#!/usr/bin/env python3
"""
Add BLOCKED dependency tree reference to all sprint files.
"""

import os
import re
from pathlib import Path

DOCS_DIR = Path(__file__).parent.parent / "docs"
IMPLPLAN_DIR = DOCS_DIR / "implplan"
ROUTER_DIR = DOCS_DIR / "router"

# Reference lines with correct relative paths
REFERENCE_LINE_IMPLPLAN = "\n> **BLOCKED Tasks:** Before working on BLOCKED tasks, review [BLOCKED_DEPENDENCY_TREE.md](./BLOCKED_DEPENDENCY_TREE.md) for root blockers and dependencies.\n"
REFERENCE_LINE_ROUTER = "\n> **BLOCKED Tasks:** Before working on BLOCKED tasks, review [../implplan/BLOCKED_DEPENDENCY_TREE.md](../implplan/BLOCKED_DEPENDENCY_TREE.md) for root blockers and dependencies.\n"

def add_reference_to_sprint(filepath: Path, reference_line: str) -> bool:
    """Add BLOCKED reference to a sprint file. Returns True if modified."""
    content = filepath.read_text(encoding="utf-8")

    # Skip if reference already exists
    if "BLOCKED_DEPENDENCY_TREE.md" in content:
        return False

    # Find the best insertion point
    # Priority 1: After "## Documentation Prerequisites" section (before next ##)
    # Priority 2: After "## Dependencies & Concurrency" section
    # Priority 3: After the first line (title)

    lines = content.split("\n")
    insert_index = None

    # Look for Documentation Prerequisites section
    for i, line in enumerate(lines):
        if line.strip().startswith("## Documentation Prerequisites"):
            # Find the next section header or end of list
            for j in range(i + 1, len(lines)):
                if lines[j].strip().startswith("## "):
                    insert_index = j
                    break
                elif lines[j].strip() == "" and j + 1 < len(lines) and lines[j + 1].strip().startswith("## "):
                    insert_index = j + 1
                    break
            if insert_index is None:
                # No next section found, insert after last non-empty line in prerequisites
                for j in range(i + 1, len(lines)):
                    if lines[j].strip().startswith("## "):
                        insert_index = j
                        break
            break

    # Fallback: after Dependencies & Concurrency
    if insert_index is None:
        for i, line in enumerate(lines):
            if line.strip().startswith("## Dependencies"):
                for j in range(i + 1, len(lines)):
                    if lines[j].strip().startswith("## "):
                        insert_index = j
                        break
                break

    # Fallback: after first heading
    if insert_index is None:
        for i, line in enumerate(lines):
            if line.strip().startswith("# "):
                insert_index = i + 2  # After title and blank line
                break

    # Final fallback: beginning of file
    if insert_index is None:
        insert_index = 1

    # Insert the reference
    new_lines = lines[:insert_index] + [reference_line.strip(), ""] + lines[insert_index:]
    new_content = "\n".join(new_lines)

    filepath.write_text(new_content, encoding="utf-8")
    return True


def main():
    modified = 0
    skipped = 0

    # Process implplan directory
    print("Processing docs/implplan...")
    for filepath in sorted(IMPLPLAN_DIR.glob("SPRINT_*.md")):
        if add_reference_to_sprint(filepath, REFERENCE_LINE_IMPLPLAN):
            print(f"Modified: {filepath.name}")
            modified += 1
        else:
            print(f"Skipped: {filepath.name}")
            skipped += 1

    # Process router directory
    print("\nProcessing docs/router...")
    for filepath in sorted(ROUTER_DIR.glob("SPRINT_*.md")):
        if add_reference_to_sprint(filepath, REFERENCE_LINE_ROUTER):
            print(f"Modified: {filepath.name}")
            modified += 1
        else:
            print(f"Skipped: {filepath.name}")
            skipped += 1

    print(f"\nSummary: {modified} files modified, {skipped} files skipped")


if __name__ == "__main__":
    main()