"""
Document Intelligence Tools for Agents

Tool implementations for DocumentAgent integration.
Each tool is designed for ReAct-style agent execution.
"""

import json
import logging
from dataclasses import dataclass
from pathlib import Path
from typing import Any, Dict, List, Optional, Union

logger = logging.getLogger(__name__)


@dataclass
class ToolResult:
    """Result from a tool execution."""

    success: bool
    data: Any = None
    error: Optional[str] = None
    evidence: List[Dict[str, Any]] = None

    def __post_init__(self):
        if self.evidence is None:
            self.evidence = []

    def to_dict(self) -> Dict[str, Any]:
        return {
            "success": self.success,
            "data": self.data,
            "error": self.error,
            "evidence": self.evidence,
        }


class DocumentTool:
    """Base class for document tools."""

    name: str = "base_tool"
    description: str = "Base document tool"

    def execute(self, **kwargs) -> ToolResult:
        """Execute the tool."""
        raise NotImplementedError


class ParseDocumentTool(DocumentTool):
    """
    Parse a document into semantic chunks.

    Input:
        path: Path to document file
        max_pages: Optional maximum pages to process

    Output:
        ParseResult with chunks and metadata
    """

    name = "parse_document"
    description = "Parse a document into semantic chunks with OCR and layout detection"

    def __init__(self, parser=None):
        from ..parsing import DocumentParser
        self.parser = parser or DocumentParser()

    def execute(
        self,
        path: str,
        max_pages: Optional[int] = None,
        **kwargs
    ) -> ToolResult:
        try:
            # Update config if max_pages specified
            if max_pages:
                self.parser.config.max_pages = max_pages

            result = self.parser.parse(path)

            return ToolResult(
                success=True,
                data={
                    "doc_id": result.doc_id,
                    "filename": result.filename,
                    "num_pages": result.num_pages,
                    "num_chunks": len(result.chunks),
                    "chunks": [
                        {
                            "chunk_id": c.chunk_id,
                            "type": c.chunk_type.value,
                            "text": c.text[:500],  # Truncate for display
                            "page": c.page,
                            "confidence": c.confidence,
                        }
                        for c in result.chunks[:20]  # Limit for display
                    ],
                    "markdown_preview": result.markdown_full[:2000],
                },
            )
        except Exception as e:
            logger.error(f"Parse document failed: {e}")
            return ToolResult(success=False, error=str(e))


class ExtractFieldsTool(DocumentTool):
    """
    Extract fields from a parsed document using a schema.

    Input:
        parse_result: Previously parsed document
        schema: Extraction schema (dict or ExtractionSchema)
        fields: Optional list of specific fields to extract

    Output:
        ExtractionResult with values and evidence
    """

    name = "extract_fields"
    description = "Extract structured fields from document using a schema"

    def __init__(self, extractor=None):
        from ..extraction import FieldExtractor
        self.extractor = extractor or FieldExtractor()

    def execute(
        self,
        parse_result: Any,
        schema: Union[Dict, Any],
        fields: Optional[List[str]] = None,
        **kwargs
    ) -> ToolResult:
        try:
            from ..extraction import ExtractionSchema

            # Convert dict schema to ExtractionSchema
            if isinstance(schema, dict):
                schema = ExtractionSchema.from_json_schema(schema)

            # Filter fields if specified
            if fields:
                schema.fields = [f for f in schema.fields if f.name in fields]

            result = self.extractor.extract(parse_result, schema)

            return ToolResult(
                success=True,
                data={
                    "extracted_data": result.data,
                    "confidence": result.overall_confidence,
                    "abstained_fields": result.abstained_fields,
                },
                evidence=[
                    {
                        "chunk_id": e.chunk_id,
                        "page": e.page,
                        "bbox": e.bbox.xyxy,
                        "snippet": e.snippet,
                        "confidence": e.confidence,
                    }
                    for e in result.evidence
                ],
            )
        except Exception as e:
            logger.error(f"Extract fields failed: {e}")
            return ToolResult(success=False, error=str(e))


class SearchChunksTool(DocumentTool):
    """
    Search for chunks containing specific text or matching criteria.

    Input:
        parse_result: Parsed document
        query: Search query
        chunk_types: Optional list of chunk types to filter
        top_k: Maximum results to return

    Output:
        List of matching chunks with scores
    """

    name = "search_chunks"
    description = "Search document chunks for specific content"

    def execute(
        self,
        parse_result: Any,
        query: str,
        chunk_types: Optional[List[str]] = None,
        top_k: int = 10,
        **kwargs
    ) -> ToolResult:
        try:
            from ..chunks import ChunkType

            query_lower = query.lower()
            results = []

            for chunk in parse_result.chunks:
                # Filter by type
                if chunk_types:
                    if chunk.chunk_type.value not in chunk_types:
                        continue

                # Simple text matching with scoring
                text_lower = chunk.text.lower()
                if query_lower in text_lower:
                    # Calculate relevance score
                    count = text_lower.count(query_lower)
                    position = text_lower.find(query_lower)
                    score = count * 10 + (1 / (position + 1)) * 5

                    results.append({
                        "chunk_id": chunk.chunk_id,
                        "type": chunk.chunk_type.value,
                        "text": chunk.text[:300],
                        "page": chunk.page,
                        "score": score,
                        "bbox": chunk.bbox.xyxy,
                    })

            # Sort by score and limit
            results.sort(key=lambda x: x["score"], reverse=True)
            results = results[:top_k]

            return ToolResult(
                success=True,
                data={
                    "query": query,
                    "total_matches": len(results),
                    "results": results,
                },
            )
        except Exception as e:
            logger.error(f"Search chunks failed: {e}")
            return ToolResult(success=False, error=str(e))


class GetChunkDetailsTool(DocumentTool):
    """
    Get detailed information about a specific chunk.

    Input:
        parse_result: Parsed document
        chunk_id: ID of chunk to retrieve

    Output:
        Full chunk details including content and metadata
    """

    name = "get_chunk_details"
    description = "Get detailed information about a specific chunk"

    def execute(
        self,
        parse_result: Any,
        chunk_id: str,
        **kwargs
    ) -> ToolResult:
        try:
            from ..chunks import TableChunk, ChartChunk

            # Find chunk
            chunk = None
            for c in parse_result.chunks:
                if c.chunk_id == chunk_id:
                    chunk = c
                    break

            if chunk is None:
                return ToolResult(
                    success=False,
                    error=f"Chunk not found: {chunk_id}"
                )

            data = {
                "chunk_id": chunk.chunk_id,
                "doc_id": chunk.doc_id,
                "type": chunk.chunk_type.value,
                "text": chunk.text,
                "page": chunk.page,
                "bbox": {
                    "x_min": chunk.bbox.x_min,
                    "y_min": chunk.bbox.y_min,
                    "x_max": chunk.bbox.x_max,
                    "y_max": chunk.bbox.y_max,
                    "normalized": chunk.bbox.normalized,
                },
                "confidence": chunk.confidence,
                "sequence_index": chunk.sequence_index,
            }

            # Add type-specific data
            if isinstance(chunk, TableChunk):
                data["table"] = {
                    "num_rows": chunk.num_rows,
                    "num_cols": chunk.num_cols,
                    "markdown": chunk.to_markdown(),
                    "csv": chunk.to_csv(),
                }
            elif isinstance(chunk, ChartChunk):
                data["chart"] = {
                    "chart_type": chunk.chart_type,
                    "title": chunk.title,
                    "data_points": len(chunk.data_points),
                    "trends": chunk.trends,
                }

            return ToolResult(success=True, data=data)

        except Exception as e:
            logger.error(f"Get chunk details failed: {e}")
            return ToolResult(success=False, error=str(e))


class GetTableDataTool(DocumentTool):
    """
    Get structured data from a table chunk.

    Input:
        parse_result: Parsed document
        chunk_id: ID of table chunk
        format: Output format (json, csv, markdown)

    Output:
        Table data in requested format
    """

    name = "get_table_data"
    description = "Extract structured data from a table"

    def execute(
        self,
        parse_result: Any,
        chunk_id: str,
        format: str = "json",
        **kwargs
    ) -> ToolResult:
        try:
            from ..chunks import TableChunk

            # Find table chunk
            table = None
            for c in parse_result.chunks:
                if c.chunk_id == chunk_id and isinstance(c, TableChunk):
                    table = c
                    break

            if table is None:
                return ToolResult(
                    success=False,
                    error=f"Table chunk not found: {chunk_id}"
                )

            if format == "csv":
                data = table.to_csv()
            elif format == "markdown":
                data = table.to_markdown()
            else:  # json
                data = table.to_structured_json()

            return ToolResult(
                success=True,
                data={
                    "chunk_id": chunk_id,
                    "format": format,
                    "num_rows": table.num_rows,
                    "num_cols": table.num_cols,
                    "content": data,
                },
                evidence=[{
                    "chunk_id": chunk_id,
                    "page": table.page,
                    "bbox": table.bbox.xyxy,
                    "source_type": "table",
                }],
            )
        except Exception as e:
            logger.error(f"Get table data failed: {e}")
            return ToolResult(success=False, error=str(e))


class AnswerQuestionTool(DocumentTool):
    """
    Answer a question about the document using available chunks.

    Input:
        parse_result: Parsed document
        question: Question to answer
        use_rag: Whether to use RAG for retrieval (requires indexed document)
        document_id: Document ID for RAG retrieval (defaults to parse_result.doc_id)
        top_k: Number of chunks to consider

    Output:
        Answer with supporting evidence
    """

    name = "answer_question"
    description = "Answer a question about the document content"

    def __init__(self, llm_client=None):
        self.llm_client = llm_client

    def execute(
        self,
        parse_result: Any,
        question: str,
        use_rag: bool = False,
        document_id: Optional[str] = None,
        top_k: int = 5,
        **kwargs
    ) -> ToolResult:
        try:
            # Use RAG if requested and available
            if use_rag:
                return self._answer_with_rag(
                    question=question,
                    document_id=document_id or (parse_result.doc_id if parse_result else None),
                    top_k=top_k,
                )

            # Fall back to keyword-based search on parse_result
            return self._answer_with_keywords(
                parse_result=parse_result,
                question=question,
                top_k=top_k,
            )

        except Exception as e:
            logger.error(f"Answer question failed: {e}")
            return ToolResult(success=False, error=str(e))

    def _answer_with_rag(
        self,
        question: str,
        document_id: Optional[str],
        top_k: int,
    ) -> ToolResult:
        """Answer using RAG retrieval."""
        try:
            from .rag_tools import RAGAnswerTool
            rag_tool = RAGAnswerTool(llm_client=self.llm_client)
            return rag_tool.execute(
                question=question,
                document_id=document_id,
                top_k=top_k,
            )
        except ImportError:
            return ToolResult(
                success=False,
                error="RAG module not available. Use use_rag=False or install chromadb."
            )

    def _answer_with_keywords(
        self,
        parse_result: Any,
        question: str,
        top_k: int,
    ) -> ToolResult:
        """Answer using keyword-based search on parse_result."""
        if parse_result is None:
            return ToolResult(
                success=False,
                error="parse_result is required when use_rag=False"
            )

        # Find relevant chunks using keyword matching
        question_lower = question.lower()
        relevant_chunks = []

        for chunk in parse_result.chunks:
            text_lower = chunk.text.lower()
            # Check for keyword overlap
            keywords = [w for w in question_lower.split() if len(w) > 3]
            matches = sum(1 for k in keywords if k in text_lower)
            if matches > 0:
                relevant_chunks.append((chunk, matches))

        # Sort by relevance
        relevant_chunks.sort(key=lambda x: x[1], reverse=True)
        top_chunks = relevant_chunks[:top_k]

        if not top_chunks:
            return ToolResult(
                success=True,
                data={
                    "question": question,
                    "answer": "I could not find relevant information in the document to answer this question.",
                    "confidence": 0.0,
                    "abstained": True,
                },
            )

        # Build context
        context = "\n\n".join(
            f"[Page {c.page}] {c.text}"
            for c, _ in top_chunks
        )

        # If no LLM, return context-based answer
        if self.llm_client is None:
            return ToolResult(
                success=True,
                data={
                    "question": question,
                    "answer": f"Based on the document: {top_chunks[0][0].text[:500]}",
                    "confidence": 0.6,
                    "context_chunks": len(top_chunks),
                },
                evidence=[
                    {
                        "chunk_id": c.chunk_id,
                        "page": c.page,
                        "bbox": c.bbox.xyxy,
                        "snippet": c.text[:200],
                    }
                    for c, _ in top_chunks
                ],
            )

        # Use LLM to generate answer if available
        try:
            from ...rag import get_grounded_generator

            generator = get_grounded_generator(llm_client=self.llm_client)

            # Convert chunks to format expected by generator
            chunk_dicts = [
                {
                    "chunk_id": c.chunk_id,
                    "document_id": c.doc_id,
                    "text": c.text,
                    "similarity": score / 10.0,  # Normalize score
                    "page": c.page,
                    "chunk_type": c.chunk_type.value,
                }
                for c, score in top_chunks
            ]

            answer = generator.generate_answer(
                question=question,
                context=context,
                chunks=chunk_dicts,
            )

            return ToolResult(
                success=True,
                data={
                    "question": question,
                    "answer": answer.text,
                    "confidence": answer.confidence,
                    "abstained": answer.abstained,
                },
                evidence=[
                    {
                        "chunk_id": c.chunk_id,
                        "page": c.page,
                        "bbox": c.bbox.xyxy,
                        "snippet": c.text[:200],
                    }
                    for c, _ in top_chunks
                ],
            )

        except ImportError:
            # Fall back to simple answer without LLM generation
            return ToolResult(
                success=True,
                data={
                    "question": question,
                    "answer": f"Based on the document: {top_chunks[0][0].text[:500]}",
                    "confidence": 0.6,
                    "context_chunks": len(top_chunks),
                },
                evidence=[
                    {
                        "chunk_id": c.chunk_id,
                        "page": c.page,
                        "bbox": c.bbox.xyxy,
                        "snippet": c.text[:200],
                    }
                    for c, _ in top_chunks
                ],
            )


class CropRegionTool(DocumentTool):
    """
    Crop a region from a document page image.

    Input:
        doc_path: Path to document
        page: Page number (1-indexed)
        bbox: Bounding box (x_min, y_min, x_max, y_max)
        output_path: Optional path to save crop

    Output:
        Crop image path or base64 data
    """

    name = "crop_region"
    description = "Crop a specific region from a document page"

    def execute(
        self,
        doc_path: str,
        page: int,
        bbox: List[float],
        output_path: Optional[str] = None,
        **kwargs
    ) -> ToolResult:
        try:
            from ..io import load_document, RenderOptions
            from ..grounding import crop_region
            from ..chunks import BoundingBox
            from PIL import Image

            # Load and render page
            loader, renderer = load_document(doc_path)
            page_image = renderer.render_page(page, RenderOptions(dpi=200))
            loader.close()

            # Create bbox
            bbox_obj = BoundingBox(
                x_min=bbox[0],
                y_min=bbox[1],
                x_max=bbox[2],
                y_max=bbox[3],
                normalized=True,  # Assume normalized
            )

            # Crop
            crop = crop_region(page_image, bbox_obj)

            # Save or return
            if output_path:
                Image.fromarray(crop).save(output_path)
                return ToolResult(
                    success=True,
                    data={
                        "output_path": output_path,
                        "width": crop.shape[1],
                        "height": crop.shape[0],
                    },
                )
            else:
                import base64
                import io

                pil_img = Image.fromarray(crop)
                buffer = io.BytesIO()
                pil_img.save(buffer, format="PNG")
                b64 = base64.b64encode(buffer.getvalue()).decode()

                return ToolResult(
                    success=True,
                    data={
                        "width": crop.shape[1],
                        "height": crop.shape[0],
                        "base64": b64[:100] + "...",  # Truncated for display
                    },
                )

        except Exception as e:
            logger.error(f"Crop region failed: {e}")
            return ToolResult(success=False, error=str(e))


# Tool registry for agent use
DOCUMENT_TOOLS = {
    "parse_document": ParseDocumentTool,
    "extract_fields": ExtractFieldsTool,
    "search_chunks": SearchChunksTool,
    "get_chunk_details": GetChunkDetailsTool,
    "get_table_data": GetTableDataTool,
    "answer_question": AnswerQuestionTool,
    "crop_region": CropRegionTool,
}


def get_tool(name: str, **kwargs) -> DocumentTool:
    """Get a tool instance by name."""
    if name not in DOCUMENT_TOOLS:
        raise ValueError(f"Unknown tool: {name}")
    return DOCUMENT_TOOLS[name](**kwargs)


def list_tools() -> List[Dict[str, str]]:
    """List all available tools."""
    return [
        {"name": name, "description": cls.description}
        for name, cls in DOCUMENT_TOOLS.items()
    ]