"""代码差异对比命令：diff。"""
from __future__ import annotations

import argparse
import difflib
import logging
import os

from sapcli.client import ADTClient
from sapcli.types import get_type_config, parse_object_name

logger = logging.getLogger("sapcli.commands.diff_cmd")


def cmd_diff(args: argparse.Namespace, client: ADTClient) -> None:
    """本地 vs SAP 代码差异对比。"""
    name: str = args.name
    obj_type: str = args.type
    local_path: str | None = getattr(args, "path", None)

    parsed = parse_object_name(name, obj_type)
    type_label = get_type_config(obj_type).label

    if parsed.src_uri is None:
        print(f"\n  ✗ {type_label}没有源代码，不支持 diff 操作")
        return

    print("=" * 60)
    print("  SAP ADT 代码差异对比")
    print("=" * 60)
    print(f"  对象名称: {parsed.display_name}")
    print(f"  对象类型: {type_label}")

    # 读取本地文件
    if local_path is None:
        # 尝试自动推断文件路径
        local_path = f"{parsed.file_base}.abap"
    if not os.path.isfile(local_path):
        print(f"\n  ✗ 本地文件不存在: {local_path}")
        return

    with open(local_path, "r", encoding="utf-8") as f:
        local_source = f.read()

    local_lines = local_source.splitlines(keepends=True)
    print(f"  本地文件: {local_path} ({len(local_lines)} 行)")

    # 读取 SAP 端源码
    print(f"\n  → 正在读取 SAP 端源码...")
    try:
        sap_source = client.read_source_for_diff(name, obj_type)
    except Exception as e:
        print(f"  ✗ 读取 SAP 源码失败: {e}")
        return

    sap_source = sap_source.replace("\r\n", "\n").replace("\r", "\n")
    sap_lines = sap_source.splitlines(keepends=True)
    print(f"  ✓ SAP 源码读取成功 ({len(sap_lines)} 行)")

    # 生成 unified diff
    diff_lines = list(difflib.unified_diff(
        sap_lines,
        local_lines,
        fromfile=f"SAP:{parsed.display_name}",
        tofile=f"本地:{os.path.basename(local_path)}",
        lineterm="",
    ))

    if not diff_lines:
        print(f"\n  ✓ 本地文件与 SAP 端完全一致，无差异")
        return

    print(f"\n  {'─' * 60}")
    print(f"  差异摘要:")
    added = sum(1 for l in diff_lines if l.startswith("+") and not l.startswith("+++"))
    removed = sum(1 for l in diff_lines if l.startswith("-") and not l.startswith("---"))
    print(f"    新增行: {added} | 删除行: {removed}")
    print(f"  {'─' * 60}\n")

    # 输出 diff
    for line in diff_lines:
        if line.startswith("+") and not line.startswith("+++"):
            print(f"  \033[32m{line}\033[0m")
        elif line.startswith("-") and not line.startswith("---"):
            print(f"  \033[31m{line}\033[0m")
        elif line.startswith("@@"):
            print(f"  \033[36m{line}\033[0m")
        else:
            print(f"  {line}")