@using System.IO
@using Rms.Service.Bootstrap.Security

@inject IPasswordManager PasswordManager

@*
 *                                dbMango
 *
 * Copyright 2025 Deutsche Bank AG
 * SPDX-License-Identifier: Apache-2.0
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *@

<div class="flex-stack-vertical">
    <div class="flex-stack-horizontal">
        <div >

            <div class="form-row">
                <div class="form-group w-100">
                    <div class="d-flex align-items-baseline mb-2">
                        <label class="mr-2">Clear text</label>
                        <button type="button" class="btn btn-secondary" @onclick="GeneratePassword">
                            <span class="ui-icon-font icon-lock-sm"></span>
                            <span class="p-1">Generate</span>
                        </button>
                    </div>
                    <textarea cols="90" rows="3" class="form-control input-group mr-3 w-100 text-monospace" placeholder="Clear text..." @bind-value="ClearText" @bind-value:event="oninput">
                    </textarea>
                </div>
            </div>


            <div class="form-row">
                <FormButton OnClick="@DoEncryption" Name="Encrypt" Enabled="@(!IsEncryptDisabled)" Icon="icon-lock-sm" />
            </div>

        </div>
    </div>

    @if (ShowFile)
    {
        <div class="form-row">
            <div class="form-group w-100" style="position: relative; top: 20px;">
                <label>Binary file:</label>
                <InputFile id="upload" OnChange="@(OnFileUploaded)" />
            </div>
        </div>
    }

    <div>
        @if (!string.IsNullOrWhiteSpace(EncryptedText))
        {
            <p class="mt-2">As password:</p>
            <textarea cols="90" rows="3" readonly class="form-control input-group mr-3 w-100 text-monospace">
                @EncryptedText
                </textarea>
        }
        @if (ShowFile && !string.IsNullOrWhiteSpace(EncryptedFile))
        {
            <p class="mt-2">As file:</p>
            <textarea cols="90" rows="10" readonly class="form-control input-group mr-3 w-100 text-monospace">
                @EncryptedFile
            </textarea>
        }
    </div>

</div>

@code {

    [Parameter] public string ClearText
    {
        get;
        set
        {
            if (field == value)
                return;
            field = value;
            ClearTextChanged.InvokeAsync(field);
            InvokeAsync(StateHasChanged);
        }
    } = "";
    [Parameter] public EventCallback<string> ClearTextChanged { get; set; }

    [Parameter] public string                EncryptedText { get; set; } = "";
    [Parameter] public EventCallback<string> EncryptedTextChanged { get; set; }

    [Parameter] public string                EncryptedFile        { get; set; } = "";
    [Parameter] public EventCallback<string> EncryptedFileChanged { get; set; }

    [Parameter] public bool ShowFile { get; set; } = false;

    private bool IsEncryptDisabled => string.IsNullOrWhiteSpace(ClearText);

    private void GeneratePassword() => ClearText = GenerateGoodPassword();

    private async Task DoEncryption()
    {
        try
        {
            EncryptedText = PasswordManager.EncryptPassword(ClearText);
            await EncryptedTextChanged.InvokeAsync(EncryptedText);
        }
        catch (Exception e)
        {
            EncryptedText = e.Message;
        }
        try
        {
            EncryptedFile = PasswordManager.EncryptFileContents(ClearText);
            await EncryptedFileChanged.InvokeAsync(EncryptedFile);
        }
        catch (Exception e)
        {
            EncryptedFile = e.Message;
        }

        ClearText = "";
        await InvokeAsync(StateHasChanged);
    }

    private async Task OnFileUploaded(InputFileChangeEventArgs arg)
    {
        await using var mem          = new MemoryStream();
        const long      oneHundredMb = 100 * 1024 * 1024;
        await arg.File.OpenReadStream(maxAllowedSize: oneHundredMb).CopyToAsync(mem);

        var byteArray = mem.ToArray();

        try
        {
            EncryptedText = "";
        }
        catch (Exception e)
        {
            EncryptedText = e.Message;
        }
        try
        {
            EncryptedFile = PasswordManager.EncryptBinaryFileContents(byteArray);
        }
        catch (Exception e)
        {
            EncryptedFile = e.Message;
        }

        ClearText = "";
        await InvokeAsync(StateHasChanged);
    }

    private static string GenerateGoodPassword()
    {
        const int    generatedPasswordLength = 24;
        const string specialChars            = "!$%^&*()_+#~/?-=";
        const string letters                 = "qwertyuioplkjhgfdsazxcvbnm";
        const string digits                  = "0123456789";
        var alphabet = specialChars
                     + letters
                     + letters.ToUpper()
                     + digits
            ;

        var password = "";
        var count    = 1000;
        while (!IsGoodPassword(password) && count > 0)
        {
            password =  "";
            count    -= 1;

            for (var i = 0; i < generatedPasswordLength; i++)
            {
                var pos = Random.Shared.Next(alphabet.Length);
                password += alphabet[pos];
            }
        }

        return password;

        bool IsGoodPassword(string s)
        {
            var hasLower   = false;
            var hasUpper   = false;
            var hasDigit   = false;
            var hasSpecial = false;

            var upper = letters.ToUpper();

            foreach (var c in s)
            {
                if (letters.IndexOf(c) >= 0)
                {
                    hasLower = true;
                    continue;
                }
                if (upper.IndexOf(c) >= 0)
                {
                    hasUpper = true;
                    continue;
                }
                if (digits.IndexOf(c) >= 0)
                {
                    hasDigit = true;
                    continue;
                }
                if (specialChars.IndexOf(c) >= 0)
                {
                    hasSpecial = true;
                }
            }

            return hasLower && hasUpper && hasDigit && hasSpecial;
        }
    }

}