using System;
using System.Collections.Generic;
using static PKHeX.Core.LegalityCheckStrings;

namespace PKHeX.Core
{
    /// <summary>
    /// Default formatter for Legality Result displays.
    /// </summary>
    public sealed class BaseLegalityFormatter : ILegalityFormatter
    {
        public string GetReport(LegalityAnalysis l)
        {
            if (l.Valid)
                return L_ALegal;
            if (!l.Parsed)
                return L_AnalysisUnavailable;

            var lines = GetLegalityReportLines(l);
            return string.Join(Environment.NewLine, lines);
        }

        public string GetReportVerbose(LegalityAnalysis l)
        {
            if (!l.Parsed)
                return L_AnalysisUnavailable;

            var lines = GetVerboseLegalityReportLines(l);
            return string.Join(Environment.NewLine, lines);
        }

        private static List<string> GetLegalityReportLines(LegalityAnalysis l)
        {
            var lines = new List<string>();
            var info = l.Info;
            var pkm = l.pkm;

            LegalityFormatting.AddMoves(info.Moves, lines, pkm.Format, false);
            if (pkm.Format >= 6)
                LegalityFormatting.AddRelearn(info.Relearn, lines, false);
            LegalityFormatting.AddSecondaryChecksInvalid(l.Results, lines);
            return lines;
        }

        private static IReadOnlyList<string> GetVerboseLegalityReportLines(LegalityAnalysis l)
        {
            var lines = l.Valid ? new List<string> {L_ALegal} : GetLegalityReportLines(l);
            var info = l.Info;
            var pkm = l.pkm;
            const string separator = "===";
            lines.Add(separator);
            lines.Add(string.Empty);
            int initialCount = lines.Count;

            var format = pkm.Format;
            LegalityFormatting.AddMoves(info.Moves, lines, format, true);

            if (format >= 6)
                LegalityFormatting.AddRelearn(info.Relearn, lines, true);

            if (lines.Count != initialCount) // move info added, break for next section
                lines.Add(string.Empty);

            LegalityFormatting.AddSecondaryChecksValid(l.Results, lines);

            lines.Add(separator);
            lines.Add(string.Empty);
            LegalityFormatting.AddEncounterInfo(l, lines);

            return lines;
        }
    }
}