using Microsoft.SqlServer.TransactSql.ScriptDom;
using SQLLinter.Common;
using SQLLinter.Core;
using SQLLinter.Core.Interfaces;
using SQLLinter.Infrastructure.Configuration.Overrides;
using SQLLinter.Infrastructure.Interfaces;

namespace SQLLinter.Infrastructure.Parser;

public class FragmentBuilder : IFragmentBuilder
{
    private readonly TSqlParser parser;
    private readonly IReporter _reporter;

    public FragmentBuilder(IReporter reporter) : this(reporter, Constants.DefaultCompatabilityLevel)
    {
    }

    public FragmentBuilder(IReporter reporter, int compatabilityLevel)
    {
        parser = GetSqlParser(compatabilityLevel);
        _reporter = reporter;
    }

    public TSqlFragment? GetFragment(string path, TextReader txtRdr, out IList<ParseError> errors, IEnumerable<IOverride> overrides = null)
    {
        TSqlFragment fragment;

        OverrideCompatabilityLevel? compatibilityLevel = null;
        if (overrides != null)
        {
            foreach (var lintingOverride in overrides)
            {
                if (lintingOverride is OverrideCompatabilityLevel overrideCompatability)
                {
                    compatibilityLevel = overrideCompatability;
                }
            }
        }

        TSqlParser curParser;

        if (compatibilityLevel != null)
        {
            curParser = GetSqlParser(compatibilityLevel.CompatabilityLevel);
        }
        else
        {
            curParser = parser;
        }

        fragment = curParser.Parse(txtRdr, out errors); //TODO: Возвращать эти ошибки

        if (fragment == null)
        {
            foreach (var err in errors)
            {
                _reporter.ReportViolation(path, err.Line, err.Column, RuleViolationSeverity.Critical, "parse", err.Message);
            }
        }

        return fragment?.FirstTokenIndex != -1 ? fragment : null;
    }

    private static TSqlParser GetSqlParser(int compatabilityLevel)
    {
        TSqlParser parser = compatabilityLevel switch
        {
            80 => new TSql80Parser(true),
            90 => new TSql90Parser(true),
            100 => new TSql100Parser(true),
            110 => new TSql110Parser(true),
            120 => new TSql120Parser(true),
            130 => new TSql130Parser(true),
            140 => new TSql140Parser(true),
            150 => new TSql150Parser(true),
            160 => new TSql160Parser(true),
            170 => new TSql170Parser(true),
            _ => new TSql120Parser(true),
        };

        return parser;
    }
}