// Package knowledge exposes the knowledge base as LLM tools.
package knowledge

import (
	"context"
	"fmt"
	"strings"

	"git.yeij.top/AskaEth/Cyrene_v2/internal/plugin"
	"git.yeij.top/AskaEth/Cyrene_v2/services/rag"
)

// Store is the subset of rag.Store used by the tools.
type Store interface {
	Ingest(ctx context.Context, userID, title, content string) (*rag.Document, error)
	Search(ctx context.Context, userID, query string, topK int) ([]rag.Document, error)
}

type Plugin struct{ store Store }

func New(store Store) *Plugin { return &Plugin{store: store} }

func (p *Plugin) Name() string        { return "knowledge" }
func (p *Plugin) Version() string     { return "1.0.0" }
func (p *Plugin) Description() string { return "知识库检索与写入" }
func (p *Plugin) Init(_ context.Context, _ plugin.PluginConfig) error { return nil }
func (p *Plugin) Close() error        { return nil }
func (p *Plugin) Enabled() bool       { return p.store != nil }

func (p *Plugin) Tools() []plugin.ToolDefinition {
	return []plugin.ToolDefinition{
		{
			Name:        "knowledge_search",
			Description: "Search the knowledge base for relevant documents.",
			Parameters: map[string]any{
				"type": "object",
				"properties": map[string]any{
					"query": map[string]string{"type": "string", "description": "Search query"},
				},
				"required": []string{"query"},
			},
		},
		{
			Name:        "knowledge_ingest",
			Description: "Save a piece of information into the knowledge base for later retrieval.",
			Parameters: map[string]any{
				"type": "object",
				"properties": map[string]any{
					"title":   map[string]string{"type": "string", "description": "Document title"},
					"content": map[string]string{"type": "string", "description": "Document content"},
				},
				"required": []string{"title", "content"},
			},
		},
	}
}

func (p *Plugin) Execute(ctx context.Context, toolName string, params map[string]any) (string, error) {
	if p.store == nil {
		return "", fmt.Errorf("knowledge store unavailable")
	}
	switch toolName {
	case "knowledge_search":
		query, _ := params["query"].(string)
		if query == "" {
			return "", fmt.Errorf("missing query")
		}
		docs, err := p.store.Search(ctx, "", query, 5)
		if err != nil {
			return "", err
		}
		if len(docs) == 0 {
			return "知识库中没有相关内容", nil
		}
		var sb strings.Builder
		for i, d := range docs {
			fmt.Fprintf(&sb, "%d. 《%s》\n%s\n\n", i+1, d.Title, d.Content)
		}
		return sb.String(), nil

	case "knowledge_ingest":
		title, _ := params["title"].(string)
		content, _ := params["content"].(string)
		if title == "" || content == "" {
			return "", fmt.Errorf("missing title or content")
		}
		if _, err := p.store.Ingest(ctx, "", title, content); err != nil {
			return "", err
		}
		return fmt.Sprintf("已收录《%s》", title), nil
	}
	return "", fmt.Errorf("unknown tool %q", toolName)
}