#!/usr/bin/env python3
"""
Utilities for generating unified diffs from Edit tool operations.
"""

import difflib
from typing import Dict, Any


def generate_unified_diff(old_string: str, new_string: str, file_path: str = "") -> str:
    """
    Generate a unified diff from old and new strings.

    Args:
        old_string: Original content
        new_string: Modified content
        file_path: Optional file path for context

    Returns:
        Unified diff string with line numbers and +/- markers
    """
    old_lines = old_string.splitlines(keepends=True)
    new_lines = new_string.splitlines(keepends=True)

    # Generate unified diff
    diff = difflib.unified_diff(
        old_lines,
        new_lines,
        fromfile=f"a/{file_path}" if file_path else "a/file",
        tofile=f"b/{file_path}" if file_path else "b/file",
        lineterm="",
    )

    return "".join(diff)


def format_edit_as_diff(tool_input: Dict[str, Any]) -> str:
    """
    Format an Edit tool's input as a syntax-highlighted diff with CSS classes.

    Args:
        tool_input: The input dict from an Edit tool_use

    Returns:
        HTML-formatted diff block with red/green highlighting
    """
    file_path = tool_input.get("file_path", "")
    old_string = tool_input.get("old_string", "")
    new_string = tool_input.get("new_string", "")
    replace_all = tool_input.get("replace_all", False)

    # Get relative path for display
    display_path = file_path
    if file_path.startswith("/"):
        # Try to shorten to just the filename and parent dir
        parts = file_path.split("/")
        if len(parts) > 2:
            display_path = "/".join(parts[-2:])

    # Generate diff
    diff_output = generate_unified_diff(old_string, new_string, display_path)

    # Build output with custom HTML wrapper for styling
    output = f"**📝 Edit File:** `{display_path}`"
    if replace_all:
        output += " _(replace all occurrences)_"
    output += "\n\n"

    # Output clean diff syntax wrapped in div for CSS targeting
    output += '<div class="code-diff">\n\n```diff\n'
    output += diff_output
    output += '\n```\n\n</div>'

    return output


def format_edit_as_inline(tool_input: Dict[str, Any]) -> str:
    """
    Format an Edit tool's input as inline before/after blocks (fallback).

    Args:
        tool_input: The input dict from an Edit tool_use

    Returns:
        Markdown-formatted before/after comparison
    """
    file_path = tool_input.get("file_path", "")
    old_string = tool_input.get("old_string", "")
    new_string = tool_input.get("new_string", "")

    display_path = file_path
    if file_path.startswith("/"):
        parts = file_path.split("/")
        if len(parts) > 2:
            display_path = "/".join(parts[-2:])

    output = f"**📝 Edit File:** `{display_path}`\n\n"
    output += "<details>\n<summary>View Changes</summary>\n\n"
    output += "**Before:**\n```\n" + old_string + "\n```\n\n"
    output += "**After:**\n```\n" + new_string + "\n```\n\n"
    output += "</details>"

    return output


def detect_language_from_path(file_path: str) -> str:
    """
    Detect programming language from file extension.

    Args:
        file_path: Path to file

    Returns:
        Language identifier for syntax highlighting
    """
    ext_map = {
        ".py": "python",
        ".js": "javascript",
        ".ts": "typescript",
        ".tsx": "tsx",
        ".jsx": "jsx",
        ".java": "java",
        ".cpp": "cpp",
        ".c": "c",
        ".h": "c",
        ".hpp": "cpp",
        ".rs": "rust",
        ".go": "go",
        ".rb": "ruby",
        ".php": "php",
        ".swift": "swift",
        ".kt": "kotlin",
        ".scala": "scala",
        ".sh": "bash",
        ".bash": "bash",
        ".zsh": "zsh",
        ".fish": "fish",
        ".ps1": "powershell",
        ".yaml": "yaml",
        ".yml": "yaml",
        ".json": "json",
        ".xml": "xml",
        ".html": "html",
        ".css": "css",
        ".scss": "scss",
        ".sass": "sass",
        ".md": "markdown",
        ".mdx": "mdx",
        ".sql": "sql",
        ".r": "r",
        ".m": "matlab",
        ".vim": "vim",
    }

    # Get extension
    for ext, lang in ext_map.items():
        if file_path.endswith(ext):
            return lang

    return ""