# YAML/JSON 差异对比工具

import yaml


def compute_diff(doc_a: dict | str, doc_b: dict | str) -> dict:
    """Compute diff between two dicts or YAML strings."""
    if isinstance(doc_a, str):
        try:
            doc_a = yaml.safe_load(doc_a) or {}
        except yaml.YAMLError:
            doc_a = {}
    if isinstance(doc_b, str):
        try:
            doc_b = yaml.safe_load(doc_b) or {}
        except yaml.YAMLError:
            doc_b = {}

    added, removed, modified = _recursive_diff(doc_a, doc_b, "")
    return {
        "added": added,
        "removed": removed,
        "modified": modified,
    }


def _recursive_diff(a: dict | list, b: dict | list, path: str) -> tuple[list, list, list]:
    added, removed, modified = [], [], []

    if isinstance(a, dict) and isinstance(b, dict):
        all_keys = set(a.keys()) | set(b.keys())
        for key in sorted(all_keys):
            new_path = f"{path}.{key}" if path else key
            if key not in a:
                added.append({"path": new_path, "value": b[key]})
            elif key not in b:
                removed.append({"path": new_path, "value": a[key]})
            elif a[key] != b[key]:
                if isinstance(a[key], (dict, list)) and isinstance(b[key], (dict, list)):
                    a_sub, r_sub, m_sub = _recursive_diff(a[key], b[key], new_path)
                    added.extend(a_sub)
                    removed.extend(r_sub)
                    modified.extend(m_sub)
                else:
                    modified.append({
                        "path": new_path,
                        "old_value": a[key],
                        "new_value": b[key],
                    })

    elif isinstance(a, list) and isinstance(b, list):
        for i in range(max(len(a), len(b))):
            new_path = f"{path}[{i}]"
            if i >= len(a):
                added.append({"path": new_path, "value": b[i]})
            elif i >= len(b):
                removed.append({"path": new_path, "value": a[i]})
            elif a[i] != b[i]:
                if isinstance(a[i], (dict, list)) and isinstance(b[i], (dict, list)):
                    a_sub, r_sub, m_sub = _recursive_diff(a[i], b[i], new_path)
                    added.extend(a_sub)
                    removed.extend(r_sub)
                    modified.extend(m_sub)
                else:
                    modified.append({
                        "path": new_path,
                        "old_value": a[i],
                        "new_value": b[i],
                    })

    return added, removed, modified