from __future__ import annotations

from pathlib import PurePosixPath

from sqlalchemy.orm import Session

from app.db.models import CampaignAttachmentUse, CampaignJob, FileAsset
from app.storage.common import utcnow
from app.storage.files import current_version_and_blob, list_assets_for_user


def _candidate_match_keys(raw_match: str) -> set[str]:
    cleaned = raw_match.replace("\\", "/").strip().strip("/")
    result = {cleaned}
    if cleaned:
        result.add(PurePosixPath(cleaned).name)
    return {item for item in result if item}


def record_campaign_attachment_uses_for_job(session: Session, job: CampaignJob, *, stage: str = "built") -> None:
    """Create best-effort immutable file-use records for matched managed files.

    Existing attachment resolution is still filesystem/path based. This bridge
    records uses when a resolved attachment match can be tied to a managed file
    by logical path or filename among files shared with the campaign.
    """

    attachments = job.resolved_attachments or []
    if not isinstance(attachments, list):
        return
    assets = list_assets_for_user(
        session,
        tenant_id=job.tenant_id,
        user_id="",
        campaign_id=job.campaign_id,
        is_admin=True,
    )
    by_key: dict[str, FileAsset] = {}
    for asset in assets:
        by_key[asset.display_path.strip("/")] = asset
        by_key[asset.filename] = asset
    for attachment in attachments:
        if not isinstance(attachment, dict):
            continue
        matches = attachment.get("matches") if isinstance(attachment.get("matches"), list) else []
        for raw in matches:
            if not isinstance(raw, str):
                continue
            asset = next((by_key[key] for key in _candidate_match_keys(raw) if key in by_key), None)
            if not asset:
                continue
            version, blob = current_version_and_blob(session, asset)
            exists = (
                session.query(CampaignAttachmentUse)
                .filter(
                    CampaignAttachmentUse.campaign_job_id == job.id,
                    CampaignAttachmentUse.file_version_id == version.id,
                    CampaignAttachmentUse.filename_used == asset.filename,
                    CampaignAttachmentUse.use_stage == stage,
                )
                .one_or_none()
            )
            if exists:
                continue
            session.add(
                CampaignAttachmentUse(
                    tenant_id=job.tenant_id,
                    campaign_id=job.campaign_id,
                    campaign_version_id=job.campaign_version_id,
                    campaign_job_id=job.id,
                    entry_index=job.entry_index,
                    entry_id=job.entry_id,
                    file_asset_id=asset.id,
                    file_version_id=version.id,
                    file_blob_id=blob.id,
                    filename_used=asset.filename,
                    checksum_sha256=blob.checksum_sha256,
                    size_bytes=blob.size_bytes,
                    content_type=blob.content_type,
                    use_stage=stage,
                )
            )


def mark_job_attachment_uses_sent(session: Session, job: CampaignJob) -> None:
    record_campaign_attachment_uses_for_job(session, job, stage="built")
    now = utcnow()
    uses = (
        session.query(CampaignAttachmentUse)
        .filter(
            CampaignAttachmentUse.tenant_id == job.tenant_id,
            CampaignAttachmentUse.campaign_job_id == job.id,
            CampaignAttachmentUse.use_stage == "built",
        )
        .all()
    )
    for use in uses:
        sent = (
            session.query(CampaignAttachmentUse)
            .filter(
                CampaignAttachmentUse.campaign_job_id == job.id,
                CampaignAttachmentUse.file_version_id == use.file_version_id,
                CampaignAttachmentUse.use_stage == "sent",
            )
            .one_or_none()
        )
        if sent:
            continue
        session.add(
            CampaignAttachmentUse(
                tenant_id=use.tenant_id,
                campaign_id=use.campaign_id,
                campaign_version_id=use.campaign_version_id,
                campaign_job_id=use.campaign_job_id,
                entry_index=use.entry_index,
                entry_id=use.entry_id,
                file_asset_id=use.file_asset_id,
                file_version_id=use.file_version_id,
                file_blob_id=use.file_blob_id,
                filename_used=use.filename_used,
                checksum_sha256=use.checksum_sha256,
                size_bytes=use.size_bytes,
                content_type=use.content_type,
                use_stage="sent",
                used_at=now,
            )
        )