#!/usr/bin/env python3
"""
PostToolUse hook to block bd create/update commands with truncation markers.

Prevents incomplete task specifications from being saved to bd, which causes
confusion and incomplete implementation later.

Truncation markers include:
- [Remaining step groups truncated for length]
- [truncated]
- [... (more)]
- [etc.]
- [Omitted for brevity]
"""

import json
import sys
import re

# Truncation markers to detect
TRUNCATION_PATTERNS = [
    r'\[Remaining.*?truncated',
    r'\[truncated',
    r'\[\.\.\..*?\]',
    r'\[etc\.?\]',
    r'\[Omitted.*?\]',
    r'\[More.*?omitted\]',
    r'\[Full.*?not shown\]',
    r'\[Additional.*?omitted\]',
    r'\.\.\..*?\[',  # ... [something]
    r'\(truncated\)',
    r'\(abbreviated\)',
]

def check_for_truncation(text):
    """Check if text contains any truncation markers."""
    if not text:
        return None

    for pattern in TRUNCATION_PATTERNS:
        match = re.search(pattern, text, re.IGNORECASE)
        if match:
            return match.group(0)

    return None

def main():
    # Read tool use event from stdin
    try:
        input_data = json.load(sys.stdin)
    except json.JSONDecodeError:
        # If we can't parse JSON, allow the operation
        sys.exit(0)

    tool_name = input_data.get("tool_name", "")
    tool_input = input_data.get("tool_input", {})

    # Only check Bash tool calls
    if tool_name != "Bash":
        sys.exit(0)

    command = tool_input.get("command", "")

    # Check if this is a bd create or bd update command
    if not command or not re.search(r'\bbd\s+(create|update)\b', command):
        sys.exit(0)

    # Check for truncation markers
    truncation_marker = check_for_truncation(command)

    if truncation_marker:
        # Block the command and provide helpful feedback
        output = {
            "hookSpecificOutput": {
                "hookEventName": "PostToolUse",
                "permissionDecision": "deny",
                "permissionDecisionReason": (
                    f"⚠️  BD TRUNCATION DETECTED\n\n"
                    f"Found truncation marker: {truncation_marker}\n\n"
                    f"This bd task specification appears incomplete or truncated. "
                    f"Saving incomplete specifications leads to confusion and incomplete implementations.\n\n"
                    f"Please:\n"
                    f"1. Expand the full implementation details\n"
                    f"2. Include ALL step groups and tasks\n"
                    f"3. Do not use truncation markers like '[Remaining steps truncated]'\n"
                    f"4. Ensure every step has complete, actionable instructions\n\n"
                    f"If the specification is too long:\n"
                    f"- Break into smaller epics\n"
                    f"- Use bd dependencies to link related tasks\n"
                    f"- Focus on making each task independently complete\n\n"
                    f"DO NOT truncate task specifications."
                )
            }
        }
        print(json.dumps(output))
        sys.exit(0)

    # Allow command if no truncation detected
    sys.exit(0)

if __name__ == "__main__":
    main()