using System.Collections.Generic;
using System.IO;
using System.Linq;
using Learn.Models;
using Learn.Parsers;

namespace Learn;

public class FileMover(string targetPath, bool preview)
{
    private readonly HashSet<TreeNode> _visited = new ();

    private string NumToString(int n)
    {
        if (n < 10) return "0" + n;
        return n.ToString();
    }

    private bool TryGetPath(TreeNode node, out string path)
    {
        path = null;
        if (!node.TryGetValue(ItemFields.Key_Title, out var title, out _)) return false;
        if (!node.TryGetValue(ItemFields.Key_Season, out var season, out _)) return false;
        if (!node.TryGetValue(ItemFields.Key_Year, out var year, out _)) return false;

        path = $"{title} ({year})/";

        
        if (node.TryGetValue(ItemFields.Key_SeasonOffsetBase, out var seasonBase, out _))
        {
            season = seasonBase;
        }
        
        if (int.TryParse(season, out var seasonNum))
        {
            path += $"Season {seasonNum}";
        }
        else
        {
            path += season;
        }
        
        return true;
    }
    
    private void MoveFile(TreeNode node)
    {
        var path = node.Info.MainInfo[ItemFields.MainKey_Path];

        if (!node.TryGetValue(ItemFields.Key_Type, out var type, out _)) return;
        if (!node.TryGetValue(ItemFields.Key_Title, out var title, out _)) return;
        if (!node.TryGetValue(ItemFields.Key_Episode, out var episode, out _)) return;
        if (!node.TryGetValue(ItemFields.Key_Season, out var season, out _)) return;
        if (!node.TryGetValue(ItemFields.Key_Year, out var year, out _)) return;
        if (!TryGetPath(node, out var relativePath)) return;
        
        var filenameParts = new List<string>();
        var metaParts = new List<string>();
        filenameParts.Add(title);
        filenameParts.Add($"({year})");

        var seasonAndEpisodePart = "";
        
        if (node.TryGetValue(ItemFields.Key_SeasonOffsetBase, out var seasonBase, out _))
        {
            season = seasonBase;
        }
        if (int.TryParse(season, out var seasonNum))
        {
            seasonAndEpisodePart += $"S{NumToString(seasonNum)}";
        }

        if (!node.TryGetValue(ItemFields.Key_EpisodeOffset, out var episodeOffset, out _) || !int.TryParse(episodeOffset, out var episodeOffsetNum))
        {
            episodeOffsetNum = 0;
        }
        var episodeNum = int.Parse(episode) + episodeOffsetNum;
        seasonAndEpisodePart += $"E{NumToString(episodeNum)}";
        filenameParts.Add(seasonAndEpisodePart);

        if (node.TryGetValue(ItemFields.Key_Group, out var group, out _))
        {
            metaParts.Add(group);
        }

        if (node.TryGetValue(ItemFields.Key_TMDBID, out var tmdbid, out _))
        {
            metaParts.Add($"tmdbid-{tmdbid}");
        }

        if (node.TryGetValue(ItemFields.Key_ExtraMeta, out var extraMeta, out _))
        {
            metaParts.Add(extraMeta);
        }
        
        var filename = string.Join(" ", string.Join(" ", filenameParts), string.Join("", metaParts.Select(part => $"[{part}]")));
        
        if (type == ItemFields.ItemType.Subtitle.ToString())
        {
            if (node.TryGetValue(ItemFields.Key_SubtitleLanguage, out var subLang, out _))
            {
                filename += "." + subLang;
            }
        }
        
        filename += Path.GetExtension(path);
        
        var target = string.Join("/", targetPath, relativePath, filename);
        MoveIt(node, target);
    }

    private void MoveExtra(TreeNode node)
    {
        if (!TryGetPath(node, out var relativePath)) return;
        if (!node.TryGetValue(ItemFields.Key_Season, out var season, out _)) return;
        
        var path = node.Info.MainInfo[ItemFields.MainKey_Path];
        var name = Path.GetFileName(path);
        var target = string.Join("/", targetPath, relativePath, "extras", $"Season {season}", name);
        MoveIt(node, target);
    }

    private void MoveIt(TreeNode node, string targetPath)
    {
        node.Info.Info["TargetPath"] = targetPath;
        if (preview) return;
        var path = node.Info.MainInfo[ItemFields.MainKey_Path];
        if (File.Exists(targetPath)) return;
        if (Directory.Exists(path))
        {
            Directory.CreateDirectory(Path.GetDirectoryName(targetPath));
            Directory.Move(path, targetPath);
        }
        else
        {
            Directory.CreateDirectory(Path.GetDirectoryName(targetPath));
            File.Move(path, targetPath);
        }
    }
    
    public void DoMove(TreeNode node)
    {
        if (_visited.Contains(node)) return;
        
        string type;
        if (!node.TryGetValue(ItemFields.Key_Type, out type, out _))
        {
            type = ItemFields.ItemType.Unknown.ToString();
        }
        
        if (type == ItemFields.ItemType.Extra.ToString())
        {
            MoveExtra(node);
            _visited.Add(node);
            return;
        }
        
        if (node.Info.IsFolder())
        {
            foreach (var child in node.Children)
            {
                DoMove(child);
            }
        } 
        else
        {
            MoveFile(node);
        }
        
        _visited.Add(node);
    }
}