import { z } from "zod";
import { Id, Timestamp } from "./common";

// 全局设置:存于 settings 表(key → jsonb)。每个顶层分组对应一个 settings.key。
// schema 本身不带 .default()(zod 4 在 partial 里仍会套默认值,会让 PATCH 覆盖现值);
// 缺省值统一放在 DEFAULT_SETTINGS,服务端读取时 `{ ...DEFAULT_SETTINGS[key], ...stored }` 后再 parse。

const Percent = z.number().min(1).max(100);

export const AutomationSettings = z.object({
  /** 自动化总开关:关闭后所有自动收录/下载/整理停止,只读查询与手动操作可用 */
  enabled: z.boolean(),
  /** 恢复后的只读对账模式(REQ §8.5):开启时禁止自动写入 */
  readOnlyReconcile: z.boolean(),
});
export type AutomationSettings = z.infer<typeof AutomationSettings>;

const CacheShape = z.object({
  /** 缓存卷使用率硬阈值:达到即停止新增下载并暂停纳管下载中任务 */
  hardThresholdPercent: Percent,
  /** 恢复水位:降到此值以下恢复因阈值暂停的任务 */
  resumePercent: Percent,
  checkIntervalSec: z.number().int().min(10).max(3600),
  /** 缓存清理的目标使用率(低水位) */
  cleanupTargetPercent: Percent,
});
/** 下载缓存卷硬阈值与恢复水位(REQ §8.4.1) */
export const CacheSettings = CacheShape.refine((v) => v.resumePercent < v.hardThresholdPercent, {
  message: "恢复水位必须低于硬阈值",
}).refine((v) => v.cleanupTargetPercent <= v.resumePercent, { message: "清理目标不得高于恢复水位" });
export type CacheSettings = z.infer<typeof CacheSettings>;

export const OrganizeMode = z.enum(["copy", "move"]);
export type OrganizeMode = z.infer<typeof OrganizeMode>;
export const OrganizeSettings = z.object({
  defaultMode: OrganizeMode,
  /** 跨卷 Move 采用 Copy→核验→删源;EXDEV 不静默降级 */
  allowCrossVolumeMove: z.boolean(),
});
export type OrganizeSettings = z.infer<typeof OrganizeSettings>;

export const RetentionSettings = z.object({
  /** Copy 入库后下载源在缓存中至少保留的天数(与 H&R 要求分开判断) */
  seedRetentionDays: z.number().int().min(0).max(365),
  /** 观察/日志类数据保留天数 */
  logRetentionDays: z.number().int().min(1).max(3650),
});
export type RetentionSettings = z.infer<typeof RetentionSettings>;

export const ThinkingLevel = z.enum(["off", "minimal", "low", "medium", "high", "xhigh"]);
export type ThinkingLevel = z.infer<typeof ThinkingLevel>;

/** Pi Agent 设置(REQ §10.5):上游/模型/思考档位/上下文预算/压缩/子代理;密钥只存 secret 引用 */
export const PiSettings = z.object({
  provider: z.string().min(1),
  baseUrl: z.url().nullable(),
  model: z.string().min(1).nullable(),
  thinkingLevel: ThinkingLevel,
  /** 上下文预算(token) */
  contextBudget: z.number().int().min(4096).max(2_000_000),
  compaction: z.object({
    enabled: z.boolean(),
    /** 达到上下文预算的该比例时触发压缩 */
    thresholdRatio: z.number().min(0.3).max(0.95),
  }),
  subagentsEnabled: z.boolean(),
  apiKeySecretRef: Id.nullable(),
});
export type PiSettings = z.infer<typeof PiSettings>;

/** 每日预算与并发(REQ §6.4、§10.5) */
export const BudgetSettings = z.object({
  maxNewTitlesPerDay: z.number().int().min(0),
  maxDownloadBytesPerDay: z.number().int().min(0),
  maxConcurrentDownloads: z.number().int().min(1).max(100),
  agentMaxRunsPerDay: z.number().int().min(0),
  agentMaxCostUsdPerDay: z.number().min(0),
});
export type BudgetSettings = z.infer<typeof BudgetSettings>;

export const GlobalSettings = z.object({
  automation: AutomationSettings,
  cache: CacheSettings,
  organize: OrganizeSettings,
  retention: RetentionSettings,
  pi: PiSettings,
  budget: BudgetSettings,
});
export type GlobalSettings = z.infer<typeof GlobalSettings>;

/** settings 表的合法 key */
export const SettingsKey = GlobalSettings.keyof();
export type SettingsKey = z.infer<typeof SettingsKey>;

/** 缺省设置(settings 表缺 key 或缺字段时使用) */
export const DEFAULT_SETTINGS: GlobalSettings = {
  automation: { enabled: true, readOnlyReconcile: false },
  cache: { hardThresholdPercent: 90, resumePercent: 85, checkIntervalSec: 60, cleanupTargetPercent: 80 },
  organize: { defaultMode: "copy", allowCrossVolumeMove: true },
  retention: { seedRetentionDays: 7, logRetentionDays: 180 },
  pi: {
    provider: "anthropic",
    baseUrl: null,
    model: null,
    thinkingLevel: "medium",
    contextBudget: 128_000,
    compaction: { enabled: true, thresholdRatio: 0.8 },
    subagentsEnabled: false,
    apiKeySecretRef: null,
  },
  budget: {
    maxNewTitlesPerDay: 20,
    maxDownloadBytesPerDay: 500 * 1024 ** 3,
    maxConcurrentDownloads: 5,
    agentMaxRunsPerDay: 50,
    agentMaxCostUsdPerDay: 5,
  },
};

/** PATCH /settings:按分组部分更新;服务端与现值合并后用 GlobalSettings 整体再校验 */
export const GlobalSettingsUpdate = z.object({
  automation: AutomationSettings.partial().optional(),
  cache: CacheShape.partial().optional(),
  organize: OrganizeSettings.partial().optional(),
  retention: RetentionSettings.partial().optional(),
  pi: PiSettings.omit({ apiKeySecretRef: true })
    .partial()
    .extend({
      compaction: PiSettings.shape.compaction.partial().optional(),
      /** 只写:明文上游密钥,服务端存为 secret 并回填 apiKeySecretRef;传 null 表示清除 */
      apiKey: z.string().min(1).max(4096).nullable().optional(),
    })
    .optional(),
  budget: BudgetSettings.partial().optional(),
});
export type GlobalSettingsUpdate = z.infer<typeof GlobalSettingsUpdate>;

/** 合并部分更新(纯函数,web 乐观更新与 server 共用) */
export function mergeSettings(current: GlobalSettings, patch: GlobalSettingsUpdate): GlobalSettings {
  const { apiKey: _apiKey, compaction, ...pi } = patch.pi ?? {};
  return {
    automation: { ...current.automation, ...patch.automation },
    cache: { ...current.cache, ...patch.cache },
    organize: { ...current.organize, ...patch.organize },
    retention: { ...current.retention, ...patch.retention },
    pi: { ...current.pi, ...pi, compaction: { ...current.pi.compaction, ...compaction } },
    budget: { ...current.budget, ...patch.budget },
  };
}

/** settings 表行 */
export const SettingEntry = z.object({
  key: SettingsKey,
  value: z.unknown(),
  updatedAt: Timestamp,
});
export type SettingEntry = z.infer<typeof SettingEntry>;