// Package tools provides ready-to-use tool implementations for common agent patterns.
package tools

import (
	"context"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"net/url"

	llm "gitea.stevedudenhoeffer.com/steve/go-llm/v2"
)

// WebSearchParams defines parameters for the web search tool.
type WebSearchParams struct {
	Query string `json:"query" description:"The search query"`
	Count *int   `json:"count,omitempty" description:"Number of results to return (default 5, max 20)"`
}

// WebSearch creates a web search tool using the Brave Search API.
//
// Get a free API key at https://brave.com/search/api/
//
// Example:
//
//	tools := llm.NewToolBox(tools.WebSearch("your-brave-api-key"))
func WebSearch(apiKey string) llm.Tool {
	return llm.Define[WebSearchParams]("web_search", "Search the web for information using Brave Search",
		func(ctx context.Context, p WebSearchParams) (string, error) {
			count := 5
			if p.Count != nil && *p.Count > 0 {
				count = *p.Count
				if count > 20 {
					count = 20
				}
			}

			u := fmt.Sprintf("https://api.search.brave.com/res/v1/web/search?q=%s&count=%d",
				url.QueryEscape(p.Query), count)

			req, err := http.NewRequestWithContext(ctx, http.MethodGet, u, nil)
			if err != nil {
				return "", fmt.Errorf("creating request: %w", err)
			}
			req.Header.Set("Accept", "application/json")
			req.Header.Set("X-Subscription-Token", apiKey)

			resp, err := http.DefaultClient.Do(req)
			if err != nil {
				return "", fmt.Errorf("search request failed: %w", err)
			}
			defer resp.Body.Close()

			body, err := io.ReadAll(resp.Body)
			if err != nil {
				return "", fmt.Errorf("reading response: %w", err)
			}

			if resp.StatusCode != http.StatusOK {
				return "", fmt.Errorf("search API returned %d: %s", resp.StatusCode, string(body))
			}

			// Parse and simplify the response
			var raw map[string]any
			if err := json.Unmarshal(body, &raw); err != nil {
				return string(body), nil
			}

			type result struct {
				Title       string `json:"title"`
				URL         string `json:"url"`
				Description string `json:"description"`
			}

			var results []result
			if web, ok := raw["web"].(map[string]any); ok {
				if items, ok := web["results"].([]any); ok {
					for _, item := range items {
						if m, ok := item.(map[string]any); ok {
							r := result{}
							if t, ok := m["title"].(string); ok {
								r.Title = t
							}
							if u, ok := m["url"].(string); ok {
								r.URL = u
							}
							if d, ok := m["description"].(string); ok {
								r.Description = d
							}
							results = append(results, r)
						}
					}
				}
			}

			out, _ := json.MarshalIndent(results, "", "  ")
			return string(out), nil
		},
	)
}