package api

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

	"code.gitea.io/sdk/gitea"
	"forgejo.zerova.net/public/fj/internal/config"
)

var sharedHTTPClient = &http.Client{
	Timeout: 30 * time.Second,
}

type Client struct {
	*gitea.Client
	hostname string
	token    string
}

func NewClient(hostname, token string) (*Client, error) {
	if hostname == "" {
		hostname = "codeberg.org"
	}

	client, err := gitea.NewClient("https://"+hostname, gitea.SetToken(token))
	if err != nil {
		return nil, err
	}

	return &Client{
		Client:   client,
		hostname: hostname,
		token:    token,
	}, nil
}

func NewClientFromConfig(cfg *config.Config, hostname string, detectedHost string, cwd string) (*Client, error) {
	host, err := cfg.GetHost(hostname, detectedHost, cwd)
	if err != nil {
		return nil, err
	}

	return NewClient(host.Hostname, host.Token)
}

func (c *Client) Hostname() string {
	return c.hostname
}

// GetJSON performs a GET request to the specified path and decodes the JSON response
func (c *Client) GetJSON(path string, result any) error {
	baseURL := "https://" + c.hostname
	url := baseURL + path

	req, err := http.NewRequest(http.MethodGet, url, nil)
	if err != nil {
		return fmt.Errorf("failed to create request: %w", err)
	}

	// Set authentication header
	if c.token != "" {
		req.Header.Set("Authorization", "token "+c.token)
	}
	req.Header.Set("Accept", "application/json")

	resp, err := sharedHTTPClient.Do(req)
	if err != nil {
		return fmt.Errorf("failed to perform request: %w", err)
	}
	defer func() {
		if closeErr := resp.Body.Close(); closeErr != nil && err == nil {
			err = fmt.Errorf("failed to close response body: %w", closeErr)
		}
	}()

	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
		body, readErr := io.ReadAll(resp.Body)
		if readErr != nil {
			return fmt.Errorf("failed to read error response body: %w", readErr)
		}
		return &APIError{
			StatusCode: resp.StatusCode,
			Body:       string(body),
			Message:    fmt.Sprintf("API request failed with status %d: %s", resp.StatusCode, string(body)),
		}
	}

	if err := json.NewDecoder(resp.Body).Decode(result); err != nil {
		return fmt.Errorf("failed to decode response: %w", err)
	}

	return nil
}

// PostJSON performs a POST request to the specified path with JSON body
func (c *Client) PostJSON(path string, body any, result any) error {
	_, err := c.DoJSON(http.MethodPost, path, body, result)
	return err
}

// DoJSON performs an HTTP request with a JSON body and decodes the JSON response.
// Returns the HTTP status code and any error encountered.
func (c *Client) DoJSON(method string, path string, body any, result any) (int, error) {
	baseURL := "https://" + c.hostname
	url := baseURL + path

	var bodyReader io.Reader
	if body != nil {
		bodyBytes, err := json.Marshal(body)
		if err != nil {
			return 0, fmt.Errorf("failed to marshal request body: %w", err)
		}
		bodyReader = bytes.NewReader(bodyBytes)
	}

	req, err := http.NewRequest(method, url, bodyReader)
	if err != nil {
		return 0, fmt.Errorf("failed to create request: %w", err)
	}

	// Set authentication header
	if c.token != "" {
		req.Header.Set("Authorization", "token "+c.token)
	}
	req.Header.Set("Accept", "application/json")
	if body != nil {
		req.Header.Set("Content-Type", "application/json")
	}

	resp, err := sharedHTTPClient.Do(req)
	if err != nil {
		return 0, fmt.Errorf("failed to perform request: %w", err)
	}
	defer func() {
		if closeErr := resp.Body.Close(); closeErr != nil && err == nil {
			err = fmt.Errorf("failed to close response body: %w", closeErr)
		}
	}()

	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
		bodyBytes, readErr := io.ReadAll(resp.Body)
		if readErr != nil {
			return resp.StatusCode, fmt.Errorf("failed to read error response body: %w", readErr)
		}
		return resp.StatusCode, &APIError{
			StatusCode: resp.StatusCode,
			Body:       string(bodyBytes),
			Message:    fmt.Sprintf("API request failed with status %d: %s", resp.StatusCode, string(bodyBytes)),
		}
	}

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

	return resp.StatusCode, nil
}

// Token returns the client's authentication token.
func (c *Client) Token() string {
	return c.token
}

// DownloadFile performs an authenticated GET request and writes the response body to the given writer.
func (c *Client) DownloadFile(url string, w io.Writer) error {
	req, err := http.NewRequest(http.MethodGet, url, nil)
	if err != nil {
		return fmt.Errorf("failed to create request: %w", err)
	}

	if c.token != "" {
		req.Header.Set("Authorization", "token "+c.token)
	}

	resp, err := sharedHTTPClient.Do(req)
	if err != nil {
		return fmt.Errorf("failed to perform request: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		body, _ := io.ReadAll(resp.Body)
		return fmt.Errorf("download failed with status %d: %s", resp.StatusCode, string(body))
	}

	if _, err := io.Copy(w, resp.Body); err != nil {
		return fmt.Errorf("failed to write file: %w", err)
	}

	return nil
}

// GetRawLog performs a GET request and returns the raw response body as string
func (c *Client) GetRawLog(url string) (string, error) {
	req, err := http.NewRequest(http.MethodGet, url, nil)
	if err != nil {
		return "", fmt.Errorf("failed to create request: %w", err)
	}

	// Set authentication header
	if c.token != "" {
		req.Header.Set("Authorization", "token "+c.token)
	}

	resp, err := sharedHTTPClient.Do(req)
	if err != nil {
		return "", fmt.Errorf("failed to perform request: %w", err)
	}
	defer func() {
		if closeErr := resp.Body.Close(); closeErr != nil && err == nil {
			err = fmt.Errorf("failed to close response body: %w", closeErr)
		}
	}()

	if resp.StatusCode != http.StatusOK {
		body, readErr := io.ReadAll(resp.Body)
		if readErr != nil {
			return "", fmt.Errorf("failed to read error response body: %w", readErr)
		}
		return "", &APIError{
			StatusCode: resp.StatusCode,
			Body:       string(body),
			Message:    fmt.Sprintf("API request failed with status %d: %s", resp.StatusCode, string(body)),
		}
	}

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

	return string(bodyBytes), nil
}