package tools

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

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

// HTTPParams defines parameters for the HTTP request tool.
type HTTPParams struct {
	Method  string            `json:"method" description:"HTTP method" enum:"GET,POST,PUT,DELETE,PATCH,HEAD"`
	URL     string            `json:"url" description:"Request URL"`
	Headers map[string]string `json:"headers,omitempty" description:"Request headers"`
	Body    *string           `json:"body,omitempty" description:"Request body"`
}

// HTTP creates an HTTP request tool.
//
// Example:
//
//	tools := llm.NewToolBox(tools.HTTP())
func HTTP() llm.Tool {
	return llm.Define[HTTPParams]("http_request", "Make an HTTP request and return the response",
		func(ctx context.Context, p HTTPParams) (string, error) {
			var bodyReader io.Reader
			if p.Body != nil {
				bodyReader = bytes.NewBufferString(*p.Body)
			}

			req, err := http.NewRequestWithContext(ctx, p.Method, p.URL, bodyReader)
			if err != nil {
				return "", fmt.Errorf("creating request: %w", err)
			}

			for k, v := range p.Headers {
				req.Header.Set(k, v)
			}

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

			headers := map[string]string{}
			for k, v := range resp.Header {
				if len(v) > 0 {
					headers[k] = v[0]
				}
			}

			result := map[string]any{
				"status":      resp.StatusCode,
				"status_text": resp.Status,
				"headers":     headers,
				"body":        string(body),
			}

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