// Package server provides MCP server implementation.
package server

import (
	"context"
)

// Config holds server configuration.
type Config struct {
	Mode      string `yaml:"mode"`
	Transport string `yaml:"transport"`
	Host      string `yaml:"host"`
	Port      int    `yaml:"port"`
}

// Server defines the MCP server interface.
type Server interface {
	// Start begins listening for connections.
	Start(ctx context.Context) error

	// Stop gracefully shuts down the server.
	Stop(ctx context.Context) error
}

// QueryRequest represents a search query.
type QueryRequest struct {
	Query     string  `json:"query"`
	Limit     int     `json:"limit,omitempty"`
	Threshold float64 `json:"threshold,omitempty"`
}

// QueryResponse represents search results.
type QueryResponse struct {
	Query   string   `json:"query"`
	Results []Result `json:"results"`
	Total   int      `json:"total"`
	TookMs  int64    `json:"took_ms"`
}

// Result represents a single search result.
type Result struct {
	ID         string         `json:"id"`
	DocumentID string         `json:"document_id"`
	Content    string         `json:"content"`
	Score      float64        `json:"score"`
	Source     string         `json:"source"`
	Metadata   map[string]any `json:"metadata,omitempty"`
}

// NewServer creates a new MCP server.
func NewServer(config *Config) Server {
	if config.Mode == "remote" {
		return NewHTTPServer(config)
	}
	return NewStdioServer(config)
}

// NewHTTPServer creates an HTTP-based MCP server.
func NewHTTPServer(config *Config) *HTTPServer {
	return &HTTPServer{config: config}
}

// NewStdioServer creates a stdio-based MCP server.
func NewStdioServer(config *Config) *StdioServer {
	return &StdioServer{config: config}
}

// HTTPServer implements Server for HTTP transport.
type HTTPServer struct {
	config *Config
}

func (s *HTTPServer) Start(ctx context.Context) error {
	// TODO: Implement HTTP server with MCP endpoints
	return nil
}

func (s *HTTPServer) Stop(ctx context.Context) error {
	return nil
}

// StdioServer implements Server for stdio transport.
type StdioServer struct {
	config *Config
}

func (s *StdioServer) Start(ctx context.Context) error {
	// TODO: Implement stdio JSON-RPC server
	return nil
}

func (s *StdioServer) Stop(ctx context.Context) error {
	return nil
}