const CONFIG_TABLE = 'h5_agent_code_run_config';
const CONFIG_SCOPE = 'global';
const POLICY_SOURCE_ENV = 'env';
const POLICY_SOURCE_ENV_OVERRIDE = 'env-override';
const POLICY_SOURCE_ENV_MIGRATION = 'env-migration';
const POLICY_SOURCE_ADMIN_DB = 'admin-db';
const POLICY_SOURCE_DEFAULT = 'default';

const DEFAULT_TASK_TYPES = Object.freeze([
  'page_data_dev',
  'page_data_dev_complex',
  'h5_chat_code_task',
  'page_edit_code_task',
]);

function defaultConfigShape() {
  return {
    codeRun: {
      enabled: false,
      clientEnabled: false,
      generalAutodetect: false,
      requireValidation: true,
      userAllowlist: [],
      taskTypeAllowlist: [...DEFAULT_TASK_TYPES],
    },
    pageDataDev: {
      autodetect: false,
    },
    meta: {
      notes: '',
    },
  };
}

function envFlag(value, fallback = false) {
  const raw = String(value ?? '').trim().toLowerCase();
  if (!raw) return fallback;
  return ['1', 'true', 'yes', 'on'].includes(raw);
}

function normalizeBoolean(value, fallback = false) {
  if (value == null || value === '') return fallback;
  if (typeof value === 'boolean') return value;
  const normalized = String(value).trim().toLowerCase();
  if (['1', 'true', 'yes', 'on'].includes(normalized)) return true;
  if (['0', 'false', 'no', 'off'].includes(normalized)) return false;
  return fallback;
}

function normalizeStringList(value) {
  if (!Array.isArray(value)) {
    return String(value ?? '')
      .split(',')
      .map((item) => item.trim())
      .filter(Boolean);
  }
  return value.map((item) => String(item ?? '').trim()).filter(Boolean);
}

function cloneConfig(config = null) {
  return structuredClone?.(config ?? defaultConfigShape())
    ?? JSON.parse(JSON.stringify(config ?? defaultConfigShape()));
}

function parseJsonLike(value, fallback) {
  if (value == null || value === '') return fallback;
  if (typeof value === 'string') {
    try {
      return JSON.parse(value);
    } catch {
      return fallback;
    }
  }
  if (typeof value === 'object') return value;
  return fallback;
}

function policySourceFromEnv(env = process.env) {
  return String(env.MEMIND_CODE_RUN_POLICY_SOURCE ?? '').trim().toLowerCase() === 'env'
    ? POLICY_SOURCE_ENV_OVERRIDE
    : null;
}

function buildConfigFromEnv(env = process.env) {
  const config = defaultConfigShape();
  config.codeRun.enabled = envFlag(env.MEMIND_AGENT_CODE_RUNS_ENABLED);
  config.codeRun.clientEnabled = envFlag(env.VITE_AGENT_CODE_RUNS_ENABLED, config.codeRun.enabled);
  config.codeRun.generalAutodetect = envFlag(env.VITE_AGENT_CODE_RUNS_AUTODETECT);
  config.codeRun.requireValidation = envFlag(env.MEMIND_AGENT_CODE_RUNS_REQUIRE_VALIDATION, true);
  config.codeRun.userAllowlist = normalizeStringList(env.MEMIND_AGENT_CODE_RUNS_USER_IDS);
  const taskTypes = normalizeStringList(env.MEMIND_AGENT_CODE_RUN_TASK_TYPES);
  config.codeRun.taskTypeAllowlist = taskTypes.length ? taskTypes : [...DEFAULT_TASK_TYPES];
  config.pageDataDev.autodetect = envFlag(env.VITE_AGENT_PAGE_DATA_DEV_AUTODETECT);
  return config;
}

function envPolicyActive(config) {
  return Boolean(config?.codeRun?.enabled)
    || Boolean(config?.codeRun?.clientEnabled)
    || Boolean(config?.pageDataDev?.autodetect)
    || (config?.codeRun?.userAllowlist?.length ?? 0) > 0;
}

function mergePatch(currentConfig, patch = {}) {
  const next = cloneConfig(currentConfig);
  const codeRunPatch = patch?.codeRun ?? {};
  const pageDataDevPatch = patch?.pageDataDev ?? {};

  if ('enabled' in codeRunPatch) next.codeRun.enabled = normalizeBoolean(codeRunPatch.enabled, false);
  if ('clientEnabled' in codeRunPatch) {
    next.codeRun.clientEnabled = normalizeBoolean(codeRunPatch.clientEnabled, false);
  }
  if ('generalAutodetect' in codeRunPatch) {
    next.codeRun.generalAutodetect = normalizeBoolean(codeRunPatch.generalAutodetect, false);
  }
  if ('requireValidation' in codeRunPatch) {
    next.codeRun.requireValidation = normalizeBoolean(codeRunPatch.requireValidation, true);
  }
  if ('userAllowlist' in codeRunPatch) {
    next.codeRun.userAllowlist = normalizeStringList(codeRunPatch.userAllowlist);
  }
  if ('taskTypeAllowlist' in codeRunPatch) {
    const taskTypes = normalizeStringList(codeRunPatch.taskTypeAllowlist);
    next.codeRun.taskTypeAllowlist = taskTypes.length ? taskTypes : [...DEFAULT_TASK_TYPES];
  }
  if ('autodetect' in pageDataDevPatch) {
    next.pageDataDev.autodetect = normalizeBoolean(pageDataDevPatch.autodetect, false);
  }
  if (patch?.meta && typeof patch.meta.notes === 'string') {
    next.meta.notes = patch.meta.notes;
  }
  return next;
}

function flattenPolicy(config, source) {
  const taskTypeAllowlist = normalizeStringList(config.codeRun.taskTypeAllowlist);
  return {
    source,
    enabled: Boolean(config.codeRun.enabled),
    clientEnabled: Boolean(config.codeRun.clientEnabled),
    generalAutodetect: Boolean(config.codeRun.generalAutodetect),
    requireValidation: Boolean(config.codeRun.requireValidation),
    pageDataDevAutodetect: Boolean(config.pageDataDev.autodetect),
    userAllowlist: normalizeStringList(config.codeRun.userAllowlist),
    taskTypeAllowlist: taskTypeAllowlist.length ? taskTypeAllowlist : [...DEFAULT_TASK_TYPES],
  };
}

export function isUserAllowedByCodeRunPolicy(userId, policy) {
  if (!policy?.enabled) return false;
  const allowlist = policy.userAllowlist ?? [];
  if (allowlist.length === 0) return true;
  return allowlist.includes(String(userId ?? '').trim());
}

export function isTaskTypeAllowedByCodeRunPolicy(taskType, policy) {
  const allowlist = (policy?.taskTypeAllowlist ?? []).map((item) => String(item).toLowerCase());
  if (allowlist.length === 0) return true;
  const normalized = String(taskType ?? '').trim().toLowerCase();
  if (!normalized) return false;
  return allowlist.includes(normalized);
}

async function ensureConfigTable(pool) {
  await pool.query(`
    CREATE TABLE IF NOT EXISTS ${CONFIG_TABLE} (
      config_scope VARCHAR(32) PRIMARY KEY,
      config_json JSON NOT NULL,
      updated_by CHAR(36) NULL,
      updated_at BIGINT NOT NULL
    ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci
  `);
}

async function loadStoredState(pool) {
  await ensureConfigTable(pool);
  const [rows] = await pool.query(
    `SELECT config_json, updated_by, updated_at
       FROM ${CONFIG_TABLE}
      WHERE config_scope = ?
      LIMIT 1`,
    [CONFIG_SCOPE],
  );
  const row = rows[0];
  if (!row) return null;
  const parsed = parseJsonLike(row.config_json, {});
  return {
    config: mergePatch(defaultConfigShape(), parsed),
    updatedAt: Number(row.updated_at ?? 0) || null,
    updatedBy: row.updated_by ?? null,
  };
}

export function createAgentCodeRunAdminConfigService(pool, { env = process.env } = {}) {
  async function loadEffectiveConfig() {
    const forcedEnvSource = policySourceFromEnv(env);
    if (forcedEnvSource) {
      const config = buildConfigFromEnv(env);
      return {
        config,
        updatedAt: null,
        updatedBy: null,
        source: forcedEnvSource,
      };
    }

    const stored = await loadStoredState(pool);
    if (stored) {
      return {
        config: cloneConfig(stored.config),
        updatedAt: stored.updatedAt,
        updatedBy: stored.updatedBy,
        source: POLICY_SOURCE_ADMIN_DB,
      };
    }

    const envConfig = buildConfigFromEnv(env);
    if (envPolicyActive(envConfig)) {
      return {
        config: envConfig,
        updatedAt: null,
        updatedBy: null,
        source: POLICY_SOURCE_ENV_MIGRATION,
      };
    }

    return {
      config: defaultConfigShape(),
      updatedAt: null,
      updatedBy: null,
      source: POLICY_SOURCE_DEFAULT,
    };
  }

  return {
    async getAdminConfig() {
      const state = await loadEffectiveConfig();
      return {
        config: state.config,
        updatedAt: state.updatedAt,
        updatedBy: state.updatedBy,
        source: state.source,
        envOverrideActive: state.source === POLICY_SOURCE_ENV_OVERRIDE,
      };
    },

    async updateAdminConfig(patch = {}, { updatedBy = null } = {}) {
      if (policySourceFromEnv(env)) {
        throw Object.assign(new Error('MEMIND_CODE_RUN_POLICY_SOURCE=env 时不允许通过后台修改'), {
          code: 'CODE_RUN_POLICY_ENV_LOCKED',
        });
      }
      const stored = await loadStoredState(pool);
      const base = stored?.config ?? defaultConfigShape();
      const nextConfig = mergePatch(base, patch.config ?? patch);
      await ensureConfigTable(pool);
      const now = Date.now();
      await pool.query(
        `INSERT INTO ${CONFIG_TABLE}
          (config_scope, config_json, updated_by, updated_at)
         VALUES (?, ?, ?, ?)
         ON DUPLICATE KEY UPDATE
          config_json = VALUES(config_json),
          updated_by = VALUES(updated_by),
          updated_at = VALUES(updated_at)`,
        [CONFIG_SCOPE, JSON.stringify(nextConfig), updatedBy, now],
      );
      return this.getAdminConfig();
    },

    async getRuntimeState() {
      const state = await loadEffectiveConfig();
      const policy = flattenPolicy(state.config, state.source);
      return {
        source: state.source,
        updatedAt: state.updatedAt,
        updatedBy: state.updatedBy,
        config: state.config,
        policy,
        envOverrideActive: state.source === POLICY_SOURCE_ENV_OVERRIDE,
      };
    },

    async getEffectivePolicy(userId) {
      const state = await loadEffectiveConfig();
      const policy = flattenPolicy(state.config, state.source);
      return {
        ...policy,
        userAllowed: isUserAllowedByCodeRunPolicy(userId, policy),
      };
    },

    async getPublicClientPolicy(userId) {
      const policy = await this.getEffectivePolicy(userId);
      const enabled = policy.enabled && policy.clientEnabled && policy.userAllowed;
      return {
        codeRun: {
          enabled,
          pageDataDevAutodetect: enabled && policy.pageDataDevAutodetect,
          generalAutodetect: enabled && policy.generalAutodetect,
        },
      };
    },

    async getRuntimeStatusSummary() {
      const state = await loadEffectiveConfig();
      const policy = flattenPolicy(state.config, state.source);
      return {
        source: policy.source,
        enabled: policy.enabled,
        clientEnabled: policy.clientEnabled,
        userAllowlist: policy.userAllowlist,
        taskTypeAllowlist: policy.taskTypeAllowlist,
        requireValidation: policy.requireValidation,
        pageDataDevAutodetect: policy.pageDataDevAutodetect,
        generalAutodetect: policy.generalAutodetect,
        envOverrideActive: policy.source === POLICY_SOURCE_ENV_OVERRIDE,
        updatedAt: state.updatedAt,
        updatedBy: state.updatedBy,
      };
    },

    async listRecentPageDataDevRuns({ limit = 50 } = {}) {
      const pageDataTaskTypes = new Set(['page_data_dev', 'page_data_dev_complex']);
      const capped = Math.min(Math.max(Number(limit) || 50, 1), 200);
      const [rows] = await pool.query(
        `SELECT id, user_id, request_id, status, error_message, created_at, updated_at, user_message_json
           FROM h5_agent_runs
          ORDER BY updated_at DESC
          LIMIT ?`,
        [capped * 4],
      );
      const runs = [];
      for (const row of rows) {
        if (runs.length >= capped) break;
        const parsed = parseJsonLike(row.user_message_json, {});
        const metadata = parsed?.metadata ?? {};
        const runMetadata = metadata.memindRun ?? metadata.agentRun ?? {};
        const taskType = String(runMetadata.taskType ?? metadata.taskType ?? '').trim().toLowerCase();
        if (!pageDataTaskTypes.has(taskType)) continue;
        runs.push({
          id: row.id,
          userId: row.user_id,
          requestId: row.request_id,
          status: row.status,
          taskType,
          executor: String(runMetadata.executor ?? metadata.executor ?? '').trim() || null,
          errorMessage: row.error_message ?? null,
          createdAt: Number(row.created_at ?? 0) || null,
          updatedAt: Number(row.updated_at ?? 0) || null,
        });
      }
      return { runs, limit: capped };
    },
  };
}

export const agentCodeRunAdminConfigInternals = {
  CONFIG_SCOPE,
  CONFIG_TABLE,
  DEFAULT_TASK_TYPES,
  defaultConfigShape,
  buildConfigFromEnv,
  mergePatch,
  flattenPolicy,
};