package provider

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

type apiClient struct {
	baseURL    string
	httpClient *http.Client
}

func newAPIClient(baseURL string) *apiClient {
	return &apiClient{
		baseURL:    baseURL,
		httpClient: &http.Client{},
	}
}

func (c *apiClient) get(ctx context.Context, path string, out any) error {
	return c.do(ctx, http.MethodGet, path, nil, out)
}

func (c *apiClient) post(ctx context.Context, path string, body, out any) error {
	return c.do(ctx, http.MethodPost, path, body, out)
}

func (c *apiClient) put(ctx context.Context, path string, body, out any) error {
	return c.do(ctx, http.MethodPut, path, body, out)
}

func (c *apiClient) del(ctx context.Context, path string) error {
	return c.do(ctx, http.MethodDelete, path, nil, nil)
}

func (c *apiClient) do(ctx context.Context, method, path string, body, out any) error {
	var bodyReader io.Reader
	if body != nil {
		b, err := json.Marshal(body)
		if err != nil {
			return fmt.Errorf("marshal request: %w", err)
		}
		bodyReader = bytes.NewReader(b)
	}

	req, err := http.NewRequestWithContext(ctx, method, c.baseURL+path, bodyReader)
	if err != nil {
		return fmt.Errorf("create request: %w", err)
	}
	if body != nil {
		req.Header.Set("Content-Type", "application/json")
	}

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

	if resp.StatusCode == http.StatusNotFound {
		return &notFoundError{path: path}
	}

	if resp.StatusCode >= 400 {
		b, _ := io.ReadAll(resp.Body)
		return fmt.Errorf("api error %d: %s", resp.StatusCode, string(b))
	}

	if out != nil && resp.StatusCode != http.StatusNoContent {
		if err := json.NewDecoder(resp.Body).Decode(out); err != nil {
			return fmt.Errorf("decode response: %w", err)
		}
	}

	return nil
}

type notFoundError struct {
	path string
}

func (e *notFoundError) Error() string {
	return fmt.Sprintf("not found: %s", e.path)
}

func isNotFound(err error) bool {
	_, ok := err.(*notFoundError)
	return ok
}