import crypto from 'node:crypto';

export const ASSET_PLUGIN_CATALOG = [
  {
    id: 'asset-search',
    label: '素材检索',
    description: '从已授权图库检索素材；不改变现有页面默认生成流程。',
    providers: ['pexels', 'unsplash'],
    supportsLlm: true,
  },
  {
    id: 'asset-generate',
    label: '图片生成',
    description: '异步生成页面所需图片；关闭或失败时必须降级为无图页面。',
    providers: ['flux-schnell', 'comfyui'],
    supportsLlm: true,
  },
  {
    id: 'asset-transform',
    label: '图片处理',
    description: '压缩、裁剪和格式转换等确定性处理。',
    providers: ['sharp'],
    supportsLlm: false,
  },
  {
    id: 'asset-analyze',
    label: '图片理解',
    description: '对图片进行描述、结构分析或辅助可访问性标注。',
    providers: ['qwen25-vl'],
    supportsLlm: true,
  },
];

const pluginById = new Map(ASSET_PLUGIN_CATALOG.map((plugin) => [plugin.id, plugin]));

function normalizePluginId(value) {
  const id = String(value ?? '').trim().toLowerCase();
  return pluginById.has(id) ? id : null;
}

function normalizeProvider(plugin, value) {
  const provider = String(value ?? '').trim().toLowerCase();
  return plugin?.providers.includes(provider) ? provider : null;
}

function toBoolean(value, defaultValue = false) {
  if (value === undefined || value === null) return defaultValue;
  return Boolean(value);
}

function rowToPluginConfig(row, providerKey = null) {
  const plugin = pluginById.get(row.plugin_id);
  return {
    pluginId: row.plugin_id,
    label: plugin?.label ?? row.plugin_id,
    description: plugin?.description ?? '',
    providers: plugin?.providers ?? [],
    supportsLlm: Boolean(plugin?.supportsLlm),
    enabled: Boolean(row.enabled),
    provider: row.provider,
    llmProviderKeyId: row.llm_provider_key_id ?? null,
    llmProviderName: providerKey?.name ?? null,
    llmProviderId: providerKey?.providerId ?? null,
    llmModel: row.llm_model ?? null,
    updatedAt: Number(row.updated_at ?? 0) || null,
  };
}

/**
 * Configuration-only control plane for optional asset plugins.
 *
 * This service deliberately does not invoke a model, external API, queue, or
 * storage. Callers must opt in to it, which keeps the current chat and page
 * generation path unchanged until a later adapter explicitly uses a plugin.
 */
export function createAssetGatewayConfigService(pool, { llmProviderService = null } = {}) {
  async function getGlobalRow() {
    const [rows] = await pool.query(
      'SELECT * FROM h5_asset_gateway_config WHERE config_key = ? LIMIT 1',
      ['default'],
    );
    return rows[0] ?? null;
  }

  async function listRows() {
    const [rows] = await pool.query('SELECT * FROM h5_asset_plugin_configs ORDER BY plugin_id');
    return rows;
  }

  async function getRow(pluginId) {
    const [rows] = await pool.query(
      'SELECT * FROM h5_asset_plugin_configs WHERE plugin_id = ? LIMIT 1',
      [pluginId],
    );
    return rows[0] ?? null;
  }

  async function listKeyMap() {
    if (!llmProviderService?.listKeys) return new Map();
    const keys = await llmProviderService.listKeys();
    return new Map(keys.map((key) => [key.id, key]));
  }

  async function ensureLlmBinding({ plugin, keyId, model, enabled }) {
    if (!plugin.supportsLlm && (keyId || model)) {
      return { ok: false, message: `${plugin.label}不支持 LLM 绑定` };
    }
    if (!enabled || (!keyId && !model)) return { ok: true };
    if (!keyId || !model) return { ok: false, message: 'LLM Provider 与模型必须同时选择' };
    if (!llmProviderService?.listKeys) return { ok: false, message: 'LLM Provider 服务未启用' };
    const key = (await llmProviderService.listKeys()).find((item) => item.id === keyId);
    if (!key || key.status !== 'active') return { ok: false, message: 'LLM Provider 不存在或已禁用' };
    if (!key.models.includes(model)) return { ok: false, message: '模型不在该 Provider 支持列表中' };
    return { ok: true };
  }

  return {
    catalog: ASSET_PLUGIN_CATALOG,

    async getConfig() {
      const [globalRow, rows, keyMap] = await Promise.all([getGlobalRow(), listRows(), listKeyMap()]);
      const byPlugin = new Map(rows.map((row) => [row.plugin_id, row]));
      return {
        enabled: Boolean(globalRow?.enabled),
        updatedAt: Number(globalRow?.updated_at ?? 0) || null,
        plugins: ASSET_PLUGIN_CATALOG.map((plugin) => {
          const row = byPlugin.get(plugin.id);
          return row
            ? rowToPluginConfig(row, keyMap.get(row.llm_provider_key_id) ?? null)
            : {
                pluginId: plugin.id,
                label: plugin.label,
                description: plugin.description,
                providers: plugin.providers,
                supportsLlm: plugin.supportsLlm,
                enabled: false,
                provider: null,
                llmProviderKeyId: null,
                llmProviderName: null,
                llmProviderId: null,
                llmModel: null,
                updatedAt: null,
              };
        }),
      };
    },

    async updateGlobalConfig(payload = {}, { updatedBy = null } = {}) {
      const enabled = toBoolean(payload.enabled);
      const now = Date.now();
      const existing = await getGlobalRow();
      if (existing) {
        await pool.query(
          'UPDATE h5_asset_gateway_config SET enabled = ?, updated_by = ?, updated_at = ? WHERE config_key = ?',
          [enabled ? 1 : 0, updatedBy, now, 'default'],
        );
      } else {
        await pool.query(
          'INSERT INTO h5_asset_gateway_config (config_key, enabled, updated_by, updated_at) VALUES (?, ?, ?, ?)',
          ['default', enabled ? 1 : 0, updatedBy, now],
        );
      }
      return this.getConfig();
    },

    async updatePluginConfig(rawPluginId, payload = {}, { updatedBy = null } = {}) {
      const pluginId = normalizePluginId(rawPluginId);
      if (!pluginId) return { ok: false, message: '不支持的资产插件' };
      const plugin = pluginById.get(pluginId);
      const enabled = toBoolean(payload.enabled);
      const provider = normalizeProvider(plugin, payload.provider);
      if (enabled && !provider) return { ok: false, message: '请选择该插件支持的 Provider' };

      const keyId = String(payload.llmProviderKeyId ?? payload.keyId ?? '').trim() || null;
      const model = String(payload.llmModel ?? payload.model ?? '').trim() || null;
      const binding = await ensureLlmBinding({ plugin, keyId, model, enabled });
      if (!binding.ok) return binding;

      const existing = await getRow(pluginId);
      const now = Date.now();
      if (existing) {
        await pool.query(
          `UPDATE h5_asset_plugin_configs
           SET enabled = ?, provider = ?, llm_provider_key_id = ?, llm_model = ?, updated_by = ?, updated_at = ?
           WHERE plugin_id = ?`,
          [enabled ? 1 : 0, provider, keyId, model, updatedBy, now, pluginId],
        );
      } else {
        await pool.query(
          `INSERT INTO h5_asset_plugin_configs
           (id, plugin_id, enabled, provider, llm_provider_key_id, llm_model, updated_by, created_at, updated_at)
           VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)`,
          [crypto.randomUUID(), pluginId, enabled ? 1 : 0, provider, keyId, model, updatedBy, now, now],
        );
      }
      return { ok: true, config: await this.getConfig() };
    },

    async resolvePlugin(rawPluginId) {
      const pluginId = normalizePluginId(rawPluginId);
      if (!pluginId) return { ok: false, code: 'unsupported_plugin', message: '不支持的资产插件' };
      const global = await getGlobalRow();
      if (!global?.enabled) {
        return { ok: false, code: 'gateway_disabled', message: '资产能力未启用，可安全降级到原有流程' };
      }
      const row = await getRow(pluginId);
      if (!row?.enabled) {
        return { ok: false, code: 'plugin_disabled', message: '资产插件未启用，可安全降级到原有流程' };
      }
      return { ok: true, plugin: rowToPluginConfig(row) };
    },
  };
}