# -*- coding: utf-8 -*-
"""性能预算与懒加载策略冒烟脚本（Issue #54）。

直接运行 ``python _sanity_check.py`` 验证：默认预算可构造、校验器对达标/超预算
场景给出正确状态、懒加载决策器对视口内外 widget 给出 immediate/idle。零第三方依赖。
"""
import importlib.util
import os
import sys

# perf-budget 目录名含连字符，按文件路径加载为合法包 perf_budget。
_PKG_DIR = os.path.dirname(os.path.abspath(__file__))


def _load_pkg(name, path):
    if name in sys.modules:
        return
    spec = importlib.util.spec_from_file_location(
        name, os.path.join(path, "__init__.py"),
        submodule_search_locations=[path])
    mod = importlib.util.module_from_spec(spec)
    sys.modules[name] = mod
    spec.loader.exec_module(mod)


_load_pkg("perf_budget", _PKG_DIR)

from perf_budget import (  # noqa: E402
    BudgetStatus, BudgetVerifier, LazyLoadPlanner, PerformanceBudget,
    ResourceMeasurement, ResourceType, WidgetLayout)


def main() -> int:
    # 1) 性能预算：达标场景
    budget = PerformanceBudget.default_cockpit()
    report = BudgetVerifier(budget).verify([
        ResourceMeasurement("app.js", ResourceType.JS, 700, block_render=True),
        ResourceMeasurement("app.css", ResourceType.CSS, 250, block_render=True),
        ResourceMeasurement("doc.html", ResourceType.HTML, 150, block_render=True),
    ])
    assert report.status is BudgetStatus.PASS, report.reason
    print(f"[OK] 性能预算达标：首屏 {report.first_paint_ms:.0f}ms "
          f"≤ {report.budget_ms:.0f}ms（{report.reason}）")

    # 2) 超预算场景
    bad = BudgetVerifier(budget).verify([
        ResourceMeasurement("big.js", ResourceType.JS, 950, block_render=True),
    ])
    assert bad.status is BudgetStatus.FAIL
    print(f"[OK] 性能预算告警：{bad.overrun[0].reason} → {bad.overrun[0].advice}")

    # 3) 懒加载：视口内外分流
    plan = LazyLoadPlanner().plan([
        WidgetLayout("proc", "process_view", y=0, h=4, always_load=True),
        WidgetLayout("trend", "trend", y=10, h=2),
    ], scroll_y_rows=0)
    assert plan.immediate_ids == ["proc"]
    assert plan.idle_ids == ["trend"]
    print(f"[OK] 懒加载：immediate={plan.immediate_ids} idle={plan.idle_ids}")
    print("性能预算与懒加载策略冒烟通过 ✅")
    return 0


if __name__ == "__main__":
    raise SystemExit(main())