from pathlib import Path
from datetime import datetime, timezone
import hashlib
import hmac
import json
import os
import secrets
from uuid import uuid4

import psycopg
from psycopg.types.json import Jsonb

from fastapi import FastAPI, Header, Request
from pydantic import BaseModel
from fastapi.responses import FileResponse


LOG_PATH = Path("activation.log")
DATABASE_URL = os.environ.get("TUXFLOTTE_DATABASE_URL")
AGENT_POLL_INTERVAL_SECONDS = int(os.environ.get("TUXFLOTTE_AGENT_POLL_INTERVAL", "300"))
ANSIBLE_CONTENT_REPO = os.environ.get("TUXFLOTTE_ANSIBLE_CONTENT_REPO", "")
AGENT_REPORTABLE_EVENT_TYPES = {"applied", "apply_failed", "removed", "remove_failed"}
app = FastAPI(title="Provisioning Activation Server", version="0.1.0")


class ActivationRequest(BaseModel):
    activation_code: str
    device_fingerprint: str
    hostname: str | None = None
    machine_id: str | None = None
    client_version: str | None = None
    hardware: dict


class ResolveRequest(BaseModel):
    device_id: str


class AgentBootstrapRequest(BaseModel):
    device_id: str


class AgentCheckinRequest(BaseModel):
    device_id: str


class AgentReportEntry(BaseModel):
    merkmal: str
    event_type: str
    detail: dict | None = None


class AgentReportRequest(BaseModel):
    device_id: str
    results: list[AgentReportEntry]


def write_log(entry: dict) -> None:
    with LOG_PATH.open("a", encoding="utf-8") as f:
        f.write(json.dumps(entry, ensure_ascii=False) + "\n")

def get_database_connection():
    if not DATABASE_URL:
        raise RuntimeError("TUXFLOTTE_DATABASE_URL ist nicht gesetzt.")

    return psycopg.connect(DATABASE_URL)

def load_or_create_device(
    organization_id,
    device_fingerprint: str,
    hostname: str | None,
) -> tuple[dict, bool]:
    """
    Lädt ein bekanntes Gerät oder legt es neu an.

    Rückgabe:
        (device, created)
    """

    with get_database_connection() as conn:
        with conn.cursor() as cur:
            cur.execute(
                """
                SELECT
                    id,
                    organization_id,
                    device_fingerprint,
                    hostname,
                    created_at,
                    last_seen
                FROM devices
                WHERE device_fingerprint = %s
                """,
                (device_fingerprint,),
            )

            row = cur.fetchone()

            if row is not None:
                if str(row[1]) != str(organization_id):
                    raise RuntimeError(
                    "Das Gerät ist bereits einer anderen Organization zugeordnet."
                    )
                cur.execute(
                    """
                    UPDATE devices
                    SET
                        hostname = %s,
                        last_seen = CURRENT_TIMESTAMP
                    WHERE id = %s
                    RETURNING
                        id,
                        organization_id,
                        device_fingerprint,
                        hostname,
                        created_at,
                        last_seen
                    """,
                    (hostname, row[0]),
                )

                row = cur.fetchone()
                created = False
            else:
                device_id = uuid4()

                cur.execute(
                    """
                    INSERT INTO devices (
                        id,
                        organization_id,
                        device_fingerprint,
                        hostname
                    )
                    VALUES (%s, %s, %s, %s)
                    RETURNING
                        id,
                        organization_id,
                        device_fingerprint,
                        hostname,
                        created_at,
                        last_seen
                    """,
                    (
                        device_id,
                        organization_id,
                        device_fingerprint,
                        hostname,
                    ),
                )

                row = cur.fetchone()
                created = True

    device = {
        "id": str(row[0]),
        "organization_id": str(row[1]),
        "device_fingerprint": row[2],
        "hostname": row[3],
        "created_at": row[4].isoformat(),
        "last_seen": row[5].isoformat(),
    }

    return device, created

def store_hardware_snapshot(
    device_id: str,
    hardware: dict,
) -> str:
    snapshot_id = uuid4()

    identity = hardware.get("identity", {})
    system = hardware.get("system", {})
    mainboard = hardware.get("mainboard", {})
    firmware = hardware.get("firmware", {})
    security = hardware.get("security", {})
    cpu = system.get("cpu", {})

    with get_database_connection() as conn:
        with conn.cursor() as cur:
            cur.execute(
                """
                INSERT INTO hardware_snapshots (
                    id,
                    device_id,
                    architecture,
                    manufacturer,
                    product_name,
                    product_version,
                    system_uuid,
                    system_serial,
                    board_vendor,
                    board_name,
                    board_serial,
                    bios_vendor,
                    bios_version,
                    boot_mode,
                    secure_boot,
                    tpm_version,
                    cpu_model,
                    cpu_logical_count,
                    memory_bytes
                )
                VALUES (
                    %s, %s, %s, %s, %s,
                    %s, %s, %s, %s, %s,
                    %s, %s, %s, %s, %s,
                    %s, %s, %s, %s
                )
                """,
                (
                    snapshot_id,
                    device_id,
                    system["architecture"],
                    system.get("manufacturer"),
                    system.get("product_name"),
                    system.get("product_version"),
                    identity.get("system_uuid"),
                    identity.get("system_serial"),
                    mainboard.get("vendor"),
                    mainboard.get("name"),
                    identity.get("board_serial"),
                    firmware.get("bios_vendor"),
                    firmware.get("bios_version"),
                    firmware.get("boot_mode"),
                    firmware.get("secure_boot"),
                    security.get("tpm_version"),
                    cpu.get("model"),
                    cpu.get("logical_count"),
                    system.get("memory_bytes"),
                ),
            )

            for interface in hardware.get("network_interfaces", []):
                cur.execute(
                    """
                    INSERT INTO network_interfaces (
                        id,
                        hardware_snapshot_id,
                        name,
                        type,
                        mac_address
                    )
                    VALUES (%s, %s, %s, %s, %s)
                    """,
                    (
                        uuid4(),
                        snapshot_id,
                        interface["name"],
                        interface["type"],
                        interface["mac"],
                    ),
                )

            for storage_device in hardware.get("storage_devices", []):
                cur.execute(
                    """
                    INSERT INTO storage_devices (
                        id,
                        hardware_snapshot_id,
                        name,
                        model,
                        serial,
                        size_bytes,
                        transport
                    )
                    VALUES (%s, %s, %s, %s, %s, %s, %s)
                    """,
                    (
                        uuid4(),
                        snapshot_id,
                        storage_device["name"],
                        storage_device.get("model"),
                        storage_device.get("serial"),
                        storage_device["size_bytes"],
                        storage_device.get("transport"),
                    ),
                )

    return str(snapshot_id)

def find_activation_code(code: str):
    with get_database_connection() as conn:
        with conn.cursor() as cur:
            cur.execute(
                """
                SELECT ac.organization_id, o.name
                FROM activation_codes ac
                JOIN organizations o ON o.id = ac.organization_id
                WHERE ac.code = %s AND ac.active
                """,
                (code,),
            )
            row = cur.fetchone()

    if row is None:
        return None

    return {"organization_id": str(row[0]), "organization_name": row[1]}

def fetch_templates(organization_id: str) -> list[dict]:
    with get_database_connection() as conn:
        with conn.cursor() as cur:
            cur.execute(
                """
                SELECT
                    bv.id, bv.label, bv.is_default,
                    w.id, w.name,
                    b.id, b.name, b.version
                FROM bereitstellungsvorlagen bv
                JOIN workspaces w ON w.id = bv.workspace_id
                JOIN backends b ON b.id = bv.backend_id
                WHERE bv.organization_id = %s
                ORDER BY bv.is_default DESC, bv.label
                """,
                (organization_id,),
            )
            rows = cur.fetchall()

    return [
        {
            "id": str(row[0]),
            "label": row[1],
            "workspace": {"id": str(row[3]), "name": row[4]},
            "backend": {"id": str(row[5]), "name": row[6], "version": row[7]},
            "is_default": row[2],
        }
        for row in rows
    ]

def hash_agent_secret(secret: str) -> str:
    return hashlib.sha256(secret.encode("utf-8")).hexdigest()

def verify_agent_secret(device_id: str, provided_secret: str) -> bool:
    with get_database_connection() as conn:
        with conn.cursor() as cur:
            cur.execute(
                "SELECT agent_secret_hash FROM devices WHERE id = %s",
                (device_id,),
            )
            row = cur.fetchone()

    if row is None or row[0] is None:
        return False

    return hmac.compare_digest(row[0], hash_agent_secret(provided_secret))

def fetch_assigned_blueprints(device_id: str):
    with get_database_connection() as conn:
        with conn.cursor() as cur:
            cur.execute(
                """
                SELECT bv.workspace_id, bv.backend_id
                FROM assignments a
                JOIN bereitstellungsvorlagen bv ON bv.id = a.bereitstellungsvorlage_id
                WHERE a.device_id = %s
                """,
                (device_id,),
            )
            assignment_row = cur.fetchone()

            if assignment_row is None:
                return []

            workspace_id, backend_id = assignment_row

            cur.execute(
                """
                SELECT m.key, bp.ansible_role
                FROM workspace_merkmale wm
                JOIN merkmale m ON m.id = wm.merkmal_id
                JOIN blueprints bp ON bp.merkmal_id = m.id AND bp.backend_id = %s
                WHERE wm.workspace_id = %s
                """,
                (backend_id, workspace_id),
            )
            return [
                {"merkmal": key, "ansible_role": ansible_role}
                for key, ansible_role in cur.fetchall()
            ]

def fetch_auftragskatalog_state(device_id: str):
    """
    Voller Soll-Zustand (present/absent) aller katalogfähigen Merkmale für
    das Backend des Device, unabhängig von der Workspace-Zuweisung
    (siehe ADR-0010). Zustandslos aus der aktuellen Auswahl abgeleitet,
    keine Historie nötig.
    """

    with get_database_connection() as conn:
        with conn.cursor() as cur:
            cur.execute(
                """
                SELECT bv.backend_id
                FROM assignments a
                JOIN bereitstellungsvorlagen bv ON bv.id = a.bereitstellungsvorlage_id
                WHERE a.device_id = %s
                """,
                (device_id,),
            )
            assignment_row = cur.fetchone()

            if assignment_row is None:
                return []

            (backend_id,) = assignment_row

            cur.execute(
                """
                SELECT m.key, bp.ansible_role, COALESCE(dm.aktiv, FALSE)
                FROM merkmale m
                JOIN blueprints bp ON bp.merkmal_id = m.id AND bp.backend_id = %s
                LEFT JOIN device_merkmale dm
                    ON dm.merkmal_id = m.id AND dm.device_id = %s
                WHERE m.im_auftragskatalog
                """,
                (backend_id, device_id),
            )
            return [
                {
                    "merkmal": key,
                    "ansible_role": ansible_role,
                    "state": "present" if aktiv else "absent",
                }
                for key, ansible_role, aktiv in cur.fetchall()
            ]

@app.get("/health")
def health():
    return {
        "status": "ok",
        "service": "provisioning-server",
        "version": "0.1.0"
    }


@app.post("/api/v1/activate")
def activate(payload: ActivationRequest, request: Request):
    activation = find_activation_code(payload.activation_code)

    success = activation is not None
    device = None
    device_created = False

    hardware_snapshot_id = None

    if success:
        organization_id = activation["organization_id"]

        device, device_created = load_or_create_device(
            organization_id,
            payload.device_fingerprint,
            payload.hostname,
        )
        hardware_snapshot_id = store_hardware_snapshot(
            device["id"],
            payload.hardware,
        )

    write_log({
        "timestamp": datetime.now(timezone.utc).isoformat(),
        "event": "activate",
        "success": success,
        "remote_ip": request.client.host if request.client else None,
        "activation_code": payload.activation_code,
        "hostname": payload.hostname,
        "machine_id": payload.machine_id,
        "client_version": payload.client_version
    })

    if not success:
        return {
            "success": False,
            "error": "invalid_activation_code",
            "message": "Der Aktivierungscode ist ungültig."
        }

    return {
        "success": True,

        "device": {
            "id": device["id"],
            "fingerprint": device["device_fingerprint"],
            "hostname": device["hostname"],
            "registration_status": (
                "registered"
                if device_created
                else "existing"
            ),
            "hardware_snapshot_id": hardware_snapshot_id,
        },

        "customer": {
            "id": activation["organization_id"],
            "organization_id": activation["organization_id"],
            "name": activation["organization_name"],
        },
        "templates": fetch_templates(activation["organization_id"]),
    }


@app.post("/api/v1/templates/{template_id}/resolve")
def resolve_template(template_id: str, payload: ResolveRequest):
    with get_database_connection() as conn:
        with conn.cursor() as cur:
            cur.execute(
                """
                SELECT bv.workspace_id, bv.backend_id, w.key, b.key,
                       bv.disk_encryption, bv.partitioning, bv.secure_boot_required
                FROM bereitstellungsvorlagen bv
                JOIN workspaces w ON w.id = bv.workspace_id
                JOIN backends b ON b.id = bv.backend_id
                WHERE bv.id = %s
                """,
                (template_id,),
            )
            template_row = cur.fetchone()

            if template_row is None:
                return {
                    "success": False,
                    "error": "template_not_found",
                    "message": "Die angeforderte Bereitstellungsvorlage wurde nicht gefunden."
                }

            (
                workspace_id, backend_id, workspace_key, backend_key,
                disk_encryption, partitioning, secure_boot_required,
            ) = template_row

            cur.execute(
                """
                SELECT m.key, bp.ansible_role
                FROM workspace_merkmale wm
                JOIN merkmale m ON m.id = wm.merkmal_id
                JOIN blueprints bp ON bp.merkmal_id = m.id AND bp.backend_id = %s
                WHERE wm.workspace_id = %s
                """,
                (backend_id, workspace_id),
            )
            blueprints = [
                {"merkmal": key, "ansible_role": ansible_role}
                for key, ansible_role in cur.fetchall()
            ]

            cur.execute(
                """
                INSERT INTO assignments (id, device_id, bereitstellungsvorlage_id)
                VALUES (%s, %s, %s)
                ON CONFLICT (device_id) DO UPDATE
                    SET bereitstellungsvorlage_id = EXCLUDED.bereitstellungsvorlage_id
                """,
                (uuid4(), payload.device_id, template_id),
            )

    return {
        "success": True,
        "runtime_blueprint": {
            "workspace_id": workspace_key,
            "backend_id": backend_key,
            "blueprints": blueprints,
            "installation_directives": {
                "disk_encryption": disk_encryption,
                "partitioning": partitioning,
                "secure_boot_required": secure_boot_required,
            },
        },
    }

@app.get("/installers/fedora-workstation/ks.cfg")
def get_fedora_kickstart():
    return FileResponse(
        "installers/fedora-workstation/ks.cfg",
        media_type="text/plain"
    )


@app.post("/api/v1/agent/bootstrap")
def agent_bootstrap(payload: AgentBootstrapRequest):
    agent_secret = secrets.token_urlsafe(32)

    with get_database_connection() as conn:
        with conn.cursor() as cur:
            cur.execute(
                """
                UPDATE devices
                SET agent_secret_hash = %s, agent_secret_issued_at = %s
                WHERE id = %s
                RETURNING id
                """,
                (
                    hash_agent_secret(agent_secret),
                    datetime.now(timezone.utc),
                    payload.device_id,
                ),
            )
            updated = cur.fetchone()

    if updated is None:
        return {
            "success": False,
            "error": "device_not_found",
            "message": "Das angegebene Gerät wurde nicht gefunden.",
        }

    return {"success": True, "agent_secret": agent_secret}


@app.post("/api/v1/agent/checkin")
def agent_checkin(
    payload: AgentCheckinRequest,
    authorization: str | None = Header(default=None),
):
    if authorization is None or not authorization.startswith("Bearer "):
        return {
            "success": False,
            "error": "unauthorized",
            "message": "Fehlendes oder ungültiges Authorization-Header.",
        }

    provided_secret = authorization.removeprefix("Bearer ")

    if not verify_agent_secret(payload.device_id, provided_secret):
        return {
            "success": False,
            "error": "unauthorized",
            "message": "Ungültiges Agent-Secret.",
        }

    with get_database_connection() as conn:
        with conn.cursor() as cur:
            cur.execute(
                "UPDATE devices SET agent_last_checkin = %s WHERE id = %s",
                (datetime.now(timezone.utc), payload.device_id),
            )

    return {
        "success": True,
        "blueprints": fetch_assigned_blueprints(payload.device_id),
        "auftraege": fetch_auftragskatalog_state(payload.device_id),
        "ansible_repo": ANSIBLE_CONTENT_REPO,
        "poll_interval_seconds": AGENT_POLL_INTERVAL_SECONDS,
    }


@app.post("/api/v1/agent/report")
def agent_report(
    payload: AgentReportRequest,
    authorization: str | None = Header(default=None),
):
    if authorization is None or not authorization.startswith("Bearer "):
        return {
            "success": False,
            "error": "unauthorized",
            "message": "Fehlendes oder ungültiges Authorization-Header.",
        }

    provided_secret = authorization.removeprefix("Bearer ")

    if not verify_agent_secret(payload.device_id, provided_secret):
        return {
            "success": False,
            "error": "unauthorized",
            "message": "Ungültiges Agent-Secret.",
        }

    for entry in payload.results:
        if entry.event_type not in AGENT_REPORTABLE_EVENT_TYPES:
            return {
                "success": False,
                "error": "invalid_event_type",
                "message": f"Kein vom Agenten meldbarer event_type: {entry.event_type}",
            }

    with get_database_connection() as conn:
        with conn.cursor() as cur:
            merkmal_ids = {}

            for entry in payload.results:
                if entry.merkmal in merkmal_ids:
                    continue

                cur.execute(
                    "SELECT id FROM merkmale WHERE key = %s",
                    (entry.merkmal,),
                )
                merkmal_row = cur.fetchone()

                if merkmal_row is None:
                    return {
                        "success": False,
                        "error": "unknown_merkmal",
                        "message": f"Unbekanntes Merkmal: {entry.merkmal}",
                    }

                merkmal_ids[entry.merkmal] = merkmal_row[0]

            for entry in payload.results:
                cur.execute(
                    """
                    INSERT INTO device_merkmal_events (
                        id, device_id, merkmal_id, event_type, detail
                    )
                    VALUES (%s, %s, %s, %s, %s)
                    """,
                    (
                        uuid4(),
                        payload.device_id,
                        merkmal_ids[entry.merkmal],
                        entry.event_type,
                        Jsonb(entry.detail) if entry.detail is not None else None,
                    ),
                )

    return {"success": True}