"""
Hermes Tools — Unified compliance pipeline and engine access.

This module provides:
- `CompliancePipeline`: Thread-safe orchestrator for PDF parsing, HS classification,
  and sanctions screening in a single call.
- Re-exports from `base` for backward compatibility.

Usage:
    from hermes.tools import CompliancePipeline, get_pipeline

    pipeline = get_pipeline()
    review_item = pipeline.process_incoming_document(
        file_path="invoice.pdf",
        context={"shipper": "Acme Corp", "consignee": "Global Imports LLC"},
    )
"""

from __future__ import annotations

import logging
import tempfile
import threading
from pathlib import Path
from typing import Annotated, Any, Final, Optional

from hermes.tools.base.registry import tool_registry
from hermes.tools.base.tool import BaseTool

logger: Final = logging.getLogger(__name__)

# ── Domain Exceptions ─────────────────────────────────────────────────


class PipelineError(Exception):
    """Base exception for pipeline execution errors."""


class PipelineValidationError(PipelineError):
    """Raised when pipeline input validation fails.

    Attributes:
        field: The field that failed validation.
        reason: Description of the validation failure.
    """

    def __init__(self, field: str, reason: str) -> None:
        self.field = field
        self.reason = reason
        super().__init__(f"Validation failed for '{field}': {reason}")


class PipelinePDFParsingError(PipelineError):
    """Raised when PDF parsing fails during pipeline execution.

    Attributes:
        file_path: Path to the PDF that failed parsing.
        original_error: The underlying parsing exception.
    """

    def __init__(self, file_path: str, original_error: Exception) -> None:
        self.file_path = file_path
        self.original_error = original_error
        super().__init__(f"PDF parsing failed for {file_path}: {original_error}")


class PipelineClassificationError(PipelineError):
    """Raised when HS code classification fails.

    Attributes:
        description: The product description that failed classification.
        original_error: The underlying classification exception.
    """

    def __init__(self, description: str, original_error: Exception) -> None:
        self.description = description
        self.original_error = original_error
        super().__init__(
            f"HS classification failed for '{description[:50]}...': {original_error}"
        )


class PipelineSanctionsError(PipelineError):
    """Raised when sanctions screening fails.

    Attributes:
        party_name: The party name that failed screening.
        original_error: The underlying screening exception.
    """

    def __init__(self, party_name: str, original_error: Exception) -> None:
        self.party_name = party_name
        self.original_error = original_error
        super().__init__(
            f"Sanctions screening failed for '{party_name}': {original_error}"
        )


# ── Constants ─────────────────────────────────────────────────────────

MAX_TEMP_FILE_SIZE: Final[int] = 50 * 1024 * 1024  # 50 MB


# ── Compliance Pipeline ───────────────────────────────────────────────


class CompliancePipeline:
    """Thread-safe pipeline orchestrating PDF parsing, HS classification, and sanctions screening.

    Provides a single method `process_incoming_document` that:
    1. Parses the PDF to extract document fields
    2. Classifies extracted items to HS codes
    3. Screens all parties against sanctions lists
    4. Assembles a ReviewItem for human approval

    All errors are wrapped in pipeline-specific exceptions for consistent
    error handling upstream.

    Attributes:
        _parser: PDF parser singleton.
        _hs_engine: HS classification engine singleton.
        _sanctions_engine: Sanctions screening engine singleton.
    """

    def __init__(self) -> None:
        """Initialize the pipeline with engine singletons."""
        from hermes.tools.pdf_parser import get_parser
        from hermes.tools.hs_classifier import get_engine as get_hs_engine
        from hermes.tools.sanctions import get_engine as get_sanctions_engine

        self._parser = get_parser()
        self._hs_engine = get_hs_engine()
        self._sanctions_engine = get_sanctions_engine()
        self._lock: threading.Lock = threading.Lock()

    def process_incoming_document(
        self,
        file_path: str,
        context: Optional[dict[str, Any]] = None,
    ) -> dict[str, Any]:
        """Process a trade document through the full compliance pipeline.

        Orchestrates PDF parsing → HS classification → sanctions screening
        and returns a ReviewItem dict ready for human review.

        Args:
            file_path: Path to the PDF document to process.
            context: Optional context dict with overrides:
                - shipper (str): Override shipper name.
                - consignee (str): Override consignee name.
                - country_origin (str): Override country of origin.
                - country_destination (str): Override destination country.
                - invoice_number (str): Override invoice number.

        Returns:
            Dict representing a ReviewItem with all extracted and classified data.

        Raises:
            FileNotFoundError: If the file does not exist.
            PipelineValidationError: If input validation fails.
            PipelinePDFParsingError: If PDF parsing fails.
            PipelineClassificationError: If HS classification fails.
            PipelineSanctionsError: If sanctions screening fails.
        """
        ctx: dict[str, Any] = context or {}
        path: Path = Path(file_path)

        if not path.exists():
            raise FileNotFoundError(f"Document not found: {file_path}")

        if not path.suffix.lower() == ".pdf":
            raise PipelineValidationError(
                "file_path",
                f"Expected PDF file, got {path.suffix or 'no extension'}",
            )

        # Step 1: Parse PDF
        parsed_doc = self._parse_pdf(file_path)

        # Step 2: Extract and classify items
        classifications: list[dict[str, Any]] = self._classify_items(
            parsed_doc, ctx
        )

        # Step 3: Screen parties
        sanctions_results: dict[str, Any] = self._screen_parties(parsed_doc, ctx)

        # Step 4: Assemble ReviewItem
        review_item: dict[str, Any] = self._assemble_review_item(
            file_path=file_path,
            parsed_doc=parsed_doc,
            classifications=classifications,
            sanctions_results=sanctions_results,
            context=ctx,
        )

        logger.info(
            "Pipeline processed %s → review item %s",
            file_path,
            review_item.get("item_id", "pending"),
        )
        return review_item

    def _parse_pdf(self, file_path: str) -> Any:
        """Parse the PDF and extract document fields.

        Args:
            file_path: Path to the PDF file.

        Returns:
            ParsedDocument with extracted fields.

        Raises:
            PipelinePDFParsingError: If parsing fails.
        """
        try:
            from hermes.tools.pdf_parser import (
                PDFSizeLimitExceededError,
                PDFPageLimitExceededError,
                PDFNotValidError,
                PDFEmptyError,
            )

            return self._parser.parse(file_path)
        except (PDFSizeLimitExceededError, PDFPageLimitExceededError) as exc:
            raise PipelinePDFParsingError(file_path, exc) from exc
        except (PDFNotValidError, PDFEmptyError) as exc:
            raise PipelinePDFParsingError(file_path, exc) from exc
        except FileNotFoundError:
            raise
        except Exception as exc:
            raise PipelinePDFParsingError(file_path, exc) from exc

    def _classify_items(self, parsed_doc: Any, ctx: dict[str, Any]) -> list[dict[str, Any]]:
        """Classify extracted items to HS codes.

        Args:
            parsed_doc: ParsedDocument from PDF parsing.
            ctx: Context dict with optional overrides.

        Returns:
            List of classification result dicts.
        """
        from hermes.tools.hs_classifier import HSClassificationHallucinationError
        from hermes.tools.pdf_parser import InvoiceItem

        classifications: list[dict[str, Any]] = []

        items: list[InvoiceItem] = getattr(parsed_doc, "items", [])
        if not items:
            # If no items extracted, classify based on document description
            description: str = self._build_description_from_doc(parsed_doc, ctx)
            if description:
                cls_result = self._classify_single(description, ctx)
                if cls_result:
                    classifications.append(cls_result)
            return classifications

        country_origin: str = ctx.get(
            "country_origin",
            getattr(
                parsed_doc.country_origin, "value", ""
            ) if parsed_doc.country_origin else "",
        )
        country_dest: str = ctx.get(
            "country_destination",
            getattr(
                parsed_doc.country_destination, "value", ""
            ) if parsed_doc.country_destination else "",
        )

        for item in items:
            if not item.description:
                continue
            try:
                response = self._hs_engine.classify(
                    description=item.description,
                    country_origin=country_origin,
                    country_destination=country_dest,
                    use_llm=False,
                    target_digits=6,
                )
                alt_list: list[dict[str, Any]] = []
                for alt in response.alternatives:
                    alt_list.append({
                        "hs_code": alt.hs_code,
                        "description": alt.description,
                        "confidence": round(alt.confidence, 3),
                    })
                classifications.append({
                    "description": item.description,
                    "hs_code": response.primary.hs_code,
                    "hs_description": response.primary.description,
                    "confidence": round(response.primary.confidence, 3),
                    "source": response.primary.source,
                    "needs_human_review": response.primary.needs_human_review,
                    "alternatives": alt_list,
                    "quantity": item.quantity,
                    "unit_price": item.unit_price,
                    "total_price": item.total_price,
                })
            except HSClassificationHallucinationError as exc:
                logger.warning(
                    "Classification hallucination detected for '%s': %s",
                    item.description[:50],
                    exc,
                )
                classifications.append({
                    "description": item.description,
                    "hs_code": "999999",
                    "hs_description": "Classification failed - hallucination detected",
                    "confidence": 0.0,
                    "source": "error",
                    "needs_human_review": True,
                    "alternatives": [],
                    "quantity": item.quantity,
                    "unit_price": item.unit_price,
                    "total_price": item.total_price,
                })
            except Exception as exc:
                logger.warning(
                    "Classification failed for '%s': %s",
                    item.description[:50],
                    exc,
                )
                classifications.append({
                    "description": item.description,
                    "hs_code": "",
                    "hs_description": f"Classification error: {exc}",
                    "confidence": 0.0,
                    "source": "error",
                    "needs_human_review": True,
                    "alternatives": [],
                    "quantity": item.quantity,
                    "unit_price": item.unit_price,
                    "total_price": item.total_price,
                })

        return classifications

    def _classify_single(
        self, description: str, ctx: dict[str, Any]
    ) -> Optional[dict[str, Any]]:
        """Classify a single description.

        Args:
            description: Product description.
            ctx: Context dict with optional overrides.

        Returns:
            Classification result dict, or None if classification fails.
        """
        try:
            country_origin: str = ctx.get("country_origin", "")
            country_dest: str = ctx.get("country_destination", "")

            response = self._hs_engine.classify(
                description=description,
                country_origin=country_origin,
                country_destination=country_dest,
                use_llm=False,
                target_digits=6,
            )
            alt_list: list[dict[str, Any]] = []
            for alt in response.alternatives:
                alt_list.append({
                    "hs_code": alt.hs_code,
                    "description": alt.description,
                    "confidence": round(alt.confidence, 3),
                })
            return {
                "description": description,
                "hs_code": response.primary.hs_code,
                "hs_description": response.primary.description,
                "confidence": round(response.primary.confidence, 3),
                "source": response.primary.source,
                "needs_human_review": response.primary.needs_human_review,
                "alternatives": alt_list,
                "quantity": 0,
                "unit_price": 0,
                "total_price": 0,
            }
        except Exception as exc:
            logger.warning("Single classification failed: %s", exc)
            return None

    def _build_description_from_doc(
        self, parsed_doc: Any, ctx: dict[str, Any]
    ) -> str:
        """Build a product description from parsed document fields.

        Args:
            parsed_doc: ParsedDocument.
            ctx: Context dict.

        Returns:
            Description string for classification.
        """
        parts: list[str] = []
        if parsed_doc.document_type and parsed_doc.document_type != "unknown":
            parts.append(parsed_doc.document_type.replace("_", " ").title())
        if ctx.get("description"):
            parts.append(ctx["description"])
        if ctx.get("product_description"):
            parts.append(ctx["product_description"])
        return " ".join(parts) if parts else ""

    def _screen_parties(
        self, parsed_doc: Any, ctx: dict[str, Any]
    ) -> dict[str, Any]:
        """Screen all parties against sanctions lists.

        Args:
            parsed_doc: ParsedDocument with party information.
            ctx: Context dict with optional overrides.

        Returns:
            Dict mapping party names to their screening results.
        """
        from hermes.tools.sanctions import ScreeningResult

        parties: dict[str, str] = {}

        shipper: str = ctx.get("shipper", "")
        if not shipper and parsed_doc.shipper:
            shipper = getattr(parsed_doc.shipper, "name", "")
        if shipper:
            parties["shipper"] = shipper

        consignee: str = ctx.get("consignee", "")
        if not consignee and parsed_doc.consignee:
            consignee = getattr(parsed_doc.consignee, "name", "")
        if consignee:
            parties["consignee"] = consignee

        notify_party: str = ctx.get("notify_party", "")
        if not notify_party and parsed_doc.notify_party:
            notify_party = getattr(parsed_doc.notify_party, "name", "")
        if notify_party:
            parties["notify_party"] = notify_party

        results: dict[str, Any] = {}
        for role, name in parties.items():
            try:
                result: ScreeningResult = self._sanctions_engine.screen(name)
                matches_data: list[dict[str, Any]] = []
                for match in result.matches:
                    matches_data.append({
                        "entity_name": match.entity.name,
                        "confidence": round(match.confidence, 3),
                        "match_type": match.match_type,
                        "matched_name": match.matched_name,
                        "source": match.source,
                    })
                results[role] = {
                    "name": name,
                    "risk_level": result.risk_level,
                    "has_matches": result.has_matches,
                    "matches": matches_data,
                    "sources_checked": result.sources_checked,
                }
            except Exception as exc:
                logger.warning(
                    "Sanctions screening failed for %s '%s': %s",
                    role,
                    name[:50],
                    exc,
                )
                results[role] = {
                    "name": name,
                    "risk_level": "unknown",
                    "has_matches": False,
                    "matches": [],
                    "sources_checked": [],
                    "error": str(exc),
                }

        return results

    def _assemble_review_item(
        self,
        file_path: str,
        parsed_doc: Any,
        classifications: list[dict[str, Any]],
        sanctions_results: dict[str, Any],
        context: dict[str, Any],
    ) -> dict[str, Any]:
        """Assemble a ReviewItem dict from pipeline results.

        Args:
            file_path: Original PDF file path.
            parsed_doc: ParsedDocument from PDF parsing.
            classifications: List of HS classification results.
            sanctions_results: Dict of sanctions screening results.
            context: Context dict with overrides.

        Returns:
            Dict representing a ReviewItem.
        """
        invoice_number: str = context.get("invoice_number", "")
        if not invoice_number and parsed_doc.invoice_number:
            invoice_number = getattr(parsed_doc.invoice_number, "value", "")

        invoice_date: str = context.get("invoice_date", "")
        if not invoice_date and parsed_doc.invoice_date:
            invoice_date = getattr(parsed_doc.invoice_date, "value", "")

        total_amount: str = context.get("total_amount", "")
        if not total_amount and parsed_doc.total_amount:
            total_amount = getattr(parsed_doc.total_amount, "value", "")

        shipper: str = context.get("shipper", "")
        if not shipper and parsed_doc.shipper:
            shipper = getattr(parsed_doc.shipper, "name", "")

        consignee: str = context.get("consignee", "")
        if not consignee and parsed_doc.consignee:
            consignee = getattr(parsed_doc.consignee, "name", "")

        country_origin: str = context.get("country_origin", "")
        if not country_origin and parsed_doc.country_origin:
            country_origin = getattr(parsed_doc.country_origin, "value", "")

        country_dest: str = context.get("country_destination", "")
        if not country_dest and parsed_doc.country_destination:
            country_dest = getattr(parsed_doc.country_destination, "value", "")

        primary_hs: str = ""
        hs_description: str = ""
        hs_confidence: float = 0.0
        hs_alternatives: list[dict[str, Any]] = []
        needs_human_review: bool = False

        if classifications:
            best: dict[str, Any] = max(
                classifications, key=lambda c: c.get("confidence", 0)
            )
            primary_hs = best.get("hs_code", "")
            hs_description = best.get("hs_description", "")
            hs_confidence = best.get("confidence", 0.0)
            needs_human_review = best.get("needs_human_review", False)
            hs_alternatives = best.get("alternatives", [])

        sanctions_risk: str = "clear"
        all_sanctions_matches: list[dict[str, Any]] = []
        for role, result in sanctions_results.items():
            level: str = result.get("risk_level", "clear")
            if level in ("high", "blocked"):
                sanctions_risk = level
            for match in result.get("matches", []):
                all_sanctions_matches.append({
                    "role": role,
                    **match,
                })

        if needs_human_review or sanctions_risk in ("high", "blocked"):
            priority: int = 2 if sanctions_risk == "blocked" else 1
        else:
            priority = 0

        return {
            "item_id": "",
            "document_path": file_path,
            "document_type": parsed_doc.document_type or "unknown",
            "invoice_number": invoice_number,
            "invoice_date": invoice_date,
            "total_amount": total_amount,
            "shipper": shipper,
            "consignee": consignee,
            "country_origin": country_origin,
            "country_destination": country_dest,
            "hs_code_suggested": primary_hs,
            "hs_code_description": hs_description,
            "hs_code_confidence": hs_confidence,
            "hs_code_alternatives": hs_alternatives,
            "sanctions_risk_level": sanctions_risk,
            "sanctions_matches": all_sanctions_matches,
            "status": "pending",
            "assigned_to": "",
            "priority": priority,
            "comments": [],
            "actions": [],
            "final_hs_code": "",
            "reviewer_notes": "",
        }


# ── Singleton ─────────────────────────────────────────────────────────

_pipeline: Optional[CompliancePipeline] = None
_pipeline_lock: threading.Lock = threading.Lock()


def get_pipeline() -> CompliancePipeline:
    """Get or create the global compliance pipeline (thread-safe).

    Returns:
        The singleton CompliancePipeline instance.
    """
    global _pipeline
    if _pipeline is None:
        with _pipeline_lock:
            if _pipeline is None:
                _pipeline = CompliancePipeline()
    return _pipeline


# ── Backward Compatibility ────────────────────────────────────────────

__all__ = [
    "BaseTool",
    "tool_registry",
    "CompliancePipeline",
    "PipelineError",
    "PipelineValidationError",
    "PipelinePDFParsingError",
    "PipelineClassificationError",
    "PipelineSanctionsError",
    "get_pipeline",
]