using System;

namespace SourceGit.Models
{
    public enum ChangeViewMode
    {
        List,
        Grid,
        Tree,
    }

    public enum ChangeState
    {
        None,
        Modified,
        TypeChanged,
        Added,
        Deleted,
        Renamed,
        Copied,
        Untracked,
        Conflicted,
    }

    public enum ConflictReason
    {
        None,
        BothDeleted,
        AddedByUs,
        DeletedByThem,
        AddedByThem,
        DeletedByUs,
        BothAdded,
        BothModified,
    }

    public class ChangeDataForAmend
    {
        public string FileMode { get; set; } = "";
        public string ObjectHash { get; set; } = "";
        public string ParentSHA { get; set; } = "";
    }

    public class Change
    {
        public ChangeState Index { get; set; } = ChangeState.None;
        public ChangeState WorkTree { get; set; } = ChangeState.None;
        public string Path { get; set; } = "";
        public string OriginalPath { get; set; } = "";
        public ChangeDataForAmend DataForAmend { get; set; } = null;
        public ConflictReason ConflictReason { get; set; } = ConflictReason.None;

        public bool IsConflicted => WorkTree == ChangeState.Conflicted;
        public string ConflictMarker => CONFLICT_MARKERS[(int)ConflictReason];
        public string ConflictDesc => CONFLICT_DESCS[(int)ConflictReason];
        
        public string WorkTreeDesc => TYPE_DESCS[(int)WorkTree];
        public string IndexDesc => TYPE_DESCS[(int)Index];

        public void Set(ChangeState index, ChangeState workTree = ChangeState.None)
        {
            Index = index;
            WorkTree = workTree;

            if (index == ChangeState.Renamed || workTree == ChangeState.Renamed)
            {
                var idx = Path.IndexOf('\t', StringComparison.Ordinal);
                if (idx >= 0)
                {
                    OriginalPath = Path.Substring(0, idx);
                    Path = Path.Substring(idx + 1);
                }
                else
                {
                    idx = Path.IndexOf(" -> ", StringComparison.Ordinal);
                    if (idx > 0)
                    {
                        OriginalPath = Path.Substring(0, idx);
                        Path = Path.Substring(idx + 4);
                    }
                }
            }

            if (Path[0] == '"')
                Path = Path.Substring(1, Path.Length - 2);

            if (!string.IsNullOrEmpty(OriginalPath) && OriginalPath[0] == '"')
                OriginalPath = OriginalPath.Substring(1, OriginalPath.Length - 2);
        }
        
        private static readonly string[] TYPE_DESCS = 
        [
            "Unknown",
            "Modified",
            "Type Changed",
            "Added", 
            "Deleted", 
            "Renamed", 
            "Copied", 
            "Untracked", 
            "Conflict"
        ];
        private static readonly string[] CONFLICT_MARKERS =
        [
            string.Empty,
            "DD",
            "AU",
            "UD",
            "UA",
            "DU",
            "AA",
            "UU"
        ];
        private static readonly string[] CONFLICT_DESCS =
        [
            string.Empty,
            "Both deleted",
            "Added by us",
            "Deleted by them",
            "Added by them",
            "Deleted by us",
            "Both added",
            "Both modified"
        ];
    }
}