from __future__ import annotations

from collections.abc import Iterable, Mapping

from sqlalchemy import and_, or_

from govoplan_core.core.access import AccessDecisionProvenance, PrincipalRef
from govoplan_core.core.campaigns import (
    CampaignAccessProvider,
    CampaignDeliveryTaskProvider,
    CampaignMailPolicyContext,
    CampaignMailPolicyContextProvider,
    CampaignPolicyContext,
    CampaignPolicyContextProvider,
    CampaignRetentionProvider,
)
from govoplan_core.security.module_permissions import scopes_grant_compatible

from govoplan_campaign.backend.db.models import Campaign, CampaignShare


READ_ACTIONS = {"campaigns:campaign:read", "campaign:read"}


class CampaignMailPolicyContextService(CampaignMailPolicyContextProvider):
    def get_campaign_mail_policy_context(
        self,
        session: object,
        *,
        tenant_id: str,
        campaign_id: str,
    ) -> CampaignMailPolicyContext | None:
        campaign = session.get(Campaign, campaign_id)  # type: ignore[attr-defined]
        if campaign is None or campaign.tenant_id != tenant_id:
            return None
        return CampaignMailPolicyContext(
            id=campaign.id,
            tenant_id=campaign.tenant_id,
            owner_user_id=campaign.owner_user_id,
            owner_group_id=campaign.owner_group_id,
            mail_profile_policy=dict(campaign.mail_profile_policy or {}),
        )

    def set_campaign_mail_profile_policy(
        self,
        session: object,
        *,
        tenant_id: str,
        campaign_id: str,
        policy: Mapping[str, object],
    ) -> Mapping[str, object]:
        campaign = session.get(Campaign, campaign_id)  # type: ignore[attr-defined]
        if campaign is None or campaign.tenant_id != tenant_id:
            raise ValueError("Campaign policy not found")
        payload = dict(policy)
        campaign.mail_profile_policy = payload
        session.add(campaign)  # type: ignore[attr-defined]
        return payload


def mail_policy_context_capability(context: object) -> CampaignMailPolicyContextService:
    return CampaignMailPolicyContextService()


class CampaignAccessService(CampaignAccessProvider):
    def campaign_exists(self, session: object, *, tenant_id: str, campaign_id: str) -> bool:
        campaign = session.get(Campaign, campaign_id)  # type: ignore[attr-defined]
        return bool(campaign and campaign.tenant_id == tenant_id)

    def can_read_campaign(
        self,
        session: object,
        *,
        tenant_id: str,
        campaign_id: str,
        user_id: str,
        group_ids: Iterable[str] = (),
        tenant_admin: bool = False,
    ) -> bool:
        campaign = session.get(Campaign, campaign_id)  # type: ignore[attr-defined]
        if campaign is None or campaign.tenant_id != tenant_id:
            return False
        if tenant_admin or campaign.owner_user_id == user_id:
            return True
        group_id_set = {str(group_id) for group_id in group_ids}
        if campaign.owner_group_id and campaign.owner_group_id in group_id_set:
            return True
        share_clauses = [
            and_(
                CampaignShare.target_type == "user",
                CampaignShare.target_id == user_id,
            )
        ]
        if group_id_set:
            share_clauses.append(
                and_(
                    CampaignShare.target_type == "group",
                    CampaignShare.target_id.in_(group_id_set),
                )
            )
        share = (
            session.query(CampaignShare)  # type: ignore[attr-defined]
            .filter(
                CampaignShare.tenant_id == tenant_id,
                CampaignShare.campaign_id == campaign.id,
                CampaignShare.revoked_at.is_(None),
                or_(*share_clauses),
            )
            .first()
        )
        return share is not None

    def explain_resource_provenance(
        self,
        session: object,
        principal: PrincipalRef,
        *,
        resource_type: str,
        resource_id: str,
        action: str,
    ) -> tuple[AccessDecisionProvenance, ...]:
        normalized_type = resource_type.lower().strip()
        if normalized_type not in {"campaign", "campaign_object", "campaigns:campaign"}:
            return ()
        campaign = session.get(Campaign, resource_id)  # type: ignore[attr-defined]
        if campaign is None or (principal.tenant_id and campaign.tenant_id != principal.tenant_id):
            return (
                AccessDecisionProvenance(
                    kind="resource",
                    id=resource_id,
                    tenant_id=principal.tenant_id,
                    source="campaigns.not_found",
                    details={"resource_type": "campaign", "found": False},
                ),
            )
        items = [
            AccessDecisionProvenance(
                kind="resource",
                id=campaign.id,
                label=campaign.name,
                tenant_id=campaign.tenant_id,
                source="campaigns.campaign",
                details={
                    "resource_type": "campaign",
                    "external_id": campaign.external_id,
                    "status": campaign.status,
                },
            )
        ]
        items.extend(_owner_provenance(campaign, principal))
        items.extend(_tenant_admin_provenance(principal))
        permission_values = {"read", "write"} if action in READ_ACTIONS else {"write"}
        shares = (
            session.query(CampaignShare)  # type: ignore[attr-defined]
            .filter(
                CampaignShare.tenant_id == campaign.tenant_id,
                CampaignShare.campaign_id == campaign.id,
                CampaignShare.revoked_at.is_(None),
                CampaignShare.permission.in_(sorted(permission_values)),
                or_(
                    (CampaignShare.target_type == "user") & (CampaignShare.target_id == principal.membership_id),
                    (CampaignShare.target_type == "group") & (CampaignShare.target_id.in_(sorted(principal.group_ids))),
                ),
            )
            .order_by(CampaignShare.target_type.asc(), CampaignShare.target_id.asc())
            .all()
        )
        for share in shares:
            items.append(
                AccessDecisionProvenance(
                    kind="share",
                    id=share.id,
                    label=share.permission,
                    tenant_id=share.tenant_id,
                    source="campaigns.share",
                    details={
                        "target_type": share.target_type,
                        "target_id": share.target_id,
                        "permission": share.permission,
                    },
                )
            )
        return tuple(items)


def access_capability(context: object) -> CampaignAccessService:
    return CampaignAccessService()


def _owner_provenance(campaign: Campaign, principal: PrincipalRef) -> tuple[AccessDecisionProvenance, ...]:
    if campaign.owner_user_id and campaign.owner_user_id == principal.membership_id:
        return (
            AccessDecisionProvenance(
                kind="owner",
                id=campaign.owner_user_id,
                tenant_id=campaign.tenant_id,
                source="campaigns.owner",
                details={"owner_type": "user"},
            ),
        )
    if campaign.owner_group_id and campaign.owner_group_id in principal.group_ids:
        return (
            AccessDecisionProvenance(
                kind="owner",
                id=campaign.owner_group_id,
                tenant_id=campaign.tenant_id,
                source="campaigns.owner",
                details={"owner_type": "group"},
            ),
        )
    return ()


def _tenant_admin_provenance(principal: PrincipalRef) -> tuple[AccessDecisionProvenance, ...]:
    if not scopes_grant_compatible(principal.scopes, "tenant:*"):
        return ()
    return (
        AccessDecisionProvenance(
            kind="policy",
            id="tenant:*",
            label="tenant:*",
            tenant_id=principal.tenant_id,
            source="campaigns.tenant_admin",
            details={"grant": "tenant_admin"},
        ),
    )


class CampaignPolicyContextService(CampaignPolicyContextProvider):
    def get_campaign_policy_context(
        self,
        session: object,
        *,
        tenant_id: str | None = None,
        campaign_id: str,
    ) -> CampaignPolicyContext | None:
        campaign = session.get(Campaign, campaign_id)  # type: ignore[attr-defined]
        if campaign is None or (tenant_id is not None and campaign.tenant_id != tenant_id):
            return None
        return CampaignPolicyContext(
            id=campaign.id,
            tenant_id=campaign.tenant_id,
            owner_user_id=campaign.owner_user_id,
            owner_group_id=campaign.owner_group_id,
            settings=dict(campaign.settings or {}),
        )

    def set_campaign_settings(
        self,
        session: object,
        *,
        tenant_id: str,
        campaign_id: str,
        settings: Mapping[str, object],
    ) -> Mapping[str, object]:
        campaign = session.get(Campaign, campaign_id)  # type: ignore[attr-defined]
        if campaign is None or campaign.tenant_id != tenant_id:
            raise ValueError("Campaign privacy policy not found")
        payload = dict(settings)
        campaign.settings = payload
        session.add(campaign)  # type: ignore[attr-defined]
        return payload


def policy_context_capability(context: object) -> CampaignPolicyContextService:
    return CampaignPolicyContextService()


class CampaignDeliveryTaskService(CampaignDeliveryTaskProvider):
    def send_campaign_job(self, session: object, *, job_id: str, enqueue_imap_task: bool = True) -> Mapping[str, object]:
        from govoplan_campaign.backend.sending.jobs import send_campaign_job

        return send_campaign_job(session, job_id=job_id, enqueue_imap_task=enqueue_imap_task).as_dict()  # type: ignore[arg-type]

    def append_sent_for_job(self, session: object, *, job_id: str) -> Mapping[str, object]:
        from govoplan_campaign.backend.sending.jobs import append_sent_for_job

        return append_sent_for_job(session, job_id=job_id).as_dict()  # type: ignore[arg-type]


def delivery_tasks_capability(context: object) -> CampaignDeliveryTaskService:
    from govoplan_campaign.backend.runtime import configure_runtime

    configure_runtime(
        registry=getattr(context, "registry", None),
        settings=getattr(context, "settings", None),
    )
    return CampaignDeliveryTaskService()


class CampaignRetentionService(CampaignRetentionProvider):
    def apply_retention(self, session: object, *, dry_run, now, policy_for_campaign_id):
        from govoplan_campaign.backend.retention import apply_campaign_retention

        return apply_campaign_retention(session, dry_run=dry_run, now=now, policy_for_campaign_id=policy_for_campaign_id)  # type: ignore[arg-type]


def retention_capability(context: object) -> CampaignRetentionService:
    return CampaignRetentionService()