"""System-level endpoints (admin only).

Provides manual triggers for background operations such as the MITRE
ATT&CK synchronisation, intel scanning, Atomic Red Team import, and
scheduler health introspection.

Also exposes email configuration CRUD (admin only) that writes to the
system_configs table so settings survive container restarts.
"""

import logging
from typing import Optional

from fastapi import APIRouter, BackgroundTasks, Depends, HTTPException, Request, status
from pydantic import BaseModel
from sqlalchemy.orm import Session

from app.database import SessionLocal, get_db
from app.dependencies.auth import require_role
from app.models.user import User
from app.services.mitre_sync_service import sync_mitre
from app.services.intel_service import scan_intel
from app.services.atomic_import_service import import_atomic_red_team
from app.jobs.mitre_sync_job import scheduler
from app.limiter import limiter

logger = logging.getLogger(__name__)

router = APIRouter(prefix="/system", tags=["system"])


# ---------------------------------------------------------------------------
# Pydantic schemas for email config
# ---------------------------------------------------------------------------


class EmailConfigOut(BaseModel):
    enabled: bool
    host: str
    port: int
    username: str
    from_email: str
    use_tls: bool
    # password is never returned


class EmailConfigUpdate(BaseModel):
    enabled: Optional[bool] = None
    host: Optional[str] = None
    port: Optional[int] = None
    username: Optional[str] = None
    password: Optional[str] = None
    from_email: Optional[str] = None
    use_tls: Optional[bool] = None


class EmailTestRequest(BaseModel):
    to: str


# ---------------------------------------------------------------------------
# Helpers for system_configs CRUD
# ---------------------------------------------------------------------------

_SMTP_KEYS = {
    "enabled": "smtp.enabled",
    "host": "smtp.host",
    "port": "smtp.port",
    "username": "smtp.username",
    "password": "smtp.password",
    "from_email": "smtp.from_email",
    "use_tls": "smtp.use_tls",
}


def _upsert_config(db: Session, key: str, value: str) -> None:
    from app.models.system_config import SystemConfig  # lazy import avoids circular

    row = db.query(SystemConfig).filter(SystemConfig.key == key).first()
    if row:
        row.value = value
    else:
        row = SystemConfig(key=key, value=value)
        db.add(row)


def _read_email_config_from_db(db: Session) -> dict:
    """Return a dict with resolved email settings (DB overrides env)."""
    from app.services.email_service import _get_smtp_config

    return _get_smtp_config(db)


def _bg_mitre_sync() -> None:
    """Run MITRE sync in a background task with its own DB session."""
    logger.info("Background MITRE sync task starting...")
    db = SessionLocal()
    try:
        summary = sync_mitre(db)
        logger.info("Background MITRE sync task finished — %s", summary)
    except Exception:
        logger.exception("Background MITRE sync task failed")
    finally:
        db.close()


@router.post("/sync-mitre")
@limiter.limit("2/hour")
def trigger_mitre_sync(
    request: Request,
    background_tasks: BackgroundTasks,
    current_user: User = Depends(require_role("admin")),
):
    """Manually trigger a MITRE ATT&CK synchronisation in the background.

    **Requires** the ``admin`` role.

    Returns immediately — the sync runs asynchronously. Poll
    ``/system/scheduler-status`` for progress, or check server logs.
    """
    background_tasks.add_task(_bg_mitre_sync)
    return {
        "message": "MITRE sync started in background",
        "status": "started",
        "new": 0,
        "updated": 0,
    }


@router.post("/run-intel-scan")
def trigger_intel_scan(
    db: Session = Depends(get_db),
    current_user: User = Depends(require_role("admin")),
):
    """Manually trigger a threat-intelligence scan.

    **Requires** the ``admin`` role.

    Returns a JSON object with the scan summary including the count of
    new intel items found.
    """
    summary = scan_intel(db)
    return {
        "message": "Intel scan completed",
        "new_items": summary["new_items"],
    }


@router.post("/import-atomic-tests")
@limiter.limit("2/hour")
def trigger_atomic_import(
    request: Request,
    db: Session = Depends(get_db),
    current_user: User = Depends(require_role("admin")),
):
    """Trigger an import of Atomic Red Team tests as TestTemplates.

    **Requires** the ``admin`` role.

    Downloads the Atomic Red Team repository ZIP from GitHub, parses the
    YAML files, and creates/updates TestTemplate records.  Running this
    endpoint multiple times is idempotent — duplicates are skipped.

    Returns a JSON object with import statistics.
    """
    try:
        summary = import_atomic_red_team(db)
    except Exception as exc:
        logger.error("Atomic Red Team import failed: %s", exc, exc_info=True)
        return {
            "message": "Import failed. Check server logs for details.",
        }

    return {
        "message": "Import completed",
        "imported": summary["created"],
        "skipped": summary["skipped_existing"],
        "total_parsed": summary["total_tests_parsed"],
    }


@router.get("/scheduler-status")
def scheduler_status(
    current_user: User = Depends(require_role("admin")),
):
    """Return the current state of the background scheduler.

    **Requires** the ``admin`` role.
    """
    jobs = scheduler.get_jobs()
    return {
        "running": scheduler.running,
        "jobs": [
            {
                "id": job.id,
                "name": job.name,
                "next_run_time": str(job.next_run_time) if job.next_run_time else None,
            }
            for job in jobs
        ],
    }


# ---------------------------------------------------------------------------
# Jira config endpoints (admin only)
# ---------------------------------------------------------------------------


class JiraConfigOut(BaseModel):
    enabled: bool
    url: str
    project_key: str
    parent_ticket: str
    # Credentials are never returned


class JiraConfigUpdate(BaseModel):
    enabled: Optional[bool] = None
    url: Optional[str] = None
    project_key: Optional[str] = None
    parent_ticket: Optional[str] = None


_JIRA_KEYS = {
    "enabled": "jira.enabled",
    "url": "jira.url",
    "project_key": "jira.project_key",
    "parent_ticket": "jira.parent_ticket",
}


@router.get("/jira-config", response_model=JiraConfigOut)
def get_jira_config(
    db: Session = Depends(get_db),
    current_user: User = Depends(require_role("admin")),
):
    """Return current Jira configuration (merged DB + env).

    **Requires** the ``admin`` role. Credentials are never returned.
    """
    from app.services.jira_service import get_jira_url, get_jira_project_key, is_jira_enabled, get_jira_parent_ticket

    return JiraConfigOut(
        enabled=is_jira_enabled(db),
        url=get_jira_url(db) or "",
        project_key=get_jira_project_key(db) or "",
        parent_ticket=get_jira_parent_ticket(db) or "",
    )


@router.patch("/jira-config", response_model=JiraConfigOut)
def update_jira_config(
    payload: JiraConfigUpdate,
    db: Session = Depends(get_db),
    current_user: User = Depends(require_role("admin")),
):
    """Update Jira configuration and persist to DB.

    **Requires** the ``admin`` role. Only provided fields are updated.
    """
    from app.services.jira_service import (
        upsert_jira_config, get_jira_url, get_jira_project_key, is_jira_enabled, get_jira_parent_ticket,
    )

    update_data = payload.model_dump(exclude_unset=True)
    for field, val in update_data.items():
        db_key = _JIRA_KEYS.get(field)
        if db_key:
            upsert_jira_config(db, db_key, str(val))
    db.commit()

    return JiraConfigOut(
        enabled=is_jira_enabled(db),
        url=get_jira_url(db) or "",
        project_key=get_jira_project_key(db) or "",
        parent_ticket=get_jira_parent_ticket(db) or "",
    )


@router.post("/jira-test")
def test_jira_connection(
    db: Session = Depends(get_db),
    current_user: User = Depends(require_role("admin")),
):
    """Test the Jira connection using the current user's credentials.

    Requires the admin to have a personal Jira API token configured in their
    profile settings.
    """
    from app.services.jira_service import get_user_jira_client, get_jira_url

    jira_url = get_jira_url(db)
    if not jira_url:
        raise HTTPException(status_code=400, detail="Jira URL not configured.")

    try:
        jira = get_user_jira_client(current_user, db)
        # Lightweight call: get current user info (10 s hard timeout)
        jira._session.timeout = 10  # type: ignore[attr-defined]
        myself = jira.myself()
        return {
            "status": "ok",
            "connected_as": myself.get("displayName") or myself.get("emailAddress", "unknown"),
            "jira_url": jira_url,
        }
    except Exception as exc:
        err = str(exc)
        # Translate common Atlassian-library errors into human-readable messages
        if "Expecting value" in err or "line 1 column 1" in err:
            detail = (
                "Jira returned an unexpected response — check that the URL is correct "
                "and that the account email + API token are valid."
            )
        elif "401" in err or "Unauthorized" in err:
            detail = "Authentication failed (401). Verify your Atlassian email and API token."
        elif "403" in err or "Forbidden" in err:
            detail = "Access denied (403). The token may not have permission to access this Jira instance."
        elif "timed out" in err.lower() or "timeout" in err.lower():
            detail = "Connection timed out. Check the Jira URL is reachable from the server."
        else:
            detail = f"Jira connection failed: {err}"
        raise HTTPException(status_code=502, detail=detail)


# ---------------------------------------------------------------------------
# GET /system/email-config
# ---------------------------------------------------------------------------


@router.get("/email-config", response_model=EmailConfigOut)
def get_email_config(
    db: Session = Depends(get_db),
    current_user: User = Depends(require_role("admin")),
):
    """Return current SMTP email configuration (merged DB + env).

    **Requires** the ``admin`` role. Password is never returned.
    """
    cfg = _read_email_config_from_db(db)
    return EmailConfigOut(
        enabled=cfg["enabled"],
        host=cfg["host"],
        port=cfg["port"],
        username=cfg["username"],
        from_email=cfg["from_email"],
        use_tls=cfg["use_tls"],
    )


# ---------------------------------------------------------------------------
# PATCH /system/email-config
# ---------------------------------------------------------------------------


@router.patch("/email-config", response_model=EmailConfigOut)
def update_email_config(
    payload: EmailConfigUpdate,
    db: Session = Depends(get_db),
    current_user: User = Depends(require_role("admin")),
):
    """Update SMTP email configuration and persist to DB.

    **Requires** the ``admin`` role.
    Only provided fields are updated (partial update).
    """
    update_data = payload.model_dump(exclude_unset=True)
    for field, val in update_data.items():
        db_key = _SMTP_KEYS.get(field)
        if db_key:
            _upsert_config(db, db_key, str(val))
    db.commit()

    cfg = _read_email_config_from_db(db)
    return EmailConfigOut(
        enabled=cfg["enabled"],
        host=cfg["host"],
        port=cfg["port"],
        username=cfg["username"],
        from_email=cfg["from_email"],
        use_tls=cfg["use_tls"],
    )


# ---------------------------------------------------------------------------
# POST /system/email-test
# ---------------------------------------------------------------------------


@router.post("/email-test")
def send_test_email(
    payload: EmailTestRequest,
    db: Session = Depends(get_db),
    current_user: User = Depends(require_role("admin")),
):
    """Send a test email to verify SMTP configuration.

    **Requires** the ``admin`` role.
    Returns 200 on success, 502 if sending fails.
    """
    from app.services.email_service import send_test_email as _send_test

    ok = _send_test(payload.to, db=db)
    if not ok:
        raise HTTPException(
            status_code=status.HTTP_502_BAD_GATEWAY,
            detail="Failed to send test email. Check SMTP configuration and server logs.",
        )
    return {"detail": f"Test email sent to {payload.to}"}