package main

import (
	"context"
	"encoding/json"
	"strings"
	"time"

	"git.yeij.top/AskaEth/Cyrene_v2/internal/capability/mcp"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/capability/registry"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/config"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/logger"
)

// mcpConnectTimeout 约束每个 MCP server 的连接+发现握手，使挂死的 server 降级为
// 一条告警，而不是阻塞启动。
const mcpConnectTimeout = 15 * time.Second

// wireMCP 读取 cfg.MCP.ServersJSON，连接每个已启用的 server，把发现到的工具注册进
// 能力注册表（KindTool，使 agent 可调用它们），并暴露一个 KindMCP 能力，让管理面板
// 的插件列表能枚举该 server。连接失败或未配置的 server 降级为一条告警，绝不阻塞
// 启动。
func (a *app) wireMCP() {
	log := logger.WithSource(a.log, "cmd/cyrene")
	servers, err := a.mcpServers()
	if err != nil {
		log.Warn("mcp config parse skipped", "error", err)
		return
	}
	if len(servers) == 0 {
		log.Debug("no mcp servers configured")
		return
	}
	for _, srv := range servers {
		if !srv.Enabled {
			continue
		}
		ctx, cancel := context.WithTimeout(context.Background(), mcpConnectTimeout)
		err := a.registerMCPServer(ctx, srv)
		cancel()
		if err != nil {
			log.Warn("mcp server skipped", "name", srv.Name, "error", err)
		}
	}
}

// mcpServers 从 cfg.MCP.ServersJSON 解析出已配置的 MCP server。
func (a *app) mcpServers() ([]config.MCPServer, error) {
	raw := strings.TrimSpace(a.cfg.MCP.ServersJSON)
	if raw == "" {
		return nil, nil
	}
	var servers []config.MCPServer
	if err := json.Unmarshal([]byte(raw), &servers); err != nil {
		return nil, err
	}
	return servers, nil
}

// registerMCPServer 连接单个 server，注册其工具，并以 "mcp:<name>" 发布一个
// KindMCP 能力。它返回第一个错误以便调用方分类；注册中途失败时会清理已加入的内容。
func (a *app) registerMCPServer(ctx context.Context, srv config.MCPServer) error {
	log := logger.WithSource(a.log, "cmd/cyrene")
	reg := mcp.NewRegistry(a.caps, mcp.MCPConfig{
		Name:    srv.Name,
		Command: srv.Command,
		Args:    srv.Args,
		URL:     srv.URL,
	}, mcp.WithLogger(a.log))
	if err := reg.Register(ctx); err != nil {
		_ = reg.Unregister(context.Background())
		return err
	}
	if err := a.caps.Register(registry.Capability{
		Name:        "mcp:" + srv.Name,
		Kind:        registry.KindMCP,
		Description: "MCP server " + srv.Name,
		Value:       reg,
	}); err != nil {
		log.Warn("mcp capability register skipped", "name", srv.Name, "error", err)
	}
	a.mcpRegs = append(a.mcpRegs, reg)
	log.Info("mcp server registered", "name", srv.Name)
	return nil
}