using System.Collections.ObjectModel;
using System.Globalization;
using System.Text;
using System.Text.RegularExpressions;

namespace View_by_Distance.Shared.Models.Stateless.Methods;

internal abstract class MarkDown
{

    // ...

    internal static List<string> GetFrontMatter(long ticks, string fullName, string lowerHyphenFullName, Models.GenealogicalDataCommunication genealogicalDataCommunication)
    {
        List<string> results = new();
        string afterTrim;
        string[] jsonLines = genealogicalDataCommunication.ToString().Split(Environment.NewLine);
        foreach (string jsonLine in jsonLines)
        {
            afterTrim = jsonLine.Trim();
            if (afterTrim.Length < 3)
                continue;
            if (afterTrim[^1] != ',')
                results.Add(afterTrim[1..].Replace("\": \"", ": \""));
            else
                results.Add(afterTrim[1..^1].Replace("\": \"", ": \""));
        }
        if (results.Any())
        {
            DateTime dateTime = new DateTime(ticks).ToUniversalTime();
            results.Insert(0, $"updated: \"{dateTime:yyyy-MM-ddTHH:mm:ss.fffZ}\"");
            results.Insert(0, $"created: \"{dateTime:yyyy-MM-ddTHH:mm:ss.fffZ}\"");
            results.Insert(0, $"title: \"{fullName}\"");
            results.Insert(0, "type: \"person\"");
            results.Add("draft: false");
            results.Insert(0, "---");
            results.Add($"{nameof(lowerHyphenFullName)}: \"{lowerHyphenFullName}\"");
            results.Add("---");
        }
        return results;
    }

    internal static void WriteFile(string personKeyFormatted, long ticks, List<GenealogicalDataCommunicationRelation> genealogicalDataCommunicationRelations, string a2PeopleContentDirectory, Calendar calendar, string pattern, ReadOnlyDictionary<string, string> personKeyFormattedToPersonFullName, ReadOnlyDictionary<int, List<GenealogicalDataCommunicationRelation>> familyIndexToCollection, Models.GenealogicalDataCommunication genealogicalDataCommunication, string fullName, string lowerHyphenFullName, List<string> frontMatter)
    {
        string decade;
        string? personFullName;
        const char father = 'F';
        const char mother = 'M';
        bool hasRelation = false;
        const string wife = "WIFE";
        List<string> lines = new();
        StringBuilder link = new();
        const string child = "CHIL";
        const string husband = "HUSB";
        const string person = "person";
        DateTime dateTime = new(ticks);
        List<GenealogicalDataCommunicationRelation>? relations;
        lines.AddRange(frontMatter);
        lines.Add(string.Empty);
        lines.Add($"# {fullName}");
        lines.Add(string.Empty);
        foreach (GenealogicalDataCommunicationRelation genealogicalDataCommunicationRelation in genealogicalDataCommunicationRelations)
        {
            if (genealogicalDataCommunication?.NickName is null || genealogicalDataCommunication.NickName.Length < 4)
                continue;
            if (genealogicalDataCommunicationRelation.Relation != child)
                continue;
            if (genealogicalDataCommunicationRelation.NickName != personKeyFormatted)
                continue;
            if (!familyIndexToCollection.TryGetValue(genealogicalDataCommunicationRelation.FamilyIndex, out relations))
                continue;
            foreach (GenealogicalDataCommunicationRelation relation in relations)
            {
                if (relation.FamilyIndex != genealogicalDataCommunicationRelation.FamilyIndex)
                    continue;
                if (relation.Relation is husband or wife)
                {
                    if (!hasRelation)
                    {
                        lines.Add("## Relations");
                        lines.Add(string.Empty);
                        hasRelation = true;
                    }
                    decade = relation.NickName[..3];
                    _ = link.Clear();
                    _ = link.Append("- [");
                    if (!personKeyFormattedToPersonFullName.TryGetValue(relation.NickName, out personFullName))
                        _ = link.Append(relation.NickName);
                    else
                        _ = link.Append(personFullName);
                    if (genealogicalDataCommunication.NickName[..3] == decade)
                        _ = link.Append("](");
                    else
                        _ = link.Append("](../").Append(decade).Append('/');
                    if (personFullName is null)
                        _ = link.Append(relation.NickName);
                    else
                        _ = link.Append(Regex.Replace(personFullName.ToLower(), pattern, "-").Replace("--", "-"));
                    _ = link.Append(".md) ");
                    if (string.IsNullOrEmpty(genealogicalDataCommunicationRelation.LineTwo))
                        lines.Add(link.ToString());
                    else
                    {
                        if (genealogicalDataCommunicationRelation.LineTwo[1] == father)
                        {
                            if (relation.Relation == wife)
                                _ = link.Append(nameof(mother));
                            else if (relation.Relation == husband)
                                _ = link.Append(genealogicalDataCommunicationRelation.LineTwo.Split(' ').Last()).Append(nameof(father));
                        }
                        else if (genealogicalDataCommunicationRelation.LineTwo[1] == mother)
                        {
                            if (relation.Relation == husband)
                                _ = link.Append(nameof(father));
                            else if (relation.Relation == wife)
                                _ = link.Append(genealogicalDataCommunicationRelation.LineTwo.Split(' ').Last()).Append(nameof(mother));
                        }
                        lines.Add(link.ToString());
                    }
                }
            }
        }
        if (hasRelation)
            lines.Add(string.Empty);
        string text = string.Join(Environment.NewLine, lines);
        string weekOfYear = calendar.GetWeekOfYear(dateTime, CalendarWeekRule.FirstDay, DayOfWeek.Sunday).ToString("00");
        string directory = Path.Combine(a2PeopleContentDirectory, $"{dateTime.Year}-Markdown", $"{dateTime.Year}-Week-{weekOfYear}", ticks.ToString(), person, personKeyFormatted[..3]);
        if (!Directory.Exists(directory))
            _ = Directory.CreateDirectory(directory);
        _ = IPath.WriteAllText(Path.Combine(directory, $"{lowerHyphenFullName}.md"), text, updateDateWhenMatches: false, compareBeforeWrite: true);
    }

}