Files
CodingSandbox/UserPermissionTest_CS_WinForms/PostgreSqlUserRepository.cs
T
2026-05-31 15:54:46 +03:00

445 lines
19 KiB
C#

using System;
using System.Collections.Generic;
using System.Linq;
using Npgsql;
namespace UserPermissionTest_CS_WinForms
{
public class PostgreSqlUserRepository : IUserRepository
{
private readonly string _connectionString;
public PostgreSqlUserRepository(string connectionString)
{
_connectionString = connectionString ?? throw new ArgumentNullException(nameof(connectionString));
InitializeDatabaseSchema();
}
private void InitializeDatabaseSchema()
{
using (var conn = new NpgsqlConnection(_connectionString))
{
conn.Open();
// Dynamic Migration Drop: If available_permissions exists with old text primary key structure
bool needsRebuild = false;
try
{
// Check if the table has the 'id' column. If not, this throws an exception, triggering the rebuild!
using (var cmd = new NpgsqlCommand("SELECT id FROM available_permissions LIMIT 1;", conn))
{
cmd.ExecuteNonQuery();
}
}
catch
{
needsRebuild = true;
}
if (needsRebuild)
{
using (var cmd = new NpgsqlCommand(@"
DROP TABLE IF EXISTS user_permissions;
DROP TABLE IF EXISTS available_permissions;", conn))
{
cmd.ExecuteNonQuery();
}
}
// Create users table
using (var cmd = new NpgsqlCommand(@"
CREATE TABLE IF NOT EXISTS users (
username VARCHAR(50) PRIMARY KEY,
fullname VARCHAR(100) NOT NULL,
password VARCHAR(255) NOT NULL
);", conn))
{
cmd.ExecuteNonQuery();
}
// Create available_permissions table (ID-based)
using (var cmd = new NpgsqlCommand(@"
CREATE TABLE IF NOT EXISTS available_permissions (
id INT PRIMARY KEY,
name VARCHAR(100) UNIQUE NOT NULL
);", conn))
{
cmd.ExecuteNonQuery();
}
// Create user_permissions table (mapping username to permission_id)
using (var cmd = new NpgsqlCommand(@"
CREATE TABLE IF NOT EXISTS user_permissions (
username VARCHAR(50) REFERENCES users(username) ON DELETE CASCADE,
permission_id INT REFERENCES available_permissions(id) ON DELETE CASCADE,
PRIMARY KEY (username, permission_id)
);", conn))
{
cmd.ExecuteNonQuery();
}
// 1. Auto-Seed default available permissions if empty
using (var cmd = new NpgsqlCommand("SELECT COUNT(*) FROM available_permissions;", conn))
{
long count = (long)cmd.ExecuteScalar();
if (count == 0)
{
foreach (var perm in GetDefaultPermissions())
{
using (var insertCmd = new NpgsqlCommand(@"
INSERT INTO available_permissions (id, name)
VALUES (@id, @name)
ON CONFLICT (id) DO NOTHING;", conn))
{
insertCmd.Parameters.AddWithValue("@id", perm.Id);
insertCmd.Parameters.AddWithValue("@name", perm.Name);
insertCmd.ExecuteNonQuery();
}
}
}
}
// 2. Auto-Seed default users if empty
using (var cmd = new NpgsqlCommand("SELECT COUNT(*) FROM users;", conn))
{
long count = (long)cmd.ExecuteScalar();
if (count == 0)
{
foreach (var user in GetDefaultUsers())
{
using (var insertCmd = new NpgsqlCommand(@"
INSERT INTO users (username, fullname, password)
VALUES (@username, @fullname, @password)
ON CONFLICT (username) DO NOTHING;", conn))
{
insertCmd.Parameters.AddWithValue("@username", user.Username);
insertCmd.Parameters.AddWithValue("@fullname", user.FullName);
insertCmd.Parameters.AddWithValue("@password", user.Password);
insertCmd.ExecuteNonQuery();
}
}
}
}
// 3. Self-healing permissions: check if 'admin' exists but has 0 permissions, and restore
using (var checkCmd = new NpgsqlCommand("SELECT COUNT(*) FROM users WHERE username = 'admin';", conn))
{
long adminExists = (long)checkCmd.ExecuteScalar();
if (adminExists > 0)
{
using (var permCountCmd = new NpgsqlCommand("SELECT COUNT(*) FROM user_permissions WHERE username = 'admin';", conn))
{
long adminPermsCount = (long)permCountCmd.ExecuteScalar();
if (adminPermsCount == 0)
{
foreach (int permId in new int[] { 1, 2, 3, 4, 5 })
{
using (var insertCmd = new NpgsqlCommand(@"
INSERT INTO user_permissions (username, permission_id)
VALUES ('admin', @permId)
ON CONFLICT DO NOTHING;", conn))
{
insertCmd.Parameters.AddWithValue("@permId", permId);
insertCmd.ExecuteNonQuery();
}
}
}
}
}
}
// 4. Self-healing permissions: check if 'user' exists but has 0 permissions, and restore
using (var checkCmd = new NpgsqlCommand("SELECT COUNT(*) FROM users WHERE username = 'user';", conn))
{
long userExists = (long)checkCmd.ExecuteScalar();
if (userExists > 0)
{
using (var permCountCmd = new NpgsqlCommand("SELECT COUNT(*) FROM user_permissions WHERE username = 'user';", conn))
{
long userPermsCount = (long)permCountCmd.ExecuteScalar();
if (userPermsCount == 0)
{
using (var insertCmd = new NpgsqlCommand(@"
INSERT INTO user_permissions (username, permission_id)
VALUES ('user', 1)
ON CONFLICT DO NOTHING;", conn))
{
insertCmd.ExecuteNonQuery();
}
}
}
}
}
}
}
public List<User> LoadUsers()
{
var users = new List<User>();
try
{
using (var conn = new NpgsqlConnection(_connectionString))
{
conn.Open();
// Read users
using (var cmd = new NpgsqlCommand("SELECT username, fullname, password FROM users;", conn))
using (var reader = cmd.ExecuteReader())
{
while (reader.Read())
{
users.Add(new User
{
Username = reader.GetString(0),
FullName = reader.GetString(1),
Password = reader.GetString(2),
Permissions = new List<int>()
});
}
}
// Read permission IDs for each user
foreach (var user in users)
{
using (var cmd = new NpgsqlCommand("SELECT permission_id FROM user_permissions WHERE username = @username;", conn))
{
cmd.Parameters.AddWithValue("@username", user.Username);
using (var reader = cmd.ExecuteReader())
{
while (reader.Read())
{
user.Permissions.Add(reader.GetInt32(0));
}
}
}
}
}
}
catch (Exception ex)
{
Console.WriteLine("Error loading users from PostgreSQL: " + ex.Message);
}
// Fallback if no users exist in database
if (users.Count == 0)
{
var defaults = GetDefaultUsers();
SaveUsers(defaults);
return defaults;
}
return users;
}
public void SaveUsers(List<User> users)
{
try
{
using (var conn = new NpgsqlConnection(_connectionString))
{
conn.Open();
using (var trans = conn.BeginTransaction())
{
// 1. Delete users from database that are no longer in the input list
var currentInDb = new List<string>();
using (var cmd = new NpgsqlCommand("SELECT username FROM users;", conn))
using (var reader = cmd.ExecuteReader())
{
while (reader.Read())
{
currentInDb.Add(reader.GetString(0));
}
}
var usernamesToKeep = new HashSet<string>(users.Select(u => u.Username), StringComparer.OrdinalIgnoreCase);
foreach (var dbUser in currentInDb)
{
if (!usernamesToKeep.Contains(dbUser))
{
using (var cmd = new NpgsqlCommand("DELETE FROM users WHERE username = @username;", conn))
{
cmd.Parameters.AddWithValue("@username", dbUser);
cmd.ExecuteNonQuery();
}
}
}
// 2. Insert or Update users and sync permissions
foreach (var user in users)
{
using (var cmd = new NpgsqlCommand(@"
INSERT INTO users (username, fullname, password)
VALUES (@username, @fullname, @password)
ON CONFLICT (username)
DO UPDATE SET fullname = EXCLUDED.fullname, password = EXCLUDED.password;", conn))
{
cmd.Parameters.AddWithValue("@username", user.Username);
cmd.Parameters.AddWithValue("@fullname", user.FullName);
cmd.Parameters.AddWithValue("@password", user.Password);
cmd.ExecuteNonQuery();
}
// Re-sync permissions: clear old permissions and write current ones
using (var cmd = new NpgsqlCommand("DELETE FROM user_permissions WHERE username = @username;", conn))
{
cmd.Parameters.AddWithValue("@username", user.Username);
cmd.ExecuteNonQuery();
}
foreach (var permissionId in user.Permissions)
{
using (var cmd = new NpgsqlCommand(@"
INSERT INTO user_permissions (username, permission_id)
VALUES (@username, @permissionId)
ON CONFLICT DO NOTHING;", conn))
{
cmd.Parameters.AddWithValue("@username", user.Username);
cmd.Parameters.AddWithValue("@permissionId", permissionId);
cmd.ExecuteNonQuery();
}
}
}
trans.Commit();
}
}
}
catch (Exception ex)
{
Console.WriteLine("Error saving users to PostgreSQL: " + ex.Message);
}
}
public List<Permission> LoadPermissions()
{
var permissions = new List<Permission>();
try
{
using (var conn = new NpgsqlConnection(_connectionString))
{
conn.Open();
using (var cmd = new NpgsqlCommand("SELECT id, name FROM available_permissions ORDER BY id;", conn))
using (var reader = cmd.ExecuteReader())
{
while (reader.Read())
{
permissions.Add(new Permission
{
Id = reader.GetInt32(0),
Name = reader.GetString(1)
});
}
}
}
}
catch (Exception ex)
{
Console.WriteLine("Error loading permissions from PostgreSQL: " + ex.Message);
}
if (permissions.Count == 0)
{
var defaults = GetDefaultPermissions();
SavePermissions(defaults);
return defaults;
}
return permissions;
}
public void SavePermissions(List<Permission> permissions)
{
try
{
using (var conn = new NpgsqlConnection(_connectionString))
{
conn.Open();
using (var trans = conn.BeginTransaction())
{
// Sync system permissions
var currentInDb = new List<int>();
using (var cmd = new NpgsqlCommand("SELECT id FROM available_permissions;", conn))
using (var reader = cmd.ExecuteReader())
{
while (reader.Read())
{
currentInDb.Add(reader.GetInt32(0));
}
}
var permissionsToKeep = new HashSet<int>(permissions.Select(p => p.Id));
foreach (var dbPermId in currentInDb)
{
if (!permissionsToKeep.Contains(dbPermId))
{
using (var cmd = new NpgsqlCommand("DELETE FROM available_permissions WHERE id = @id;", conn))
{
cmd.Parameters.AddWithValue("@id", dbPermId);
cmd.ExecuteNonQuery();
}
}
}
foreach (var perm in permissions)
{
using (var cmd = new NpgsqlCommand(@"
INSERT INTO available_permissions (id, name)
VALUES (@id, @name)
ON CONFLICT (id) DO UPDATE SET name = EXCLUDED.name;", conn))
{
cmd.Parameters.AddWithValue("@id", perm.Id);
cmd.Parameters.AddWithValue("@name", perm.Name);
cmd.ExecuteNonQuery();
}
}
trans.Commit();
}
}
}
catch (Exception ex)
{
Console.WriteLine("Error saving permissions to PostgreSQL: " + ex.Message);
}
}
private List<User> GetDefaultUsers()
{
return new List<User>
{
new User
{
Username = "admin",
FullName = "System Administrator",
Password = PasswordHasher.HashPassword("admin"),
Permissions = new List<int> { 1, 2, 3, 4, 5 }
},
new User
{
Username = "user",
FullName = "Standard User",
Password = PasswordHasher.HashPassword("user"),
Permissions = new List<int> { 1 }
}
};
}
private List<Permission> GetDefaultPermissions()
{
return new List<Permission>
{
new Permission { Id = 1, Name = "View Dashboard" },
new Permission { Id = 2, Name = "Edit Settings" },
new Permission { Id = 3, Name = "Manage Users" },
new Permission { Id = 4, Name = "Full Control" },
new Permission { Id = 5, Name = "Delete Transactions" }
};
}
}
}