using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq.Expressions;
using AspClassic.Scripting.Runtime;
using AspClassic.Scripting.Utils;

namespace AspClassic.Scripting;

[DebuggerDisplay("{_path ?? \"<anonymous>\"}")]
public sealed class SourceUnit
{
	private class KeyComparer<T1> : IComparer<KeyValuePair<int, T1>>
	{
		public int Compare(KeyValuePair<int, T1> x, KeyValuePair<int, T1> y)
		{
			return x.Key - y.Key;
		}
	}

	private readonly SourceCodeKind _kind;

	private readonly string _path;

	private readonly LanguageContext _language;

	private readonly TextContentProvider _contentProvider;

	private ScriptCodeParseResult? _parseResult;

	private KeyValuePair<int, int>[] _lineMap;

	public string Path => _path;

	public bool HasPath => _path != null;

	public SourceCodeKind Kind => _kind;

	public SymbolDocumentInfo Document
	{
		get
		{
			if (_path != null)
			{
				return Expression.SymbolDocument(_path, _language.LanguageGuid, _language.VendorGuid);
			}
			return null;
		}
	}

	public LanguageContext LanguageContext => _language;

	public ScriptCodeParseResult? CodeProperties
	{
		get
		{
			return _parseResult;
		}
		set
		{
			_parseResult = value;
		}
	}

	public bool EmitDebugSymbols
	{
		get
		{
			if (HasPath)
			{
				return LanguageContext.DomainManager.Configuration.DebugMode;
			}
			return false;
		}
	}

	public ScriptCodeParseResult GetCodeProperties()
	{
		return GetCodeProperties(_language.GetCompilerOptions());
	}

	public ScriptCodeParseResult GetCodeProperties(CompilerOptions options)
	{
		ContractUtils.RequiresNotNull(options, "options");
		_language.CompileSourceCode(this, options, ErrorSink.Null);
		return _parseResult ?? ScriptCodeParseResult.Complete;
	}

	public SourceUnit(LanguageContext context, TextContentProvider contentProvider, string path, SourceCodeKind kind)
	{
		_language = context;
		_contentProvider = contentProvider;
		_kind = kind;
		_path = path;
	}

	public SourceCodeReader GetReader()
	{
		return _contentProvider.GetReader();
	}

	public string[] GetCodeLines(int start, int count)
	{
		ContractUtils.Requires(start > 0, "start");
		ContractUtils.Requires(count > 0, "count");
		List<string> list = new List<string>(count);
		using (SourceCodeReader sourceCodeReader = GetReader())
		{
			sourceCodeReader.SeekLine(start);
			while (count > 0)
			{
				string text = sourceCodeReader.ReadLine();
				if (text != null)
				{
					list.Add(text);
					count--;
					continue;
				}
				break;
			}
		}
		return list.ToArray();
	}

	public string GetCodeLine(int line)
	{
		string[] codeLines = GetCodeLines(line, 1);
		if (codeLines.Length <= 0)
		{
			return null;
		}
		return codeLines[0];
	}

	public string GetCode()
	{
		using SourceCodeReader sourceCodeReader = GetReader();
		return sourceCodeReader.ReadToEnd();
	}

	public SourceLocation MakeLocation(int index, int line, int column)
	{
		return new SourceLocation(index, MapLine(line), column);
	}

	public SourceLocation MakeLocation(SourceLocation loc)
	{
		return new SourceLocation(loc.Index, MapLine(loc.Line), loc.Column);
	}

	public int MapLine(int line)
	{
		if (_lineMap != null)
		{
			int num = BinarySearch(_lineMap, line);
			int num2 = line - _lineMap[num].Key;
			line = _lineMap[num].Value + num2;
			if (line < 1)
			{
				line = 1;
			}
		}
		return line;
	}

	private static int BinarySearch<T>(KeyValuePair<int, T>[] array, int line)
	{
		int num = Array.BinarySearch(array, new KeyValuePair<int, T>(line, default(T)), new KeyComparer<T>());
		if (num < 0)
		{
			num = ~num - 1;
			if (num == -1)
			{
				num = 0;
			}
		}
		return num;
	}

	public ScriptCode Compile()
	{
		return Compile(ErrorSink.Default);
	}

	public ScriptCode Compile(ErrorSink errorSink)
	{
		return Compile(_language.GetCompilerOptions(), errorSink);
	}

	public ScriptCode Compile(CompilerOptions options, ErrorSink errorSink)
	{
		ContractUtils.RequiresNotNull(errorSink, "errorSink");
		ContractUtils.RequiresNotNull(options, "options");
		return _language.CompileSourceCode(this, options, errorSink);
	}

	public object Execute(Scope scope)
	{
		return Execute(scope, ErrorSink.Default);
	}

	public object Execute(Scope scope, ErrorSink errorSink)
	{
		ContractUtils.RequiresNotNull(scope, "scope");
		ScriptCode scriptCode = Compile(_language.GetCompilerOptions(scope), errorSink);
		if (scriptCode == null)
		{
			throw new SyntaxErrorException();
		}
		return scriptCode.Run(scope);
	}

	public object Execute()
	{
		return Compile().Run();
	}

	public object Execute(ErrorSink errorSink)
	{
		return Compile(errorSink).Run();
	}

	public object Execute(CompilerOptions options, ErrorSink errorSink)
	{
		return Compile(options, errorSink).Run();
	}

	public int ExecuteProgram()
	{
		return _language.ExecuteProgram(this);
	}

	public void SetLineMapping(KeyValuePair<int, int>[] lineMap)
	{
		_lineMap = ((lineMap == null || lineMap.Length == 0) ? null : lineMap);
	}
}