"use strict";

/**
 * 设备预案（双轨完整结构）CRUD + 匹配 + Review Workflow
 *
 * 详见设计方案 §1.1 双轨绑定概念 + §4.3 数据结构
 *
 * 匹配逻辑：
 *   1. filter 按 level 从高到低过滤
 *   2. scope 匹配：host_ids 精确匹配 > host_groups 匹配 > 全 scope
 *   3. match 条件：device_tiers / alert_types / metric_rules
 *   4. 同 level 下 scope 最精确者胜出（D3）
 */

const { STORAGE_KEY_DEVICE_PLANS } = require("./storageKeys.cjs");
const { PLAN_STATUS, STEP_EXECUTION } = require("./types.cjs");

let _plans = null;

function _ensureLoaded(readFn) {
  if (_plans === null) {
    const raw = readFn(STORAGE_KEY_DEVICE_PLANS);
    _plans = raw ? _safeParse(raw, []) : [];
  }
}

function _safeParse(text, def) {
  if (text === null || text === undefined) return def;
  if (typeof text === "object") return text;
  try { return JSON.parse(text); }
  catch { return def; }
}

function _save(writeFn) {
  writeFn(STORAGE_KEY_DEVICE_PLANS, JSON.stringify(_plans));
}

// ---------- CRUD ----------

function listPlans(readFn, filters = {}) {
  _ensureLoaded(readFn);
  let result = [..._plans];
  if (filters.status) result = result.filter((p) => p.status === filters.status);
  if (filters.device_type) result = result.filter((p) => p.device_type === filters.device_type);
  if (filters.level) result = result.filter((p) => p.level === filters.level);
  if (filters.enabled !== undefined) result = result.filter((p) => p.enabled === filters.enabled);
  return result.sort((a, b) => (b.updated_at || 0) - (a.updated_at || 0));
}

function getPlan(readFn, planId) {
  _ensureLoaded(readFn);
  return _plans.find((p) => p.id === planId) || null;
}

function createPlan(readFn, writeFn, data) {
  _ensureLoaded(readFn);
  const now = Date.now();
  const plan = {
    id: data.id || `plan_${now}_${Math.random().toString(36).slice(2, 8)}`,
    template_id: data.template_id || null,
    device_type: data.device_type,
    level: data.level || "warning",
    enabled: data.enabled !== false,
    builtin: !!data.builtin,
    status: data.status || PLAN_STATUS.ACTIVE,
    source: data.source || "manual",
    ai_provider: data.ai_provider || null,
    ai_prompt_version: data.ai_prompt_version || null,
    reject_reason: data.reject_reason || null,
    review_log: data.review_log || [],
    description: data.description || "",
    // 匹配元数据
    match: data.match || { metric_rules: [], alert_types: [], device_tiers: [], device_tags: [] },
    scope: data.scope || { host_ids: [], host_groups: [] },
    // 双轨预案
    human_action_guide: data.human_action_guide || _emptyHumanActionGuide(),
    remediation: data.remediation || { steps: [] },
    // 安全权限
    security: data.security || { allowed_command_ids: [], allowed_commands: [], blocked_patterns: [] },
    required_role: data.required_role || "operator",
    escalation_fallback: data.escalation_fallback || null,
    created_at: now,
    updated_at: now,
  };
  _plans.push(plan);
  _save(writeFn);
  return { ...plan };
}

function updatePlan(readFn, writeFn, planId, updates) {
  _ensureLoaded(readFn);
  const idx = _plans.findIndex((p) => p.id === planId);
  if (idx === -1) return null;
  _plans[idx] = { ..._plans[idx], ...updates, updated_at: Date.now() };
  _save(writeFn);
  return { ..._plans[idx] };
}

function deletePlan(readFn, writeFn, planId) {
  _ensureLoaded(readFn);
  const idx = _plans.findIndex((p) => p.id === planId);
  if (idx === -1) return false;
  if (_plans[idx].builtin) return false;
  _plans.splice(idx, 1);
  _save(writeFn);
  return true;
}

function togglePlan(readFn, writeFn, planId, enabled) {
  return updatePlan(readFn, writeFn, planId, { enabled });
}

// ---------- Review Workflow（D13）----------

function approvePlan(readFn, writeFn, planId, actor = "admin") {
  _ensureLoaded(readFn);
  const idx = _plans.findIndex((p) => p.id === planId);
  if (idx === -1) return null;
  const now = Date.now();
  const reviewLog = [...(_plans[idx].review_log || []), { ts: now, actor, action: "approve", reason: null }];
  _plans[idx] = {
    ..._plans[idx],
    status: PLAN_STATUS.ACTIVE,
    reject_reason: null,
    review_log: reviewLog,
    updated_at: now,
  };
  _save(writeFn);
  return { ..._plans[idx] };
}

function rejectPlan(readFn, writeFn, planId, reason, actor = "admin") {
  _ensureLoaded(readFn);
  const idx = _plans.findIndex((p) => p.id === planId);
  if (idx === -1) return null;
  const now = Date.now();
  const reviewLog = [...(_plans[idx].review_log || []), { ts: now, actor, action: "reject", reason }];
  _plans[idx] = {
    ..._plans[idx],
    status: PLAN_STATUS.DRAFT,
    reject_reason: reason,
    review_log: reviewLog,
    updated_at: now,
  };
  _save(writeFn);
  return { ..._plans[idx] };
}

// ---------- 匹配逻辑（D3：同 level 下 scope 最精确者胜出）----------

/**
 * 匹配预案：给一条新告警找最优预案
 * @param {object} readFn - 存储读取函数
 * @param {object} alert - 告警记录（含 device_id, device_name, metric, level, alert_type）
 * @param {object} deviceProfile - 设备画像（catalog_id, tier, group, tags, host_id）
 * @returns {object|null} 匹配结果 { plan, score } 或 null
 */
function matchPlan(readFn, alert, deviceProfile) {
  _ensureLoaded(readFn);

  const deviceType = deviceProfile?.catalog_id || alert.device_catalog || "";
  const deviceTier = deviceProfile?.tier || "";
  const alertLevel = alert.level;
  const alertType = alert.alert_type || _inferAlertType(alert.metric);
  const hostId = deviceProfile?.host_id || alert.device_id;

  // 1. 筛选：只看 enabled + active 的预案（跳过 draft）
  const candidates = _plans.filter((p) =>
    p.enabled &&
    p.status === PLAN_STATUS.ACTIVE &&
    (!p.device_type || p.device_type === deviceType || p.device_type === "any") &&
    (!alertLevel || p.level === alertLevel || p.level === "info") // info 级预案兜底
  );

  if (candidates.length === 0) return null;

  // 2. 评分：scope 越精确分越高
  let best = null;
  for (const plan of candidates) {
    const score = _computeMatchScore(plan, { hostId, deviceTier, alertType, alertLevel });
    if (score > 0 && (!best || score > best.score)) {
      best = { plan, score };
    }
  }

  return best;
}

function _computeMatchScore(plan, ctx) {
  let score = 10; // 基础分

  // scope 匹配：host_ids > host_groups > 全 scope
  if (plan.scope?.host_ids?.includes(ctx.hostId)) score += 100;        // 精确设备
  else if (plan.scope?.host_groups?.length > 0) score += 50;           // 分组
  else score += 10;                                                     // 全 scope

  // match.device_tiers
  if (plan.match?.device_tiers?.length > 0 && plan.match.device_tiers.includes(ctx.deviceTier)) score += 30;

  // match.alert_types
  if (plan.match?.alert_types?.length > 0 && plan.match.alert_types.includes(ctx.alertType)) score += 20;

  return score;
}

function _inferAlertType(metric) {
  if (!metric) return "performance_high";
  if (/offline|online|connect|reachable/i.test(metric)) return "connectivity";
  if (/temperature|power|fan/i.test(metric)) return "connectivity";
  if (/security|intrusion|firewall/i.test(metric)) return "security";
  return "performance_high";
}

// ---------- 完整性检查（D16：human_action ↔ remediation 映射）----------

function validateHumanActionRemediationMapping(plan) {
  const warnings = [];
  if (!plan?.human_action_guide || !plan?.remediation?.steps) return { valid: true, warnings };

  const stepCommandIds = plan.remediation.steps
    .filter((s) => s.action === "command")
    .map((s) => s.command_id)
    .filter(Boolean);

  const infoGathering = plan.human_action_guide.info_gathering || [];
  for (const entry of infoGathering) {
    if (!stepCommandIds.some((id) => entry.action?.includes(id.split("_").pop()) || stepCommandIds.length > 0)) {
      // 宽松检查：只要 remediation 有至少一个 auto/confirm step 就算 OK
    }
  }

  // 严格检查：info_gathering 条数 vs remediation auto+confirm steps 条数
  const autoConfirmSteps = plan.remediation.steps.filter((s) =>
    s.execution === STEP_EXECUTION.AUTO || s.execution === STEP_EXECUTION.CONFIRM
  );
  if (infoGathering.length > 0 && autoConfirmSteps.length < infoGathering.length) {
    warnings.push(`human_action_guide.info_gathering 有 ${infoGathering.length} 条，但 remediation 只有 ${autoConfirmSteps.length} 个 auto/confirm step（可能缺失处置步骤）`);
  }

  return { valid: warnings.length === 0, warnings };
}

function _emptyHumanActionGuide() {
  return {
    receiving_alerts: [],
    info_gathering: [],
    notification_chain: [],
    escalation_triggers: [],
    pre_remediation: [],
    post_remediation: [],
  };
}

function _resetForTest() { _plans = null; }

module.exports = {
  listPlans,
  getPlan,
  createPlan,
  updatePlan,
  deletePlan,
  togglePlan,
  approvePlan,
  rejectPlan,
  matchPlan,
  validateHumanActionRemediationMapping,
  _resetForTest,
};