#region License
/* 
 * Copyright (C) 1999-2022 John Källén.
 .
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; see the file COPYING.  If not, write to
 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 */
#endregion

using Moq;
using NUnit.Framework;
using Reko.Core;
using Reko.Core.Expressions;
using Reko.Core.Graphs;
using Reko.Core.Memory;
using Reko.Core.Rtl;
using Reko.Core.Types;
using Reko.Scanning;
using Reko.UnitTests.Mocks;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;

namespace Reko.UnitTests.Decompiler.Scanning
{
    public class AbstractScannerTests
    {
        protected Mock<IProcessorArchitecture> arch = default!;
        protected Mock<IPlatform> platform = default!;
        protected Program program = default!;
        protected Identifier r1;
        protected Identifier r2;
        protected RegisterStorage sr;
        protected Identifier C;

        public AbstractScannerTests()
        {
            this.r1 = Identifier.Create(new RegisterStorage("r1", 1, 0, PrimitiveType.Word32));
            this.r2 = Identifier.Create(new RegisterStorage("r2", 2, 0, PrimitiveType.Word32));
            this.sr = new RegisterStorage("SR", 42, 0, PrimitiveType.Word32);
            this.C = Identifier.Create(new FlagGroupStorage(sr, 1, "C", PrimitiveType.Bool));
        }

        protected void Setup(int textSize, int instrBitSize)
        {
            this.arch = new Mock<IProcessorArchitecture>();
            this.platform = new Mock<IPlatform>();

            arch.Setup(a => a.Name).Returns("FakeCpu");
            arch.Setup(a => a.InstructionBitSize).Returns(instrBitSize);
            arch.Setup(a => a.MemoryGranularity).Returns(8);
            arch.Setup(a => a.Endianness).Returns(EndianServices.Little);
            arch.Setup(a => a.PointerType).Returns(PrimitiveType.Ptr32);
            arch.Setup(a => a.CreateProcessorState())
                .Returns(new Func<ProcessorState>(() => new FakeProcessorState(arch.Object)));
            arch.Setup(a => a.CreateImageReader(
                It.IsNotNull<MemoryArea>(),
                It.IsNotNull<Address>()))
                .Returns(new Func<MemoryArea, Address, EndianImageReader>((mm, aa) =>
                    mm.CreateLeReader(aa)));
            arch.Setup(a => a.MakeAddressFromConstant(
                It.IsNotNull<Constant>(),
                It.IsAny<bool>()))
                .Returns(new Func<Constant, bool, Address>((c, a) =>
                    Address.Ptr32(c.ToUInt32())));

            platform.Setup(p => p.Architecture).Returns(arch.Object);

            var segmentMap = new SegmentMap(
                new ImageSegment(
                    ".text",
                    new ByteMemoryArea(Address.Ptr32(0x1000), new byte[textSize]),
                    AccessMode.ReadExecute),
                new ImageSegment(
                    ".data",
                    new ByteMemoryArea(Address.Ptr32(0x3000), new byte[4096]),
                    AccessMode.ReadWrite));

            this.program = new Program
            {
                SegmentMap = segmentMap,
                Architecture = arch.Object,
                Platform = platform.Object,
            };
        }

        protected void DumpBlock(RtlBlock block, CfgGraph g, TextWriter w)
        {
            w.WriteLine("{0}: // l:{1}; ft:{2}{3}",
                block.Name, block.Length, block.FallThrough, block.IsValid ? "" : " (INVALID)");
            w.Write("    // pred:");
            foreach (var s in g.Predecessors(block))
            {
                w.Write(" {0}", s.Name);
            }
            w.WriteLine();

            foreach (var cluster in block.Instructions)
            {
                foreach (var instr in cluster.Instructions)
                {
                    w.WriteLine("    {0}", instr);
                }
            }
            w.Write("    // succ:");
            foreach (var s in g.Successors(block))
            {
                w.Write(" {0}", s.Name);
            }
            w.WriteLine();
        }

        protected void Given_EntryPoint(uint uAddr)
        {
            var addr = Address.Ptr32(uAddr);
            var sym = ImageSymbol.Procedure(arch.Object, addr);
            this.program.EntryPoints.Add(addr, sym);
        }

        protected void Given_JumpTable(uint uAddrTable, params uint[] entries)
        {
            var addrTable = Address.Ptr32(uAddrTable);
            if (!program.SegmentMap.TryFindSegment(addrTable, out var segment))
                Assert.Fail($"No segment available for {uAddrTable:X8}");
            var mem = segment.MemoryArea;
            var writer = program.Architecture.Endianness.CreateImageWriter(mem, addrTable);
            foreach (var uEntry in entries)
            {
                writer.WriteUInt32(uEntry);
            }
        }

        protected void Given_Trace(RtlTrace trace)
        {
            arch.Setup(a => a.CreateRewriter(
                It.Is<EndianImageReader>(r => r.Address == trace.StartAddress),
                It.IsNotNull<ProcessorState>(),
                It.IsNotNull<IStorageBinder>(),
                It.IsNotNull<IRewriterHost>()))
                .Returns(trace);
        }

        protected void Given_TrampolineAt(uint uAddrBegin, uint uAddrLast, string impProcName)
        {
            var addrBegin = Address.Ptr32(uAddrBegin);
            var addrLast = Address.Ptr32(uAddrLast);
            var proc = new ExternalProcedure(impProcName, FunctionType.Action());
            var trampoline = new Trampoline(addrBegin, proc);
            platform.Setup(p => p.GetTrampolineDestination(
                addrLast,
                It.IsNotNull<List<RtlInstructionCluster>>(),
                It.IsNotNull<IRewriterHost>())).Returns(trampoline);
        }

        protected void Given_ImageSymbol_Proc(uint uAddr, string name)
        {
            var imgsym = ImageSymbol.Procedure(arch.Object, Address.Ptr32(uAddr), name);
            program.ImageSymbols.Add(imgsym.Address, imgsym);
        }

        protected class CfgGraph : DirectedGraph<RtlBlock>
        {
            private ScanResultsV2 cfg;

            public CfgGraph(ScanResultsV2 cfg)
            {
                this.cfg = cfg;
            }

            public ICollection<RtlBlock> Nodes => cfg.Blocks.Values;

            public void AddEdge(RtlBlock nodeFrom, RtlBlock nodeTo)
            {
                throw new NotImplementedException();
            }

            public bool ContainsEdge(RtlBlock nodeFrom, RtlBlock nodeTo)
            {
                throw new NotImplementedException();
            }

            public ICollection<RtlBlock> Predecessors(RtlBlock node)
            {
                return cfg.Predecessors.TryGetValue(node.Address, out var preds)
                    ? preds
                        .Select(e => cfg.Blocks[e])
                        .ToArray()
                    : Array.Empty<RtlBlock>();
            }

            public void RemoveEdge(RtlBlock nodeFrom, RtlBlock nodeTo)
            {
                throw new NotImplementedException();
            }

            public ICollection<RtlBlock> Successors(RtlBlock node)
            {
                return cfg.Successors.TryGetValue(node.Address, out var succs)
                    ? succs
                        .Select(s => Get(s))
                        .ToArray()
                    : Array.Empty<RtlBlock>();
            }

            private RtlBlock Get(Address e)
            {
                var b = cfg.Blocks[e];
                return b;
            }
        }
    }
}