using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
using Npgsql;
using System.Collections.Generic;
using download_admin;

namespace download_admin.Pages;

public class IndexModel : PageModel
{
    private readonly ILogger<IndexModel> _logger;

    public IndexModel(ILogger<IndexModel> logger)
    {
        _logger = logger;
    }

    public void OnGet()
    {
        ViewData["Title"] = "Download Repsoitory Editor";
        LoadData();
    }

    public void OnPost()
    {
        ViewData["Title"] = "Download Repsoitory Editor";

        if (!String.IsNullOrEmpty(Request.Form["add"]))
        {
            DoAdd();
        }
        else if (!String.IsNullOrEmpty(Request.Form["delete"]))
        {
            DoDelete();
        }
        else if (!String.IsNullOrEmpty(Request.Form["update"]))
        {
            DoUpdate();
        }

        LoadData();
    }


    public List<FileObject>? Rows {get;private set;}

    public bool HasError {get; private set;}

    public string? ErrorText {get; private set;}

    private void DoAdd()
    {
        try
        {
            string? key = Request.Form["key"];
            string? mime_type = Request.Form["mime_type"];
            string? file_name = Request.Form["file_name"];
            IFormFile? file = Request.Form.Files.Count > 0 ? Request.Form.Files[0] : null;

            if (String.IsNullOrWhiteSpace(key) ||
                String.IsNullOrWhiteSpace(mime_type) ||
                String.IsNullOrEmpty(file_name) ||
                file == null)
            {
                SetError("Need key, mime type, file name and file");
                return;
            }

            using var file_stream = file.OpenReadStream();
            byte[] file_data = new byte[file.Length];
            file_stream.Read(file_data, 0, (int)file.Length);

            using var conn = new NpgsqlConnection(Config.Settings["ConnectionStrings:download"]);

            conn.Open();

            using var cmd = new NpgsqlCommand("INSERT INTO file_object (key, mime_type, file_name, data) VALUES (@key, @mime_type, @file_name, @data)", conn);

            cmd.Parameters.AddWithValue("key", NpgsqlTypes.NpgsqlDbType.Varchar, key);
            cmd.Parameters.AddWithValue("mime_type", NpgsqlTypes.NpgsqlDbType.Varchar, mime_type);
            cmd.Parameters.AddWithValue("file_name", NpgsqlTypes.NpgsqlDbType.Varchar, file_name);
            cmd.Parameters.AddWithValue("data", NpgsqlTypes.NpgsqlDbType.Bytea, file_data);

            cmd.ExecuteNonQuery();
        }
        catch(Exception e)
        {
            SetError(e.Message);
        }
    }

    private void DoDelete()
    {
        try
        {
            string? key = Request.Form["original_key"];
  
            using var conn = new NpgsqlConnection(Config.Settings["ConnectionStrings:download"]);

            conn.Open();

            using var delete_download = new NpgsqlCommand("DELETE FROM download WHERE key = @original_key", conn);

            delete_download.Parameters.AddWithValue("original_key", NpgsqlTypes.NpgsqlDbType.Varchar, key);
            delete_download.ExecuteNonQuery();

            using var delete_file = new NpgsqlCommand("DELETE FROM file_object WHERE key = @original_key", conn);

            delete_file.Parameters.AddWithValue("original_key", NpgsqlTypes.NpgsqlDbType.Varchar, key);
            delete_file.ExecuteNonQuery();
        }
        catch(Exception e)
        {
            SetError(e.Message);
        }
    }

    private void DoUpdate()
    {
        try
        {
            string? original_key = Request.Form["original_key"];
            string? key = Request.Form["key"];
            string? mime_type = Request.Form["mime_type"];
            string? file_name = Request.Form["file_name"];
            IFormFile? file = Request.Form.Files.Count > 0 ? Request.Form.Files[0] : null;

            if (file != null)
            {
                using var file_stream = file.OpenReadStream();
                byte[] file_data = new byte[file.Length];
                file_stream.Read(file_data, 0, (int)file.Length);

                using var conn = new NpgsqlConnection(Config.Settings["ConnectionStrings:download"]);

                conn.Open();

                using var cmd = new NpgsqlCommand("UPDATE file_object set key=@key, mime_type=@mime_type, file_name=@file_name, data=@data WHERE key=@original_key", conn);

                cmd.Parameters.AddWithValue("original_key", NpgsqlTypes.NpgsqlDbType.Varchar, original_key);
                cmd.Parameters.AddWithValue("key", NpgsqlTypes.NpgsqlDbType.Varchar, key);
                cmd.Parameters.AddWithValue("mime_type", NpgsqlTypes.NpgsqlDbType.Varchar, mime_type);
                cmd.Parameters.AddWithValue("file_name", NpgsqlTypes.NpgsqlDbType.Varchar, file_name);
                cmd.Parameters.AddWithValue("data", NpgsqlTypes.NpgsqlDbType.Bytea, file_data);

                cmd.ExecuteNonQuery();
            }
            else
            {
                using var conn = new NpgsqlConnection(Config.Settings["ConnectionStrings:download"]);

                conn.Open();

                using var cmd = new NpgsqlCommand("UPDATE file_object set key=@key, mime_type=@mime_type, file_name=@file_name WHERE key=@original_key", conn);

                cmd.Parameters.AddWithValue("original_key", NpgsqlTypes.NpgsqlDbType.Varchar, original_key);
                cmd.Parameters.AddWithValue("key", NpgsqlTypes.NpgsqlDbType.Varchar, key);
                cmd.Parameters.AddWithValue("mime_type", NpgsqlTypes.NpgsqlDbType.Varchar, mime_type);
                cmd.Parameters.AddWithValue("file_name", NpgsqlTypes.NpgsqlDbType.Varchar, file_name);

                cmd.ExecuteNonQuery();
            }

        }
        catch(Exception e)
        {
            SetError(e.Message);
        }
    }

    private void LoadData()
    {
        try
        {
            Rows = new List<FileObject>();

            using var conn = new NpgsqlConnection(Config.Settings["ConnectionStrings:download"]);

            conn.Open();

            using var cmd = new NpgsqlCommand("SELECT key, mime_type, file_name, data FROM file_object ORDER BY key", conn);
            using var reader = cmd.ExecuteReader();
            
            while(reader.Read())
            {
                string key = (string)reader["key"];
                string mime_type = (string)reader["mime_type"];
                string file_name = (string)reader["file_name"];
                byte[] data = (byte[])reader["data"];

                Rows.Add(new FileObject(key, mime_type, file_name, data));
            }
        }
        catch(Exception e)
        {
            SetError(e.Message);
        }
    }

    private void SetError(string error_text)
    {
        HasError = true;
        ErrorText = error_text;
    }
}