# Copyright (c) 2025 Patrick Motsch
# All rights reserved.
"""
Document reference models for typed document references in workflows.
"""

import logging
from typing import Any, List, Optional
from pydantic import BaseModel, Field
from modules.shared.i18nRegistry import i18nModel

logger = logging.getLogger(__name__)


class DocumentReference(BaseModel):
    """Base class for document references"""
    pass


@i18nModel("Dokumentlisten-Referenz")
class DocumentListReference(DocumentReference):
    """Reference to a document list via message label"""
    messageId: Optional[str] = Field(
        None,
        description="Optional message ID for cross-round references",
        json_schema_extra={"label": "Nachrichten-ID"},
    )
    label: str = Field(
        description="Document list label",
        json_schema_extra={"label": "Bezeichnung"},
    )

    def to_string(self) -> str:
        """Convert to string format: docList:messageId:label or docList:label"""
        if self.messageId:
            return f"docList:{self.messageId}:{self.label}"
        return f"docList:{self.label}"


@i18nModel("Dokumentelement-Referenz")
class DocumentItemReference(DocumentReference):
    """Reference to a specific document item"""
    documentId: str = Field(
        description="Document ID",
        json_schema_extra={"label": "Dokument-ID"},
    )
    fileName: Optional[str] = Field(
        None,
        description="Optional file name",
        json_schema_extra={"label": "Dateiname"},
    )

    def to_string(self) -> str:
        """Convert to string format: docItem:documentId:fileName or docItem:documentId"""
        if self.fileName:
            return f"docItem:{self.documentId}:{self.fileName}"
        return f"docItem:{self.documentId}"


@i18nModel("Dokumentreferenz-Liste")
class DocumentReferenceList(BaseModel):
    """List of document references with conversion methods"""
    references: List[DocumentReference] = Field(
        default_factory=list,
        description="List of document references",
        json_schema_extra={"label": "Referenzen"},
    )

    def to_string_list(self) -> List[str]:
        """Convert all references to string list"""
        return [ref.to_string() for ref in self.references]

    @classmethod
    def from_string_list(cls, stringList: List[str]) -> "DocumentReferenceList":
        """Parse string list to typed references

        Supports formats:
        - docList:label
        - docList:messageId:label
        - docItem:documentId
        - docItem:documentId:fileName
        """
        references = []

        for refStr in stringList:
            if not refStr or not isinstance(refStr, str):
                continue

            refStr = refStr.strip()

            # Parse docList: references
            if refStr.startswith("docList:"):
                parts = refStr[8:].split(":", 1)  # Remove "docList:" prefix
                if len(parts) == 2:
                    # docList:messageId:label
                    messageId, label = parts
                    references.append(DocumentListReference(messageId=messageId, label=label))
                elif len(parts) == 1 and parts[0]:
                    # docList:label
                    references.append(DocumentListReference(label=parts[0]))

            # Parse docItem: references
            elif refStr.startswith("docItem:"):
                parts = refStr[8:].split(":", 1)  # Remove "docItem:" prefix
                if len(parts) == 2:
                    # docItem:documentId:fileName
                    documentId, fileName = parts
                    references.append(DocumentItemReference(documentId=documentId, fileName=fileName))
                elif len(parts) == 1 and parts[0]:
                    # docItem:documentId
                    references.append(DocumentItemReference(documentId=parts[0]))

            # Unknown format - skip or log warning
            else:
                # Try to parse as simple string (backward compatibility)
                # Assume it's a label if it doesn't match known patterns
                if refStr:
                    references.append(DocumentListReference(label=refStr))

        return cls(references=references)


def coerceDocumentReferenceList(value: Any) -> DocumentReferenceList:
    """Tolerant coercion of any agent/UI-supplied document list to
    :class:`DocumentReferenceList`.

    Accepts the canonical formats plus the dict-wrapper shapes that
    LLM tool-callers tend to generate when they see a
    ``type=DocumentList`` parameter:

    * ``None`` / ``""`` -> empty list
    * :class:`DocumentReferenceList` -> as-is
    * ``str`` -> single-element string list
    * ``list[str]`` -> :meth:`from_string_list`
    * ``list[dict]`` with ``id`` or ``documentId`` -> item references
    * ``{"documents": [...]}`` / ``{"references": [...]}`` ->
      recurse into the inner list (this is the shape LLMs love)
    * ``{"id": "..."}`` / ``{"documentId": "..."}`` -> single
      item reference
    * any unrecognised input -> empty list with a WARN log; never
      raises (the caller decides whether an empty list is fatal).
    """
    if value is None or value == "":
        return DocumentReferenceList(references=[])
    if isinstance(value, DocumentReferenceList):
        return value
    if isinstance(value, str):
        return DocumentReferenceList.from_string_list([value])

    if isinstance(value, dict):
        for innerKey in ("documents", "references", "items", "files"):
            if innerKey in value and isinstance(value[innerKey], list):
                return coerceDocumentReferenceList(value[innerKey])
        docId = value.get("documentId") or value.get("id")
        if docId:
            return DocumentReferenceList(references=[
                DocumentItemReference(
                    documentId=str(docId),
                    fileName=value.get("fileName") or value.get("name"),
                )
            ])
        logger.warning(
            f"coerceDocumentReferenceList: unsupported dict shape "
            f"(keys={list(value.keys())}); returning empty list."
        )
        return DocumentReferenceList(references=[])

    if isinstance(value, list):
        if not value:
            return DocumentReferenceList(references=[])
        first = value[0]
        if isinstance(first, str):
            return DocumentReferenceList.from_string_list(value)
        if isinstance(first, dict):
            references: List[DocumentReference] = []
            for item in value:
                if not isinstance(item, dict):
                    continue
                docId = item.get("documentId") or item.get("id")
                if docId:
                    references.append(DocumentItemReference(
                        documentId=str(docId),
                        fileName=item.get("fileName") or item.get("name"),
                    ))
                elif item.get("label"):
                    references.append(DocumentListReference(
                        label=str(item["label"]),
                        messageId=item.get("messageId"),
                    ))
            return DocumentReferenceList(references=references)
        # Mixed/object list (e.g. inline ActionDocument-like): caller
        # must pre-handle that case before calling this coercer.
        logger.warning(
            f"coerceDocumentReferenceList: list element type "
            f"{type(first).__name__} not recognised; returning empty list."
        )
        return DocumentReferenceList(references=[])

    logger.warning(
        f"coerceDocumentReferenceList: unsupported value type "
        f"{type(value).__name__}; returning empty list."
    )
    return DocumentReferenceList(references=[])