package auth

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

	"github.com/claudia/docs-cli/internal/api"
	"github.com/claudia/docs-cli/internal/config"
	"github.com/claudia/docs-cli/pkg/types"
)

// AuthClient handles authentication
type AuthClient struct {
	client *api.Client
}

// NewAuthClient creates a new auth client
func NewAuthClient(c *api.Client) *AuthClient {
	return &AuthClient{client: c}
}

// Login authenticates a user and returns the token
func (a *AuthClient) Login(username, password string) (*types.AuthResponse, error) {
	req := types.LoginRequest{
		Username: username,
		Password: password,
	}

	resp, err := a.client.DoRequest(http.MethodPost, "/auth/login", req)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()

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

	if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusCreated {
		return nil, handleAuthError(resp, body)
	}

	var authResp types.Response
	if err := json.Unmarshal(body, &authResp); err != nil {
		return nil, err
	}

	return mapToAuthResponse(authResp.Data), nil
}

// Register registers a new user
func (a *AuthClient) Register(username, password string) (*types.AuthResponse, error) {
	req := types.RegisterRequest{
		Username: username,
		Password: password,
	}

	resp, err := a.client.DoRequest(http.MethodPost, "/auth/register", req)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()

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

	if resp.StatusCode != http.StatusCreated && resp.StatusCode != http.StatusOK {
		return nil, handleAuthError(resp, body)
	}

	var authResp types.Response
	if err := json.Unmarshal(body, &authResp); err != nil {
		return nil, err
	}

	return mapToAuthResponse(authResp.Data), nil
}

// Me returns the current user info
func (a *AuthClient) Me() (map[string]interface{}, error) {
	resp, err := a.client.DoRequest(http.MethodGet, "/auth/me", nil)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()

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

	if resp.StatusCode != http.StatusOK {
		return nil, handleAuthError(resp, body)
	}

	var authResp types.Response
	if err := json.Unmarshal(body, &authResp); err != nil {
		return nil, err
	}

	if m, ok := authResp.Data.(map[string]interface{}); ok {
		return m, nil
	}
	return nil, fmt.Errorf("unexpected response format")
}

// Logout clears the saved token
func Logout() error {
	return config.ClearToken()
}

// Status returns the current auth status
func Status() (map[string]interface{}, error) {
	cfg := config.GetConfig()
	if cfg == nil {
		return map[string]interface{}{
			"authenticated": false,
			"server":         "http://localhost:8000",
		}, nil
	}

	token := cfg.Token
	if token == "" {
		return map[string]interface{}{
			"authenticated": false,
			"server":        cfg.Server,
		}, nil
	}

	return map[string]interface{}{
		"authenticated": true,
		"server":        cfg.Server,
	}, nil
}

func handleAuthError(resp *http.Response, body []byte) error {
	var authResp types.Response
	if err := json.Unmarshal(body, &authResp); err != nil {
		return fmt.Errorf("HTTP %d: %s", resp.StatusCode, string(body))
	}
	if authResp.Error != nil {
		return fmt.Errorf("%s: %s", authResp.Error.Code, authResp.Error.Message)
	}
	return fmt.Errorf("HTTP %d", resp.StatusCode)
}

func mapToAuthResponse(data interface{}) *types.AuthResponse {
	resp := &types.AuthResponse{}
	if m, ok := data.(map[string]interface{}); ok {
		if v, ok := m["access_token"].(string); ok {
			resp.Token = v
		}
		if v, ok := m["token_type"].(string); ok {
			resp.TokenType = v
		}
		if v, ok := m["expires_at"].(string); ok {
			resp.ExpiresAt, _ = time.Parse(time.RFC3339, v)
		} else if v, ok := m["expires_at"].(float64); ok {
			resp.ExpiresAt = time.Unix(int64(v), 0)
		}
	}
	return resp
}