"""
CLI Entry Point and Basic Commands - Issue #12

This module provides the command-line interface for MarkiTect, allowing users
to interact with core functionality through terminal commands.

Commands:
- ingest: Process and store a markdown file
- status: Show processing status and metadata for a file
- list: List all stored files and their status

Integration with existing components:
- Uses DatabaseManager for file storage and retrieval
- Uses DocumentManager for high-performance document processing
- Maintains performance caching architecture
"""

import click
import os
import sys
import json
from pathlib import Path
from typing import Optional

from .database import DatabaseManager
from .document_manager import DocumentManager
from .serializer import ASTSerializer


# Global options for CLI configuration
pass_config = click.make_pass_decorator(dict, ensure=True)


@click.group()
@click.option('--verbose', '-v', is_flag=True, help='Enable verbose output')
@click.option('--config', 'config_file', type=click.Path(exists=True), help='Configuration file path')
@click.option('--database', type=click.Path(), help='Database file path')
@pass_config
def cli(config, verbose, database, config_file):
    """
    MarkiTect - Advanced Markdown engine for structured content.

    Process markdown files with front matter support, AST caching,
    and relational metadata queries.

    Examples:
        markitect ingest document.md     # Process a markdown file
        markitect status document.md     # Check file status
        markitect list                   # List all stored files
    """
    # Store configuration in context
    config['verbose'] = verbose
    config['config_file'] = config_file

    # Determine database path
    if database:
        config['database_path'] = database
    else:
        # Default database location
        config['database_path'] = os.path.expanduser('~/.markitect/markitect.db')

    # Initialize database manager and ensure database exists
    try:
        db_manager = DatabaseManager(config['database_path'])
        db_manager.initialize_database()
        config['db_manager'] = db_manager

        if verbose:
            click.echo(f"Using database: {config['database_path']}", err=True)
    except Exception as e:
        click.echo(f"Error initializing database: {e}", err=True)
        sys.exit(1)


@cli.command()
@click.argument('file_path', type=click.Path(exists=True))
@pass_config
def ingest(config, file_path):
    """
    Process and store a markdown file.

    Ingests a markdown file into the MarkiTect system, parsing its content,
    extracting front matter, generating AST cache, and storing metadata
    in the database.

    FILE_PATH: Path to the markdown file to process

    Examples:
        markitect ingest README.md
        markitect ingest docs/guide.md
    """
    try:
        file_path = Path(file_path)

        if config['verbose']:
            click.echo(f"Processing file: {file_path}")

        # Initialize document manager with database manager
        doc_manager = DocumentManager(config['db_manager'])

        # Ingest the file
        result = doc_manager.ingest_file(file_path)

        if config['verbose']:
            click.echo(f"Processing results:")
            click.echo(f"  File: {result['metadata']['filename']}")
            click.echo(f"  AST nodes: {len(result['ast'])} nodes")
            click.echo(f"  Cache file: {result['ast_cache_path']}")
            click.echo(f"  Parse time: {result['parse_time']:.2f}s")
            click.echo(f"  Cache time: {result['cache_time']:.2f}s")

        click.echo(f"✓ Successfully ingested: {file_path.name}")

    except FileNotFoundError:
        click.echo(f"Error: File not found: {file_path}", err=True)
        sys.exit(1)
    except PermissionError:
        click.echo(f"Error: Permission denied accessing: {file_path}", err=True)
        sys.exit(1)
    except Exception as e:
        click.echo(f"Error processing file: {e}", err=True)
        if config['verbose']:
            import traceback
            click.echo(traceback.format_exc(), err=True)
        sys.exit(1)


@cli.command()
@click.argument('file_path', type=str)
@pass_config
def status(config, file_path):
    """
    Show processing status and metadata for a file.

    Displays information about a file's processing status, metadata,
    and front matter content from the database.

    FILE_PATH: Path or name of the file to check

    Examples:
        markitect status README.md
        markitect status docs/guide.md
    """
    try:
        if config['verbose']:
            click.echo(f"Checking status for: {file_path}")

        # Get file information from database
        db_manager = config['db_manager']
        file_info = db_manager.get_markdown_file(file_path)

        if file_info:
            click.echo(f"File: {file_info['filename']}")
            click.echo(f"Status: Processed")
            click.echo(f"Created: {file_info['created_at']}")

            if file_info['front_matter']:
                try:
                    front_matter = eval(file_info['front_matter'])  # Safe for our controlled data
                    if front_matter:
                        click.echo("Front Matter:")
                        for key, value in front_matter.items():
                            click.echo(f"  {key}: {value}")
                except (ValueError, TypeError, SyntaxError):
                    click.echo("Front Matter: (parsing error)")
            elif file_info['front_matter'] is None:
                pass  # No front matter to display

            if config['verbose']:
                content_preview = file_info['content'][:200] + "..." if len(file_info['content']) > 200 else file_info['content']
                click.echo(f"Content preview: {content_preview}")
        else:
            click.echo(f"File not found in database: {file_path}")
            click.echo("Use 'markitect ingest' to process the file first.")
            sys.exit(1)

    except Exception as e:
        click.echo(f"Error checking file status: {e}", err=True)
        if config['verbose']:
            import traceback
            click.echo(traceback.format_exc(), err=True)
        sys.exit(1)


@cli.command()
@click.argument('file_path', type=str)
@click.option('--output', '-o', type=click.Path(), help='Output file path (default: stdout)')
@pass_config
def get(config, file_path, output):
    """
    Retrieve and output a processed markdown file.

    Loads the file from the database and AST cache, then serializes it back
    to markdown format. Supports outputting to file or stdout.

    FILE_PATH: Name of the file to retrieve

    Examples:
        markitect get README.md
        markitect get docs/guide.md --output modified_guide.md
    """
    try:
        if config['verbose']:
            click.echo(f"Retrieving file: {file_path}")

        db_manager = config['db_manager']

        # Get file information from database
        file_info = db_manager.get_markdown_file(file_path)
        if not file_info:
            click.echo(f"File not found in database: {file_path}", err=True)
            click.echo("Use 'markitect ingest' to process the file first.", err=True)
            sys.exit(1)

        # Load AST from cache
        cache_filename = f"{file_path}.ast.json"
        cache_path = Path('.ast_cache') / cache_filename

        if not cache_path.exists():
            click.echo(f"AST cache not found: {cache_path}", err=True)
            click.echo("Try re-ingesting the file to regenerate cache.", err=True)
            sys.exit(1)

        # Read AST from cache
        with open(cache_path, 'r', encoding='utf-8') as f:
            ast = json.load(f)

        # Parse front matter from database
        front_matter = None
        if file_info.get('front_matter'):
            try:
                front_matter = eval(file_info['front_matter'])
            except (ValueError, TypeError, SyntaxError):
                if config['verbose']:
                    click.echo("Warning: Could not parse front matter", err=True)

        # Serialize AST back to markdown
        serializer = ASTSerializer()
        markdown_content = serializer.serialize_to_markdown(ast, front_matter)

        # Output to file or stdout
        if output:
            output_path = Path(output)
            output_path.parent.mkdir(parents=True, exist_ok=True)
            with open(output_path, 'w', encoding='utf-8') as f:
                f.write(markdown_content)
            click.echo(f"✓ File written to: {output_path}")
        else:
            click.echo(markdown_content)

        if config['verbose']:
            click.echo(f"Retrieved {len(ast)} AST tokens", err=True)

    except Exception as e:
        click.echo(f"Error retrieving file: {e}", err=True)
        if config['verbose']:
            import traceback
            click.echo(traceback.format_exc(), err=True)
        sys.exit(1)


@cli.command()
@click.argument('file_path', type=str)
@click.option('--add-section', type=str, help='Add section with title')
@click.option('--section-content', type=str, default='', help='Content for new section')
@click.option('--section-level', type=int, default=2, help='Heading level for new section (1-6)')
@click.option('--update-front-matter', type=str, help='Update front matter (format: key:value)')
@click.option('--output', '-o', type=click.Path(), help='Output file path (default: overwrite original in cache)')
@pass_config
def modify(config, file_path, add_section, section_content, section_level, update_front_matter, output):
    """
    Modify the content of a processed markdown file.

    Loads the file from cache, applies modifications, and updates the cache
    or outputs to a new file. Supports adding sections and updating front matter.

    FILE_PATH: Name of the file to modify

    Examples:
        markitect modify README.md --add-section "New Section" --section-content "New content"
        markitect modify doc.md --update-front-matter "status:updated"
        markitect modify doc.md --add-section "Notes" --output modified_doc.md
    """
    try:
        if config['verbose']:
            click.echo(f"Modifying file: {file_path}")

        db_manager = config['db_manager']

        # Get file information from database
        file_info = db_manager.get_markdown_file(file_path)
        if not file_info:
            click.echo(f"File not found in database: {file_path}", err=True)
            click.echo("Use 'markitect ingest' to process the file first.", err=True)
            sys.exit(1)

        # Load AST from cache
        cache_filename = f"{file_path}.ast.json"
        cache_path = Path('.ast_cache') / cache_filename

        if not cache_path.exists():
            click.echo(f"AST cache not found: {cache_path}", err=True)
            click.echo("Try re-ingesting the file to regenerate cache.", err=True)
            sys.exit(1)

        # Read AST from cache
        with open(cache_path, 'r', encoding='utf-8') as f:
            ast = json.load(f)

        # Parse front matter from database
        front_matter = {}
        if file_info.get('front_matter'):
            try:
                front_matter = eval(file_info['front_matter']) or {}
            except (ValueError, TypeError, SyntaxError):
                if config['verbose']:
                    click.echo("Warning: Could not parse existing front matter", err=True)

        # Prepare modifications
        modifications = {}
        changes_made = []

        # Handle add-section modification
        if add_section:
            modifications['add_section'] = {
                'title': add_section,
                'content': section_content,
                'level': section_level
            }
            changes_made.append(f"Added section: {add_section}")

        # Handle front matter updates
        if update_front_matter:
            try:
                if ':' in update_front_matter:
                    key, value = update_front_matter.split(':', 1)
                    key = key.strip()
                    value = value.strip()

                    # Try to parse value as appropriate type
                    if value.lower() in ['true', 'false']:
                        value = value.lower() == 'true'
                    elif value.isdigit():
                        value = int(value)
                    elif value.replace('.', '').isdigit():
                        value = float(value)

                    front_matter[key] = value
                    changes_made.append(f"Updated front matter: {key} = {value}")
                else:
                    click.echo("Invalid front matter format. Use 'key:value'", err=True)
                    sys.exit(1)
            except ValueError as e:
                click.echo(f"Error parsing front matter update: {e}", err=True)
                sys.exit(1)

        if not changes_made:
            click.echo("No modifications specified. Use --add-section or --update-front-matter", err=True)
            sys.exit(1)

        # Apply modifications to AST
        serializer = ASTSerializer()
        if modifications:
            ast = serializer.modify_ast_content(ast, modifications)

        # Serialize back to markdown
        markdown_content = serializer.serialize_to_markdown(ast, front_matter)

        # Handle output
        if output:
            # Write to specified output file
            output_path = Path(output)
            output_path.parent.mkdir(parents=True, exist_ok=True)
            with open(output_path, 'w', encoding='utf-8') as f:
                f.write(markdown_content)
            click.echo(f"✓ Modified file written to: {output_path}")
        else:
            # Update the cache and database with modifications
            with open(cache_path, 'w', encoding='utf-8') as f:
                json.dump(ast, f, indent=2, ensure_ascii=False)

            # Update database with new front matter
            if front_matter:
                # Note: This would require extending DatabaseManager to update front matter
                # For now, we'll just note the modification
                if config['verbose']:
                    click.echo("Note: Database front matter update not implemented yet", err=True)

            click.echo(f"✓ Modified file updated in cache: {file_path}")

        # Show changes made
        if config['verbose']:
            click.echo("Changes applied:", err=True)
            for change in changes_made:
                click.echo(f"  - {change}", err=True)

    except Exception as e:
        click.echo(f"Error modifying file: {e}", err=True)
        if config['verbose']:
            import traceback
            click.echo(traceback.format_exc(), err=True)
        sys.exit(1)


@cli.command()
@pass_config
def list(config):
    """
    List all stored files and their status.

    Shows all markdown files that have been processed and stored
    in the MarkiTect database with their basic metadata.

    Examples:
        markitect list
        markitect --verbose list    # Show detailed information
    """
    try:
        if config['verbose']:
            click.echo("Retrieving all stored files...")

        db_manager = config['db_manager']
        files = db_manager.list_markdown_files()

        if not files:
            click.echo("No files found in database.")
            click.echo("Use 'markitect ingest <file>' to add files.")
            return

        click.echo(f"Found {len(files)} file(s):")
        click.echo()

        for file_info in files:
            click.echo(f"📄 {file_info['filename']}")
            if config['verbose']:
                click.echo(f"   Created: {file_info['created_at']}")
                if file_info.get('front_matter'):
                    try:
                        front_matter = eval(file_info['front_matter'])
                        if front_matter:
                            click.echo(f"   Front matter: {list(front_matter.keys())}")
                    except (ValueError, TypeError, SyntaxError):
                        click.echo(f"   Front matter: (parsing error)")
                click.echo()

    except Exception as e:
        click.echo(f"Error listing files: {e}", err=True)
        if config['verbose']:
            import traceback
            click.echo(traceback.format_exc(), err=True)
        sys.exit(1)


def main():
    """
    Main entry point for the CLI.

    This function is referenced in pyproject.toml console_scripts.
    """
    try:
        cli()
    except KeyboardInterrupt:
        click.echo("\nOperation interrupted by user.", err=True)
        sys.exit(130)  # Standard exit code for SIGINT
    except Exception as e:
        click.echo(f"Unexpected error: {e}", err=True)
        sys.exit(1)


if __name__ == '__main__':
    main()