from __future__ import annotations

from datetime import datetime

from sqlalchemy import select
from sqlalchemy.orm import Session

from app.core.config import get_settings
from app.models.audit import AuditEvent
from app.models.booking import Booking
from app.models.data_quality import DataQualityIssue
from app.models.outbox import OutboxEvent
from app.schemas import DemoIntegrationSummaryOut, DemoManifestOut, DemoScenarioOut
from app.services.integration_status import derive_n8n_status
from app.services.knowledge import get_knowledge_provider

settings = get_settings()

# The default name matches the project's locked fictitious tenant (see PROJECT_STATE.md
# "Locked decisions"; the same slug already backs `ragcore_tenant`) — this surfaces that
# existing decision in the UI rather than inventing a new one. Configurable via
# DEMO_ORGANIZATION_NAME so a redeployment can rebrand the fictional org without a code change.
ORGANIZATION_DESCRIPTION = (
    "MobilityOps brengt voertuig-, boekings- en operationele gegevens samen, "
    "ondersteunt verhuurprocessen, detecteert datakwaliteitsproblemen en "
    "automatiseert gecontroleerde vervolgstappen."
)

_FAILED_DEMO_EVENT_ID = "00000000-0000-4000-8000-000000000020"

_N8N_STATE_LABELS = {
    "disabled": "Niet gekoppeld",
    "unavailable": "Verwerking mislukt",
    "degraded": "Opnieuw proberen mogelijk",
    "operational": "Operationeel",
    "no_evidence": "Voorbereid",
}


def _last_reset(db: Session) -> tuple[datetime | None, str | None]:
    marker = db.scalar(
        select(AuditEvent)
        .where(AuditEvent.action == "demo_data_seeded")
        .order_by(AuditEvent.occurred_at.desc())
    )
    if marker is None:
        return None, None
    metadata = marker.metadata_json or {}
    return marker.occurred_at, metadata.get("anchor_date")


def _scenarios(db: Session) -> list[DemoScenarioOut]:
    booking = db.scalar(select(Booking).where(Booking.public_ref == "BK-DEMO-RETURN"))
    duplicate_issue = db.scalar(
        select(DataQualityIssue).where(DataQualityIssue.public_ref == "DQ-DEMO-DUPLICATE")
    )
    overlap_issue = db.scalar(
        select(DataQualityIssue).where(DataQualityIssue.public_ref == "DQ-DEMO-OVERLAP")
    )
    failed_run = db.scalar(
        select(OutboxEvent).where(OutboxEvent.event_id == _FAILED_DEMO_EVENT_ID)
    )
    knowledge_health = get_knowledge_provider().health()
    reset_hint = "Reset de demo-data om dit scenario opnieuw beschikbaar te maken."

    return [
        DemoScenarioOut(
            id="return-anomaly",
            title="Retour met afwijkende kilometerstand",
            operational_problem=(
                "Een voertuig komt terug met een kilometerstand die lager ligt dan de "
                "laatst geregistreerde stand — een teken van een foutieve invoer of een "
                "verwisseld voertuig."
            ),
            estimated_minutes=3,
            required_roles=["rental_employee", "operations_manager"],
            start_path=f"/bookings/{booking.public_ref}" if booking else "/bookings",
            demonstrates=(
                "Retourverwerking, automatische detectie van datakwaliteitsproblemen en de "
                "audit trail die daaruit ontstaat."
            ),
            ready=bool(
                booking and booking.status == "active" and booking.end_odometer_km is None
            ),
            blocked_reason=(
                None
                if booking and booking.status == "active" and booking.end_odometer_km is None
                else (
                    f"Demoboeking BK-DEMO-RETURN niet gevonden. {reset_hint}"
                    if booking is None
                    else f"Deze boeking is al verwerkt sinds de laatste reset. {reset_hint}"
                )
            ),
        ),
        DemoScenarioOut(
            id="duplicate-customer",
            title="Mogelijke dubbele klant samenvoegen",
            operational_problem=(
                "Twee klantprofielen delen hetzelfde e-mailadres en telefoonnummer — "
                "waarschijnlijk dezelfde persoon, twee keer geregistreerd."
            ),
            estimated_minutes=3,
            required_roles=["operations_manager"],
            start_path=(
                f"/data-quality/{duplicate_issue.public_ref}"
                if duplicate_issue
                else "/data-quality"
            ),
            demonstrates=(
                "Samenvoegen van klanten met behoud van boekingsgeschiedenis en audit trail."
            ),
            ready=bool(duplicate_issue and duplicate_issue.status == "open"),
            blocked_reason=(
                None
                if duplicate_issue and duplicate_issue.status == "open"
                else (
                    f"Demo-issue DQ-DEMO-DUPLICATE niet gevonden. {reset_hint}"
                    if duplicate_issue is None
                    else f"Dit issue is al opgelost sinds de laatste reset. {reset_hint}"
                )
            ),
        ),
        DemoScenarioOut(
            id="booking-overlap",
            title="Overlappende boekingen herstellen",
            operational_problem=(
                "Eén voertuig staat dubbel gereserveerd voor overlappende periodes — een "
                "planningsfout die vóór vertrek moet worden opgelost."
            ),
            estimated_minutes=2,
            required_roles=["operations_manager"],
            start_path=(
                f"/data-quality/{overlap_issue.public_ref}" if overlap_issue else "/data-quality"
            ),
            demonstrates="Detectie en gecontroleerde oplossing van planningsconflicten.",
            ready=bool(overlap_issue and overlap_issue.status == "open"),
            blocked_reason=(
                None
                if overlap_issue and overlap_issue.status == "open"
                else (
                    f"Demo-issue DQ-DEMO-OVERLAP niet gevonden. {reset_hint}"
                    if overlap_issue is None
                    else f"Dit issue is al opgelost sinds de laatste reset. {reset_hint}"
                )
            ),
        ),
        DemoScenarioOut(
            id="automation-retry",
            title="Mislukte automatisering opnieuw proberen",
            operational_problem=(
                "Eén eerdere gebeurtenis kon niet worden afgeleverd aan de automatisering "
                "door een gesimuleerde verbindingsfout."
            ),
            estimated_minutes=2,
            required_roles=["operations_manager"],
            start_path="/automation",
            demonstrates=(
                "Betrouwbare aflevering met begrensde herpogingen en zichtbare foutstatus."
            ),
            ready=bool(failed_run and failed_run.delivery_status == "failed"),
            blocked_reason=(
                None
                if failed_run and failed_run.delivery_status == "failed"
                else (
                    f"Gesimuleerde mislukte gebeurtenis niet gevonden. {reset_hint}"
                    if failed_run is None
                    else f"Deze gebeurtenis is al hersteld sinds de laatste reset. {reset_hint}"
                )
            ),
        ),
        DemoScenarioOut(
            id="knowledge-question",
            title="Een procedurevraag stellen",
            operational_problem=(
                "Een medewerker weet niet zeker welke procedure van toepassing is bij een "
                "specifieke operationele situatie."
            ),
            estimated_minutes=2,
            required_roles=["rental_employee", "operations_manager"],
            start_path="/knowledge",
            demonstrates=(
                "Antwoorden met brongebaseerde onderbouwing uit een afgebakende demokennisbank."
            ),
            ready=knowledge_health.available,
            blocked_reason=(
                None
                if knowledge_health.available
                else "De demokennisbank is momenteel niet beschikbaar."
            ),
        ),
    ]


def _integrations(db: Session) -> list[DemoIntegrationSummaryOut]:
    n8n = derive_n8n_status(db)
    knowledge_health = get_knowledge_provider().health()

    return [
        DemoIntegrationSummaryOut(
            key="n8n",
            label="Automatisering (n8n)",
            status_label=_N8N_STATE_LABELS.get(n8n.state, n8n.state),
            detail=f"{n8n.succeeded} geslaagd, {n8n.failed} mislukt, {n8n.pending} in wachtrij.",
        ),
        DemoIntegrationSummaryOut(
            key="ragcore",
            label="Kennisassistent (RAGcore)",
            status_label=(
                "Demomodus — lokale kennisprovider"
                if knowledge_health.provider != "ragcore"
                else "Operationeel"
            ),
            detail=knowledge_health.detail,
        ),
        DemoIntegrationSummaryOut(
            key="mcp_hub",
            label="ITWorx MCP Hub",
            status_label=(
                "Operationeel" if settings.mcp_hub_registration_enabled else "Niet gekoppeld"
            ),
            detail="Voorbereid voor toekomstige, gecontroleerde tool-aanroepen vanuit de Hub.",
        ),
    ]


def build_demo_manifest(db: Session) -> DemoManifestOut:
    last_reset_at, anchor_date = _last_reset(db)
    return DemoManifestOut(
        demo_mode=settings.mobilityops_demo_mode,
        organization_name=settings.demo_organization_name,
        organization_description=ORGANIZATION_DESCRIPTION,
        timezone=settings.demo_timezone,
        synthetic_data=True,
        allow_reset=settings.demo_allow_reset,
        last_reset_at=last_reset_at,
        anchor_date=anchor_date,
        guide_available=True,
        required_roles=["operations_manager", "rental_employee"],
        scenarios=_scenarios(db),
        integrations=_integrations(db),
    )