package standard

import (
	"fmt"
	"io"
	"net/http"
	"strings"

	"github.com/dop251/goja"
	"reichard.io/poiesis/internal/runtime/pkg/builtin"
)

type FetchResult struct {
	OK      bool
	Status  int
	Body    string
	Headers map[string]string
}

func Fetch(url string, options map[string]any) (*FetchResult, error) {
	req, err := http.NewRequest("GET", url, nil)
	if err != nil {
		return nil, fmt.Errorf("failed to create request: %w", err)
	}

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

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

	headers := make(map[string]string)
	for key, values := range resp.Header {
		if len(values) > 0 {
			val := values[0]
			headers[key] = val
			headers[strings.ToLower(key)] = val
		}
	}

	return &FetchResult{
		OK:      resp.StatusCode >= 200 && resp.StatusCode < 300,
		Status:  resp.StatusCode,
		Body:    string(body),
		Headers: headers,
	}, nil
}

func convertFetchResult(vm *goja.Runtime, result *FetchResult) goja.Value {
	if result == nil {
		return goja.Null()
	}

	obj := vm.NewObject()
	_ = obj.Set("ok", result.OK)
	_ = obj.Set("status", result.Status)
	_ = obj.Set("text", func() string {
		return result.Body
	})

	headersObj := vm.NewObject()
	headers := result.Headers
	_ = headersObj.Set("get", func(c goja.FunctionCall) goja.Value {
		if len(c.Arguments) < 1 {
			return goja.Undefined()
		}
		key := c.Arguments[0].String()
		return vm.ToValue(headers[key])
	})
	_ = obj.Set("headers", headersObj)

	return obj
}

func init() {
	builtin.RegisterCustomConverter(convertFetchResult)

	builtin.RegisterBuiltin("fetch", Fetch)
	builtin.RegisterBuiltin("add", func(a, b int) int {
		return a + b
	})
	builtin.RegisterBuiltin("greet", func(name string) string {
		return fmt.Sprintf("Hello, %s!", name)
	})
}