"""
Word Document Parser Module

This module handles DOCX document parsing using python-docx for text, formatting,
and structure extraction, including sections, paragraphs, tables, and metadata.

Key Features:
    - DOCX text and formatting extraction
    - Document structure analysis (sections, headings)
    - Table extraction
    - Metadata extraction (title, author, dates)
    - Paragraph and style information
    - Embedded image handling

Main Classes:
    - DOCXParser: DOCX document parser
    - DocxSection: Dataclass for document section representation
    - DocxMetadata: Dataclass for document metadata representation

Example Usage:
    >>> from semantica.parse import DOCXParser
    >>> parser = DOCXParser()
    >>> text = parser.parse("document.docx")
    >>> sections = parser.extract_sections("document.docx")
    >>> metadata = parser.extract_metadata("document.docx")

Author: Semantica Contributors
License: MIT
"""

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

from docx import Document
from docx.document import Document as DocxDocument
from docx.oxml.table import CT_Tbl
from docx.oxml.text.paragraph import CT_P
from docx.table import Table
from docx.text.paragraph import Paragraph

from ..utils.exceptions import ProcessingError, ValidationError
from ..utils.logging import get_logger
from ..utils.progress_tracker import get_progress_tracker


@dataclass
class DocxSection:
    """Document section representation."""

    heading: str
    level: int
    content: str
    paragraphs: List[str] = field(default_factory=list)
    tables: List[Dict[str, Any]] = field(default_factory=list)


@dataclass
class DocxMetadata:
    """Document metadata representation."""

    title: Optional[str] = None
    author: Optional[str] = None
    subject: Optional[str] = None
    keywords: Optional[str] = None
    comments: Optional[str] = None
    category: Optional[str] = None
    created: Optional[str] = None
    modified: Optional[str] = None
    last_modified_by: Optional[str] = None


class DOCXParser:
    """DOCX document parser."""

    def __init__(self, **config):
        """
        Initialize DOCX parser.

        Args:
            **config: Parser configuration
        """
        self.logger = get_logger("docx_parser")
        self.config = config
        self.progress_tracker = get_progress_tracker()

    def parse(self, file_path: Union[str, Path], pipeline_id: Optional[str] = None, **options) -> Dict[str, Any]:
        """
        Parse DOCX document.

        Args:
            file_path: Path to DOCX file
            pipeline_id: Optional pipeline ID for progress tracking
            **options: Parsing options:
                - extract_formatting: Whether to extract formatting (default: False)
                - extract_tables: Whether to extract tables (default: True)
                - extract_comments: Whether to extract comments (default: False)

        Returns:
            dict: Parsed document data
        """
        file_path = Path(file_path)

        # Track DOCX parsing
        tracking_id = self.progress_tracker.start_tracking(
            file=str(file_path),
            module="parse",
            submodule="DOCXParser",
            message=f"DOCX: {file_path.name}",
            pipeline_id=pipeline_id,
        )

        try:
            if not file_path.exists():
                raise ValidationError(f"DOCX file not found: {file_path}")

            if not file_path.suffix.lower() in [".docx", ".doc"]:
                raise ValidationError(f"File is not a DOCX: {file_path}")

            try:
                doc = Document(str(file_path))

                # Extract metadata
                metadata = self._extract_metadata(doc)

                # Extract paragraphs
                paragraphs = []
                for para in doc.paragraphs:
                    if para.text.strip():
                        paragraphs.append(para.text.strip())

                # Extract tables
                tables = []
                if options.get("extract_tables", True):
                    for table in doc.tables:
                        table_data = self._extract_table(table)
                        tables.append(table_data)

                # Extract structure
                sections = self._extract_sections(doc, options)

                # Extract comments if requested
                comments = []
                if options.get("extract_comments", False):
                    comments = self._extract_comments(doc)

                # Extract formatting if requested
                formatting_info = None
                if options.get("extract_formatting", False):
                    formatting_info = self._extract_formatting(doc)

                self.progress_tracker.stop_tracking(
                    tracking_id,
                    status="completed",
                    message=f"Parsed {len(paragraphs)} paragraphs, {len(tables)} tables",
                )
                return {
                    "metadata": metadata.__dict__,
                    "full_text": "\n\n".join(paragraphs),
                    "paragraphs": paragraphs,
                    "tables": tables,
                    "sections": [s.__dict__ for s in sections],
                    "comments": comments,
                    "formatting": formatting_info,
                    "total_paragraphs": len(paragraphs),
                    "total_tables": len(tables),
                }

            except Exception as e:
                self.progress_tracker.stop_tracking(
                    tracking_id, status="failed", message=str(e)
                )
                self.logger.error(f"Failed to parse DOCX {file_path}: {e}")
                raise ProcessingError(f"Failed to parse DOCX: {e}")

        except Exception as e:
            self.progress_tracker.stop_tracking(
                tracking_id, status="failed", message=str(e)
            )
            raise

    def extract_text(self, file_path: Union[str, Path]) -> str:
        """
        Extract text from DOCX.

        Args:
            file_path: Path to DOCX file

        Returns:
            str: Extracted text
        """
        result = self.parse(
            file_path,
            extract_tables=False,
            extract_comments=False,
            extract_formatting=False,
        )
        return result["full_text"]

    def extract_tables(self, file_path: Union[str, Path]) -> List[Dict[str, Any]]:
        """
        Extract tables from DOCX.

        Args:
            file_path: Path to DOCX file

        Returns:
            list: Extracted tables
        """
        result = self.parse(file_path, extract_formatting=False, extract_comments=False)
        return result["tables"]

    def _extract_table(self, table: Table) -> Dict[str, Any]:
        """Extract data from table."""
        table_data = {
            "rows": [],
            "row_count": len(table.rows),
            "col_count": len(table.columns) if table.rows else 0,
        }

        for row in table.rows:
            row_data = []
            for cell in row.cells:
                row_data.append(cell.text.strip())
            table_data["rows"].append(row_data)

        return table_data

    def _extract_sections(
        self, doc: DocxDocument, options: Dict[str, Any]
    ) -> List[DocxSection]:
        """Extract document sections based on headings."""
        sections = []
        current_section = None

        for para in doc.paragraphs:
            # Check if paragraph is a heading
            if para.style.name.startswith("Heading"):
                # Get heading level
                level = (
                    int(para.style.name.split()[-1])
                    if para.style.name.split()[-1].isdigit()
                    else 1
                )

                # Save previous section if exists
                if current_section:
                    sections.append(current_section)

                # Create new section
                current_section = DocxSection(
                    heading=para.text.strip(),
                    level=level,
                    content="",
                    paragraphs=[],
                    tables=[],
                )
            elif current_section:
                # Add paragraph to current section
                if para.text.strip():
                    current_section.paragraphs.append(para.text.strip())
                    current_section.content += para.text.strip() + "\n\n"

        # Add last section
        if current_section:
            sections.append(current_section)

        return sections

    def _extract_metadata(self, doc: DocxDocument) -> DocxMetadata:
        """Extract document metadata."""
        core_props = doc.core_properties

        return DocxMetadata(
            title=core_props.title,
            author=core_props.author,
            subject=core_props.subject,
            keywords=core_props.keywords,
            comments=core_props.comments,
            category=core_props.category,
            created=str(core_props.created) if core_props.created else None,
            modified=str(core_props.modified) if core_props.modified else None,
            last_modified_by=core_props.last_modified_by,
        )

    def _extract_comments(self, doc: DocxDocument) -> List[Dict[str, Any]]:
        """Extract comments from document."""
        comments = []
        # Note: python-docx doesn't directly support comments
        # This would require additional processing
        return comments

    def _extract_formatting(self, doc: DocxDocument) -> Dict[str, Any]:
        """Extract formatting information."""
        formatting = {"paragraphs": []}

        for para in doc.paragraphs:
            para_formatting = {
                "text": para.text,
                "style": para.style.name,
                "alignment": str(para.alignment) if para.alignment else None,
                "runs": [],
            }

            for run in para.runs:
                run_formatting = {
                    "text": run.text,
                    "bold": run.bold,
                    "italic": run.italic,
                    "underline": run.underline,
                    "font_name": run.font.name if run.font.name else None,
                    "font_size": run.font.size.pt if run.font.size else None,
                }
                para_formatting["runs"].append(run_formatting)

            formatting["paragraphs"].append(para_formatting)

        return formatting
