package tools

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

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

// BrowserParams defines parameters for the browser tool.
type BrowserParams struct {
	URL string `json:"url" description:"The URL to fetch and extract text from"`
}

// Browser creates a simple web content fetcher tool.
// It fetches a URL and returns the text content.
//
// For a full headless browser, consider using an MCP server like Playwright MCP.
//
// Example:
//
//	tools := llm.NewToolBox(tools.Browser())
func Browser() llm.Tool {
	return llm.Define[BrowserParams]("browser", "Fetch a web page and return its text content",
		func(ctx context.Context, p BrowserParams) (string, error) {
			req, err := http.NewRequestWithContext(ctx, http.MethodGet, p.URL, nil)
			if err != nil {
				return "", fmt.Errorf("creating request: %w", err)
			}
			req.Header.Set("User-Agent", "go-llm/2.0 (Web Fetcher)")

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

			// Limit to 1MB
			limited := io.LimitReader(resp.Body, 1<<20)
			body, err := io.ReadAll(limited)
			if err != nil {
				return "", fmt.Errorf("reading body: %w", err)
			}

			result := map[string]any{
				"url":          p.URL,
				"status":       resp.StatusCode,
				"content_type": resp.Header.Get("Content-Type"),
				"body":         string(body),
			}

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