package endpoints

import (
	"encoding/json"
	"fmt"
	"git.dragse.it/anthrove/e621-sdk-go/pkg/e621/model"
	"git.dragse.it/anthrove/e621-sdk-go/pkg/e621/utils"
	"net/http"
)

type RequestTypes interface {
	model.User |
		model.Tag |
		model.Post |
		model.PostResponse |
		model.Pool |
		model.Note |
		[]model.User |
		[]model.Tag |
		[]model.Post |
		[]model.Pool |
		[]model.Note
}

// getRequest performs an HTTP GET request to the specified e621 API endpoint and unmarshals the JSON response into the provided type T.
//
// This generic function is designed to fetch data from the e621 API using an HTTP GET request.
// It supports generic types and can unmarshal the JSON response into the provided type T.
//
// Parameters:
//   - requestContext: The context for the API request, including the host, user agent, username, and API key.
//   - e621Endpoint: The specific e621 API endpoint to be called.
//   - query: A map containing additional query parameters for the API request. (Optional)
//
// Type Parameters:
//   - T: The type into which the JSON response will be unmarshaled.
//   - supported types are (also as slice): model.User, model.Tag, model.Post, model.PostResponse, model.Pool, model.Note
//
// Returns:
//   - T: The result of unmarshaling the JSON response into the provided type.
//   - error: An error, if any, encountered during the API request, response handling, or JSON unmarshaling.
func getRequest[T RequestTypes](requestContext model.RequestContext, e621Endpoint string, query map[string]string) (T, error) {
	var base T
	// Create a new HTTP GET request to fetch user information from the specified 'host' and 'username'.
	r, err := http.NewRequest("GET", fmt.Sprintf("%s/%s", requestContext.Host, e621Endpoint), nil)
	if err != nil {
		// Log the error and return an empty User struct and the error.

		return base, err
	}

	// Append query parameters to the request URL.
	if query != nil {
		q := r.URL.Query()
		for k, v := range query {
			q.Add(k, v)
		}
		r.URL.RawQuery = q.Encode()
	}

	r.Header.Set("User-Agent", requestContext.UserAgent)
	r.Header.Add("Accept", "application/json")
	r.SetBasicAuth(requestContext.Username, requestContext.APIKey)

	// Send the request using the provided http.Client.
	resp, err := requestContext.Client.Do(r)
	if err != nil {
		// Log the error and return an empty User struct and the error.

		return base, err
	}

	// Check if the HTTP response status code indicates success (2xx range).
	if resp.StatusCode < 200 || resp.StatusCode > 300 {
		// If the status code is outside the 2xx range, return an error based on the status code.
		return base, utils.StatusCodesToError(resp.StatusCode)
	}

	// Decode the JSON response into the User struct.
	err = json.NewDecoder(resp.Body).Decode(&base)
	if err != nil {
		// Log the error and return an empty User struct and the error.

		return base, err
	}

	// Return the user information and no error (nil).
	return base, nil
}