div>
        </div>

        <div class="card">
            <h2>Souhrn</h2>
            <table>
                <tr><th>Název</th><td>{html.escape(rule.get("name", "") or "")}</td></tr>
                <tr><th>Popis</th><td>{html.escape(rule.get("description", "") or "")}</td></tr>
                <tr><th>Typ události</th><td>{html.escape(rule.get("event_type", "") or "")}</td></tr>
                <tr><th>Služba</th><td>{html.escape(rule.get("service_id", "") or "")}</td></tr>
                <tr><th>Skript</th><td>{html.escape(rule.get("script_name", "") or "")}</td></tr>
                <tr><th>Zapnuto</th><td>{"Ano" if enabled else "Ne"}</td></tr>
                <tr><th>Vytvořeno</th><td>{html.escape(rule.get("created_at", "") or "")}</td></tr>
                <tr><th>Upraveno</th><td>{html.escape(rule.get("updated_at", "") or "")}</td></tr>
            </table>
        </div>

        <div class="card">
            <h2>Poslední eventy</h2>
            <table>
                <tr>
                    <th>ID</th>
                    <th>Typ události</th>
                    <th>Služba</th>
                    <th>Incident</th>
                    <th>Stav</th>
                    <th>Úloha</th>
                    <th>Vytvořeno</th>
                    <th>Akce</th>
                </tr>
                {render_event_rows(events, empty_colspan=8, include_rule=False)}
            </table>
        </div>

        {render_script_editor(rule, user)}
        """,
        user=user,
    )


@router.get("/alerting/rules/{rule_id}/edit", response_class=HTMLResponse)
def edit_alert_rule_form(rule_id: int, request: Request, user=Depends(require_user)):
    rule = get_alert_rule(rule_id)
    if not rule:
        raise HTTPException(status_code=404, detail="Alert pravidlo nenalezeno")
    return page(
        "Upravit alert pravidlo",
        f"""
        <div class="card">
            <h2>Upravit alert pravidlo</h2>
            <p><a class="btn" href="/portal/alerting/rules/{rule_id}">&larr; Zpět</a></p>
        </div>
        <div class="card">
            {render_rule_form(rule, f"/portal/alerting/rules/{rule_id}/edit")}
        </div>
        """,
        user=user,
    )


@router.post("/alerting/rules/{rule_id}/edit")
def update_alert_rule_action(
    rule_id: int,
    name: str = Form(...),
    description: str = Form(""),
    event_type: str = Form(...),
    service_id: str = Form(""),
    script_name: str = Form(...),
    is_enabled: str | None = Form(None),
    user=Depends(require_user),
):
    rule = get_alert_rule(rule_id)
    if not rule:
        raise HTTPException(status_code=404, detail="Alert pravidlo nenalezeno")
    metadata = form_metadata(name, description, event_type, service_id, script_name, is_enabled)
    update_alert_rule(rule_id, metadata)
    log_audit_event(
        user,
        action="alert_rule.updated",
        target_type="alert_rule",
        target_id=rule_id,
        metadata={"event_type": metadata["event_type"], "script_name": metadata["script_name"]},
    )
    return RedirectResponse(url=f"/portal/alerting/rules/{rule_id}", status_code=303)


@router.post("/alerting/rules/{rule_id}/toggle")
def toggle_alert_rule(rule_id: int, user=Depends(require_user)):
    rule = get_alert_rule(rule_id)
    if not rule:
        raise HTTPException(status_code=404, detail="Alert pravidlo nenalezeno")
    enabled = not bool(rule.get("is_enabled"))
    set_alert_rule_enabled(rule_id, enabled)
    log_audit_event(
        user,
        action="alert_rule.enabled" if enabled else "alert_rule.disabled",
        target_type="alert_rule",
        target_id=rule_id,
        metadata={"script_name": rule.get("script_name")},
    )
    return RedirectResponse(url=f"/portal/alerting/rules/{rule_id}", status_code=303)


@router.post("/alerting/rules/{rule_id}/delete")
def delete_alert_rule_action(rule_id: int, user=Depends(require_user)):
    rule = get_alert_rule(rule_id)
    if not rule:
        raise HTTPException(status_code=404, detail="Alert pravidlo nenalezeno")
    if not delete_alert_rule(rule_id):
        raise HTTPException(status_code=409, detail="Alert pravidlo nelze smazat")
    log_audit_event(
        user,
        action="alert_rule.deleted",
        target_type="alert_rule",
        target_id=rule_id,
        metadata={"script_name": rule.get("script_name")},
    )
    return RedirectResponse(url="/portal/alerting/rules", status_code=303)


@router.post("/alerting/rules/{rule_id}/script")
def update_alert_script(rule_id: int, content: str = Form(...), user=Depends(require_user)):
    if not is_admin(user):
        raise HTTPException(status_code=403, detail="Alert skript může upravit pouze administrátor")
    rule = get_alert_rule(rule_id)
    if not rule:
        raise HTTPException(status_code=404, detail="Alert pravidlo nenalezeno")
    script_name = validate_script_name(rule.get("script_name", "") or "")
    save_script_file(script_name, content)
    log_audit_event(
        user,
        action="alert_script.updated",
        target_type="alert_script",
        target_id=script_name,
        metadata={"alert_rule_id": rule_id, "script_name": script_name},
    )
    return RedirectResponse(url=f"/portal/alerting/rules/{rule_id}", status_code=303)


@router.get("/alerting/events", response_class=HTMLResponse)
def alert_events_page(request: Request, user=Depends(require_user)):
    events = get_alert_events(limit=200)
    return page(
        "Alert eventy",
        f"""
        <div class="card">
            <h2>Alert eventy</h2>
            <p class="muted">Historie vyvolaných alertů a jejich zpracování.</p>
            <p><a class="btn" href="/portal/alerting/rules">Alert pravidla</a></p>
        </div>

        <div class="card">
            <h2>Eventy</h2>
            <table>
                <tr>
                    <th>ID</th>
                    <th>Pravidlo</th>
                    <th>Typ události</th>
                    <th>Služba</th>
                    <th>Incident</th>
                    <th>Stav</th>
                    <th>Úloha</th>
                    <th>Vytvořeno</th>
                    <th>Akce</th>
                </tr>
                {render_event_rows(events)}
            </table>
        </div>
        """,
        user=user,
    )


@router.get("/alerting/events/{event_id}", response_class=HTMLResponse)
def alert_event_detail(event_id: int, request: Request, user=Depends(require_user)):
    event = get_alert_event(event_id)
    if not event:
        raise HTTPException(status_code=404, detail="Alert event nenalezeno")

    rule_link = ""
    if event.get("rule_id"):
        rule_id = html.escape(str(event.get("rule_id")))
        rule_name = html.escape(event.get("rule_name") or f"#{rule_id}")
        rule_link = f'<a href="/portal/alerting/rules/{rule_id}">{rule_name}</a>'

    job_link = ""
    if event.get("job_id"):
        job_id = html.escape(str(event.get("job_id")))
        job_link = f'<a href="/portal/jobs/{job_id}">#{job_id}</a>'

    error_text = html.escape(event.get("error_text", "") or "")
    payload = html.escape(pretty_json(event.get("payload_json")))

    return page(
        f"Alert event #{event_id}",
        f"""
        <div class="card">
            <h2>Alert event #{html.escape(str(event_id))}</h2>
            <p>
                <a class="btn" href="/portal/alerting/events">&larr; Zpět na alert eventy</a>
                <a class="btn btn-secondary" href="/portal/alerting/rules">Alert pravidla</a>
            </p>
        </div>

        <div class="card">
            <h2>Souhrn</h2>
            <table>
                <tr><th>Pravidlo</th><td>{rule_link}</td></tr>
                <tr><th>Typ události</th><td>{html.escape(event.get("event_type", "") or "")}</td></tr>
                <tr><th>Služba</th><td>{html.escape(event.get("service_id", "") or "")}</td></tr>
                <tr><th>Incident</th><td>{html.escape(str(event.get("incident_id") or ""))}</td></tr>
                <tr><th>Stav</th><td>{render_status(event.get("status"))}</td></tr>
                <tr><th>Úloha</th><td>{job_link}</td></tr>
                <tr><th>Vytvořeno</th><td>{html.escape(event.get("created_at", "") or "")}</td></tr>
                <tr><th>Zpracováno</th><td>{html.escape(event.get("processed_at", "") or "")}</td></tr>
            </table>
        </div>

        <div class="grid">
            <div class="card">
                <h2>Payload JSON</h2>
                <pre class="log-viewer log-stdout">{payload}</pre>
            </div>
            <div class="card">
                <h2>Chyba</h2>
                <pre class="log-viewer log-stderr">{error_text}</pre>
            </div>
        </div>
        """,
        user=user,
    )