#!/usr/bin/env python3
"""
Rename a plural slot to singular form following Rule 43.

This script:
1. Renames the slot file (identifiers.yaml → identifier.yaml)
2. Updates slot name inside the file
3. Updates all class files that reference the slot
4. Preserves natural language descriptions containing the plural word

Usage:
    python scripts/rename_plural_slot.py identifiers identifier --dry-run
    python scripts/rename_plural_slot.py identifiers identifier
"""

import argparse
import os
import re
import sys
from pathlib import Path

SLOTS_DIR = Path("schemas/20251121/linkml/modules/slots")
CLASSES_DIR = Path("schemas/20251121/linkml/modules/classes")


def rename_slot_file(old_name: str, new_name: str, dry_run: bool = False) -> bool:
    """Rename the slot YAML file and update its contents."""
    old_path = SLOTS_DIR / f"{old_name}.yaml"
    new_path = SLOTS_DIR / f"{new_name}.yaml"
    
    if not old_path.exists():
        print(f"ERROR: Slot file not found: {old_path}")
        return False
    
    if new_path.exists():
        print(f"ERROR: Target slot file already exists: {new_path}")
        return False
    
    # Read the file
    content = old_path.read_text()
    
    # Update the slot definition inside the file
    # Pattern 1: id field
    content = re.sub(
        rf"^id: (.*/slot/){old_name}$",
        rf"id: \g<1>{new_name}",
        content,
        flags=re.MULTILINE
    )
    
    # Pattern 2: name field (e.g., name: identifiers_slot → name: identifier_slot)
    content = re.sub(
        rf"^name: {old_name}_slot$",
        f"name: {new_name}_slot",
        content,
        flags=re.MULTILINE
    )
    content = re.sub(
        rf"^name: {old_name}$",
        f"name: {new_name}",
        content,
        flags=re.MULTILINE
    )
    
    # Pattern 3: slots section - the slot key itself
    # Be careful: only match when it's a YAML key (followed by :)
    content = re.sub(
        rf"^(slots:\s*\n  ){old_name}:",
        rf"\g<1>{new_name}:",
        content,
        flags=re.MULTILINE
    )
    # Also handle when the slot key is not right after slots:
    content = re.sub(
        rf"^  {old_name}:$",
        f"  {new_name}:",
        content,
        flags=re.MULTILINE
    )
    
    if dry_run:
        print(f"[DRY-RUN] Would rename: {old_path} → {new_path}")
        print(f"[DRY-RUN] Updated content preview:")
        # Show first 30 lines
        for i, line in enumerate(content.split('\n')[:30], 1):
            print(f"  {i:3d}| {line}")
    else:
        # Write the updated content
        new_path.write_text(content)
        # Remove the old file
        old_path.unlink()
        print(f"✓ Renamed slot file: {old_path.name} → {new_path.name}")
    
    return True


def update_class_files(old_name: str, new_name: str, dry_run: bool = False) -> int:
    """Update all class files that reference the slot."""
    updated_count = 0
    
    for class_file in sorted(CLASSES_DIR.glob("*.yaml")):
        content = class_file.read_text()
        original_content = content
        
        # Pattern 1: Import statement
        # - ../slots/identifiers → - ../slots/identifier
        content = re.sub(
            rf"^(- \.\./slots/){old_name}$",
            rf"\g<1>{new_name}",
            content,
            flags=re.MULTILINE
        )
        
        # Pattern 2: Slot reference in slots list (under class definition)
        # slots:
        #   - identifiers
        content = re.sub(
            rf"^(\s+- ){old_name}$",
            rf"\g<1>{new_name}",
            content,
            flags=re.MULTILINE
        )
        
        # Pattern 3: Slot usage as YAML key (indented)
        # Be careful: only match YAML keys (word at start of logical line, followed by :)
        # This handles cases like:
        #       identifiers:
        #         range: CustodianIdentifier
        # But NOT: "External identifiers assigned"
        content = re.sub(
            rf"^(\s+){old_name}:$",
            rf"\g<1>{new_name}:",
            content,
            flags=re.MULTILINE
        )
        
        # Also handle key with value on same line
        content = re.sub(
            rf"^(\s+){old_name}: ",
            rf"\g<1>{new_name}: ",
            content,
            flags=re.MULTILINE
        )
        
        if content != original_content:
            updated_count += 1
            if dry_run:
                print(f"[DRY-RUN] Would update: {class_file.name}")
                # Show diff-like output
                old_lines = original_content.split('\n')
                new_lines = content.split('\n')
                for i, (old, new) in enumerate(zip(old_lines, new_lines), 1):
                    if old != new:
                        print(f"  Line {i}:")
                        print(f"    - {old}")
                        print(f"    + {new}")
            else:
                class_file.write_text(content)
                print(f"✓ Updated class: {class_file.name}")
    
    return updated_count


def main():
    parser = argparse.ArgumentParser(
        description="Rename a plural slot to singular form (Rule 43)"
    )
    parser.add_argument("old_name", help="Current slot name (e.g., 'identifiers')")
    parser.add_argument("new_name", help="New slot name (e.g., 'identifier')")
    parser.add_argument("--dry-run", action="store_true", 
                       help="Show what would be changed without making changes")
    
    args = parser.parse_args()
    
    # Change to repo root
    repo_root = Path(__file__).parent.parent
    os.chdir(repo_root)
    
    print(f"{'='*60}")
    print(f"Renaming slot: {args.old_name} → {args.new_name}")
    print(f"Mode: {'DRY-RUN' if args.dry_run else 'LIVE'}")
    print(f"{'='*60}")
    
    # Step 1: Rename slot file
    print("\n[Step 1] Renaming slot file...")
    if not rename_slot_file(args.old_name, args.new_name, args.dry_run):
        sys.exit(1)
    
    # Step 2: Update class files
    print("\n[Step 2] Updating class files...")
    count = update_class_files(args.old_name, args.new_name, args.dry_run)
    print(f"\n{'Would update' if args.dry_run else 'Updated'} {count} class files")
    
    if args.dry_run:
        print("\n[DRY-RUN] No changes made. Run without --dry-run to apply changes.")
    else:
        print(f"\n✓ Successfully renamed slot: {args.old_name} → {args.new_name}")


if __name__ == "__main__":
    main()