package main

import (
	"context"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"
	"os"
	"time"

	"github.com/spf13/cobra"
	"github.com/spf13/viper"
)

var (
	dbUsername string
	dbToken    string
)

type DatabaseCredentials struct {
	Host     string `json:"host"`
	Port     int    `json:"port"`
	Name     string `json:"name"`
	User     string `json:"user"`
	Password string `json:"password"`
}

type ErrorResponse struct {
	Error string `json:"error"`
}

var databaseCmd = &cobra.Command{
	Use:   "database",
	Short: "Manage database credentials",
	Long:  `Commands for managing database credentials in the MCIAS system.`,
}

var addDBUserCmd = &cobra.Command{
	Use:   "add-user [database-id] [user-id]",
	Short: "Associate a user with a database",
	Long:  `Associate a user with a database, allowing them to read its credentials.`,
	Args:  cobra.ExactArgs(2),
	Run: func(cmd *cobra.Command, args []string) {
		addUserToDatabase(args[0], args[1])
	},
}

var removeDBUserCmd = &cobra.Command{
	Use:   "remove-user [database-id] [user-id]",
	Short: "Remove a user's association with a database",
	Long:  `Remove a user's association with a database, preventing them from reading its credentials.`,
	Args:  cobra.ExactArgs(2),
	Run: func(_ *cobra.Command, args []string) {
		removeUserFromDatabase(args[0], args[1])
	},
}

var listDBUsersCmd = &cobra.Command{
	Use:   "list-users [database-id]",
	Short: "List users associated with a database",
	Long:  `List all users who have access to read the credentials of a specific database.`,
	Args:  cobra.ExactArgs(1),
	Run: func(_ *cobra.Command, args []string) {
		listDatabaseUsers(args[0])
	},
}

var getCredentialsCmd = &cobra.Command{
	Use:   "credentials",
	Short: "Get database credentials",
	Long: `Retrieve database credentials from the MCIAS system.
This command requires authentication with a username and token.`,
	Run: func(_ *cobra.Command, args []string) {
		getCredentials()
	},
}

func init() {
	rootCmd.AddCommand(databaseCmd)
	databaseCmd.AddCommand(getCredentialsCmd)
	databaseCmd.AddCommand(addDBUserCmd)
	databaseCmd.AddCommand(removeDBUserCmd)
	databaseCmd.AddCommand(listDBUsersCmd)

	getCredentialsCmd.Flags().StringVarP(&dbUsername, "username", "u", "", "Username for authentication")
	getCredentialsCmd.Flags().StringVarP(&dbToken, "token", "t", "", "Authentication token")
	if err := getCredentialsCmd.MarkFlagRequired("username"); err != nil {
		fmt.Fprintf(os.Stderr, "Error marking username flag as required: %v\n", err)
	}
	if err := getCredentialsCmd.MarkFlagRequired("token"); err != nil {
		fmt.Fprintf(os.Stderr, "Error marking token flag as required: %v\n", err)
	}
}

func getCredentials() {
	logger := log.New(os.Stdout, "MCIAS: ", log.LstdFlags)

	serverAddr := viper.GetString("server")
	if serverAddr == "" {
		serverAddr = "http://localhost:8080"
	}

	url := fmt.Sprintf("%s/v1/database/credentials?username=%s", serverAddr, dbUsername)

	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
	defer cancel()

	req, err := http.NewRequestWithContext(ctx, "GET", url, nil)
	if err != nil {
		logger.Fatalf("Failed to create request: %v", err)
	}

	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", dbToken))

	client := &http.Client{}
	resp, err := client.Do(req)
	if err != nil {
		logger.Fatalf("Failed to send request: %v", err)
	}
	defer resp.Body.Close()

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		logger.Fatalf("Failed to read response: %v", err)
	}

	if resp.StatusCode != http.StatusOK {
		var errResp ErrorResponse
		if unmarshalErr := json.Unmarshal(body, &errResp); unmarshalErr == nil {
			logger.Fatalf("Error: %s", errResp.Error)
		} else {
			logger.Fatalf("Error: %s", resp.Status)
		}
	}

	var creds DatabaseCredentials
	if unmarshalErr := json.Unmarshal(body, &creds); unmarshalErr != nil {
		logger.Fatalf("Failed to parse response: %v", unmarshalErr)
	}

	fmt.Println("Database Credentials:")
	fmt.Printf("Host:     %s\n", creds.Host)
	fmt.Printf("Port:     %d\n", creds.Port)
	fmt.Printf("Name:     %s\n", creds.Name)
	fmt.Printf("User:     %s\n", creds.User)
	fmt.Printf("Password: %s\n", creds.Password)
}