from __future__ import annotations

from datetime import date, timedelta
from urllib.parse import urlencode

from fastapi import APIRouter, Form, Request
from fastapi.responses import RedirectResponse
from sqlalchemy import select

from app.core.db.common import CommonSessionLocal
from app.core.security.csrf import get_or_create_csrf_token, validate_csrf
from app.core.templating import templates
from app.modules.accounting.historical_learning_models import AccountingHistoricalLearningRun
from app.modules.accounting.ledger_learning_service import available_tally_guids
from app.modules.accounting.sales_learning_models import AccountingSalesHistoricalRun
from app.modules.accounting.sales_learning_service import (
    historical_sales_rows,
    ingest_completed_sales_run,
    learning_summary,
    sales_mappings,
)
from app.modules.accounting.ui import _find_visible_client, _require_partner, _visible_clients
from app.modules.core.rbac.deps import get_user_permissions, get_user_roles
from app.modules.documents.agent_jobs import enqueue_agent_job
from app.modules.documents.models import ERPWorkstationAgent

router = APIRouter(
    prefix="/tools/accounting/sales-learning",
    tags=["accounting-sales-learning-ui"],
)


def _go(client_id=0, message="", error=""):
    q = {}
    if client_id:
        q["client_id"] = client_id
    if message:
        q["message"] = message[:300]
    if error:
        q["error"] = error[:300]
    return RedirectResponse(
        "/tools/accounting/sales-learning" + ("?" + urlencode(q) if q else ""),
        status_code=303,
    )


def _workstations(db, tenant_id: int):
    return list(db.execute(
        select(ERPWorkstationAgent).where(
            ERPWorkstationAgent.tenant_id == int(tenant_id),
            ERPWorkstationAgent.is_active.is_(True),
            ERPWorkstationAgent.tally_connected.is_(True),
        ).order_by(ERPWorkstationAgent.machine_name)
    ).scalars().all())


@router.get("")
def page(
    request: Request,
    client_id: int | None = None,
    message: str = "",
    error: str = "",
):
    db = CommonSessionLocal()
    try:
        user, denied = _require_partner(request, db, "accounting.learning.view")
        if denied:
            return denied

        clients, scope = _visible_clients(db, request, user)
        selected = next(
            (row for row in clients if client_id and int(row.id) == int(client_id)),
            None,
        )

        mappings = []
        evidence = []
        summary = {"mapping_count": 0, "historical_rows": 0, "review_confirmed": 0, "high_confidence": 0}
        guids = []
        workstations = []
        runs = []

        if selected:
            # Synchronize latest sales evidence run states opportunistically.
            runs = list(db.execute(
                select(AccountingSalesHistoricalRun).where(
                    AccountingSalesHistoricalRun.tenant_id == scope.tenant_id,
                    AccountingSalesHistoricalRun.client_id == selected.id,
                ).order_by(AccountingSalesHistoricalRun.id.desc()).limit(20)
            ).scalars().all())
            for run in runs:
                if run.status not in {"completed", "failed"}:
                    ingest_completed_sales_run(db, run)

            mappings = sales_mappings(db, tenant_id=scope.tenant_id, client_id=selected.id)
            evidence = historical_sales_rows(db, tenant_id=scope.tenant_id, client_id=selected.id)[:200]
            summary = learning_summary(db, tenant_id=scope.tenant_id, client_id=selected.id)
            guids = available_tally_guids(db, scope.tenant_id, selected.id)
            workstations = _workstations(db, scope.tenant_id)

        return templates.TemplateResponse(
            "modules/accounting/templates/accounting/sales_learning.html",
            {
                "request": request,
                "current_user": user,
                "current_user_roles": get_user_roles(db, user.id),
                "current_user_permissions": get_user_permissions(db, user.id),
                "csrf_token": get_or_create_csrf_token(request),
                "title": "Customer & Sales Ledger Intelligence",
                "clients": clients,
                "selected_client": selected,
                "mappings": mappings,
                "evidence": evidence,
                "summary": summary,
                "tally_guids": guids,
                "workstations": workstations,
                "runs": runs,
                "message": message,
                "error": error,
            },
        )
    finally:
        db.close()


@router.post("/collect")
def collect(
    request: Request,
    client_id: int = Form(...),
    workstation_id: int = Form(...),
    tally_guid: str = Form(...),
    date_from: str = Form(""),
    date_to: str = Form(""),
    csrf_token: str = Form(...),
):
    validate_csrf(request, csrf_token)
    db = CommonSessionLocal()
    try:
        user, denied = _require_partner(request, db, "accounting.learning.manage")
        if denied:
            return denied

        client, _, scope = _find_visible_client(db, request, user, client_id)
        if not client:
            return _go(error="Client is not visible.")

        workstation = db.get(ERPWorkstationAgent, int(workstation_id))
        if (
            not workstation
            or int(workstation.tenant_id) != int(scope.tenant_id)
            or not workstation.is_active
            or not workstation.tally_connected
        ):
            raise ValueError("Selected workstation is not available with Tally connected.")

        guid_options = dict(available_tally_guids(db, scope.tenant_id, client.id))
        if tally_guid not in guid_options:
            raise ValueError("Selected Tally company is not mapped to this client.")

        if not date_from:
            date_from = (date.today() - timedelta(days=730)).isoformat()
        if not date_to:
            date_to = date.today().isoformat()

        payload = {
            "tenant_id": scope.tenant_id,
            "client_id": client.id,
            "tally_guid": tally_guid,
            "date_from": date_from,
            "date_to": date_to,
            "voucher_scope": "sales",
        }
        job = enqueue_agent_job(
            db,
            workstation_agent_id=workstation.id,
            action="accounting_historical_evidence",
            payload=payload,
            priority=6,
            max_attempts=2,
            created_by_user_id=user.id,
        )

        run = AccountingSalesHistoricalRun(
            tenant_id=scope.tenant_id,
            client_id=client.id,
            tally_guid=tally_guid,
            company_name=guid_options.get(tally_guid, ""),
            workstation_agent_id=workstation.id,
            agent_job_id=job.id,
            date_from=date_from,
            date_to=date_to,
            status="queued",
            requested_by_user_id=user.id,
        )
        db.add(run)
        db.commit()

        return _go(
            client.id,
            message="Historical Tally Sales evidence collection queued.",
        )
    except Exception as exc:
        db.rollback()
        return _go(client_id, error=str(exc))
    finally:
        db.close()