# language_checker.py
import re
import traceback
from typing import List, Dict, Any
import language_tool_python

from text_utils import convert_markdown_to_plain_text
# config.py (setting JAVA_HOME) should be imported early in app.py

def perform_language_checks(markdown_text_from_filtered_pdf: str) -> Dict[str, Any]:
    """
    Performs LanguageTool checks on plain text derived from font-filtered Markdown.
    Filters issues to only include those between "abstract" and "references/bibliography"
    found within this specific text.
    """
    if not markdown_text_from_filtered_pdf or not markdown_text_from_filtered_pdf.strip():
        print("LT_Checker: Input Markdown text is empty.")
        return {"total_issues": 0, "issues_list": [], "text_used_for_analysis": ""}

    plain_text_from_markdown = convert_markdown_to_plain_text(markdown_text_from_filtered_pdf)
    text_for_lt_analysis = plain_text_from_markdown.replace('\n', ' ')
    text_for_lt_analysis = re.sub(r'\s+', ' ', text_for_lt_analysis).strip()

    if not text_for_lt_analysis:
        print("LT_Checker: Plain text derived from Markdown is empty after cleaning.")
        return {"total_issues": 0, "issues_list": [], "text_used_for_analysis": ""}

    text_for_lt_analysis_lower = text_for_lt_analysis.lower()
    
    abstract_match = re.search(r'\babstract\b', text_for_lt_analysis_lower)
    content_start_index = abstract_match.start() if abstract_match else 0
    if abstract_match:
        print(f"LT_Checker: Found 'abstract' at index {content_start_index} in its text.")
    else:
        print(f"LT_Checker: Did not find 'abstract', LT analysis from index 0 of its text.")

    # Determine end boundary (references or bibliography)
    references_match = re.search(r'\breferences\b', text_for_lt_analysis_lower)
    bibliography_match = re.search(r'\bbibliography\b', text_for_lt_analysis_lower)
    content_end_index = len(text_for_lt_analysis)

    if references_match and bibliography_match:
        content_end_index = min(references_match.start(), bibliography_match.start())
        print(f"LT_Checker: Found 'references' at {references_match.start()} and 'bibliography' at {bibliography_match.start()}. Using {content_end_index} as end boundary.")
    elif references_match:
        content_end_index = references_match.start()
        print(f"LT_Checker: Found 'references' at {content_end_index}. Using it as end boundary.")
    elif bibliography_match:
        content_end_index = bibliography_match.start()
        print(f"LT_Checker: Found 'bibliography' at {content_end_index}. Using it as end boundary.")
    else:
        print(f"LT_Checker: Did not find 'references' or 'bibliography'. LT analysis up to end of its text (index {content_end_index}).")

    if content_start_index >= content_end_index:
        print(f"LT_Checker: Warning: Content start index ({content_start_index}) is not before end index ({content_end_index}) in its text. No LT issues will be reported from this range.")
    
    tool = None
    processed_lt_issues: List[Dict[str, Any]] = []
    try:
        tool = language_tool_python.LanguageTool('en-US') 
        raw_lt_matches = tool.check(text_for_lt_analysis)
        
        lt_issues_in_range = 0
        for idx, match in enumerate(raw_lt_matches):
            if match.ruleId == "EN_SPLIT_WORDS_HYPHEN": continue  # Common rule to ignore

            if not (content_start_index <= match.offset < content_end_index):
                continue
            lt_issues_in_range += 1

            # Text of the error itself
            error_text_verbatim = match.matchedText # The actual text that LanguageTool flagged

            # New context extraction for ~10 words:
            words_around = 1  # Number of words to try and get on each side

            # Text before the error
            pre_error_text = text_for_lt_analysis[:match.offset]
            words_before = pre_error_text.split()[-words_around:]

            # Text after the error
            post_error_text = text_for_lt_analysis[match.offset + match.errorLength:]
            words_after = post_error_text.split()[:words_around]

            # Combine to form the new wider context
            context_parts = []
            if words_before:
                context_parts.append(" ".join(words_before))
            context_parts.append(error_text_verbatim)  # The actual error phrase
            if words_after:
                context_parts.append(" ".join(words_after))

            wider_context_str = " ".join(context_parts)

            processed_lt_issues.append({
                '_internal_id': f"lt_{idx}",
                'ruleId': match.ruleId,
                'message': match.message,
                'context_text': wider_context_str,
                'error_text_verbatim': error_text_verbatim, # Store the verbatim error text
                'offset_in_text': match.offset,
                'error_length': match.errorLength,
                'replacements_suggestion': match.replacements[:3] if match.replacements else [],
                'category_name': match.category,
                'source_check_type': 'LanguageTool',
                'is_mapped_to_pdf': False,
                'pdf_coordinates_list': [],
                'mapped_page_number': -1
            })
        print(f"LT_Checker: LanguageTool found {len(raw_lt_matches)} raw issues, {lt_issues_in_range} issues within defined content range of its text.")
        
        return {
            "total_issues": len(processed_lt_issues),
            "issues_list": processed_lt_issues,
            "text_used_for_analysis": text_for_lt_analysis 
        }
    except Exception as e:
        print(f"Error in perform_language_checks: {e}\n{traceback.format_exc()}")
        return {"error": str(e), "total_issues": 0, "issues_list": [], "text_used_for_analysis": text_for_lt_analysis}
    finally:
        if tool:
            tool.close()