using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Xml.Linq;


namespace CreateMSBuildProject
{
    /// <summary>Encapsulates a ".csproj" file.</summary>

    sealed class CSProj
    {
        /// <summary>Encapsulates information about a particular build configuration.</summary>

        public sealed class BuildConfiguration
        {
            public BuildConfiguration(XElement configuration)
            {
                // ReSharper disable PossibleNullReferenceException

                OutputPath = configuration.Element(_ns + "OutputPath").Value;
                //WarningLevel = warningLevel(configuration);
                //CodeAnalysisRuleset = configuration.Element(_ns + "CodeAnalysisRuleSet").Value;
                //TreatWarningsAsErrors = isTrue(configuration.Element(_ns + "TreatWarningsAsErrors"));
                //IsCodeAnalysisEnabled = isTrue(configuration.Element(_ns + "RunCodeAnalysis"));
                //IsCodeContractsEnabled = isTrue(configuration.Element(_ns + "CodeContractsEnableRuntimeChecking"));

                // ReSharper restore PossibleNullReferenceException
            }

            public bool IsDebug
            {
                get
                {
                    return (string.Compare(OutputPath, "bin\\debug\\", StringComparison.OrdinalIgnoreCase) == 0);
                }
            }

            public bool IsRelease
            {
                get
                {
                    return (string.Compare(OutputPath, "bin\\release\\", StringComparison.OrdinalIgnoreCase) == 0);
                }
            }

            static bool isTrue(XElement element) // Defaults to false if element is null.
            {
                return (element != null) && (string.Compare(element.Value, "true", StringComparison.OrdinalIgnoreCase) == 0);
            }

            static int warningLevel(XElement element) // Defaults to 4 if not set.
            {
                var level = element.Element(_ns + "WarningLevel");

                if (level != null)
                    return int.Parse(level.Value);
                else
                    return 4; // Default warning level is 4.
            }

            public readonly string OutputPath;
            public readonly string CodeAnalysisRuleset;
            public readonly bool IsCodeAnalysisEnabled;
            public readonly bool TreatWarningsAsErrors;
            public readonly bool IsCodeContractsEnabled;
            public readonly int WarningLevel;
        }

        /// <summary>Encapsulates information about a referenced assembly.</summary>

        public sealed class AssemblyReference
        {
            public AssemblyReference(XElement reference)
            {
                Include = reference.Attribute("Include").Value.Split(',')[0]; // Get rid of stuff after the first ","

                var hintElem = reference.Element(_ns + "HintPath");

                if (hintElem != null)
                    HintPath = hintElem.Value;
                else
                    HintPath = "";
            }

            public readonly string HintPath;
            public readonly string Include;
        }

        /// <summary>Constructor.</summary>

        public CSProj(string csprojFilePath)
        {
            if (!isValidProjFilePath(csprojFilePath))
                throw new ArgumentOutOfRangeException("csprojFilePath", csprojFilePath, "File does not exist, or filename does not end with '.csproj'.");

            // ReSharper disable PossibleMultipleEnumeration

            XDocument doc = XDocument.Load(csprojFilePath);

            var propertyGroups = getPropertyGroups(doc);

            //_projectFilePath = csprojFilePath;
            //_outputType = getOutputType(propertyGroups);
            //_assemblyName = getAssemblyName(propertyGroups);
            //_targetFrameworkVersion = getTargetFrameworkVersion(propertyGroups);
            //_projectDependencies = getProjectDependencies(doc);
            //_targetFrameworkProfile = getTargetFrameworkProfile(doc);
            //_xmlDocumentationFiles = getXmlDocumentationFiles(doc);
            _buildConfigurations = getBuildConfigurations(doc);
            if (_buildConfigurations.Count() > 0)
                _outputPath = _buildConfigurations[0].OutputPath;
            else
                _outputPath = "";
            //_assemblyReferences = getAssemblyReferences(doc);
            //_anyStaticCodeAnalysisEnabled = getAnyStaticCodeAnalysisEnabled(doc);
            //_platformTargets = getPlatformTargets(doc);

            // ReSharper restore PossibleMultipleEnumeration
        }

        #region Properties

        /// <summary>The project output type, e.g. "WinExe" or "Library".</summary>
        public string OutputPath { get { return _outputPath; } }
        public string OutputType { get { return _outputType; } }

        /// <summary>The project's output assembly name.</summary>

        public string AssemblyName { get { return _assemblyName; } }

        /// <summary>The target framework version, or 0.0 if not set.</summary>

        public double TargetFrameworkVersion { get { return _targetFrameworkVersion; } }

        /// <summary>The project dependencies - not to be confused with assembly references!</summary>

        public IEnumerable<string> ProjectDependencies { get { return _projectDependencies; } }

        public IEnumerable<string> XmlDocumentationFiles { get { return _xmlDocumentationFiles; } }

        public IEnumerable<BuildConfiguration> BuildConfigurations { get { return _buildConfigurations; } }

        public string TargetFrameworkProfile { get { return _targetFrameworkProfile; } }

        public IEnumerable<AssemblyReference> AssemblyReferences { get { return _assemblyReferences; } }

        public bool AnyStaticCodeAnalysisEnabled { get { return _anyStaticCodeAnalysisEnabled; } }

        public string ProjectFilePath { get { return _projectFilePath; } }

        public string[] PlatformTargets { get { return _platformTargets; } }

        #endregion Properties

        //—————————————————————————————————————————————————————————————————————————————————————————————————————————————————————

        static string[] getPlatformTargets(XDocument doc)
        {
            var result = (from item in doc.Descendants(_ns + "PlatformTarget") select item.Value).ToArray();

            if (result.Length > 0)
                return result;
            else
                return new[] { "AnyCPU" }; // If "PlatformTarget" is not specified, it defaults to "AnyCPU".
        }

        static IEnumerable<XElement> getPropertyGroups(XDocument doc)
        {
            // ReSharper disable PossibleNullReferenceException
            return doc.Element(_ns + "Project").Elements(_ns + "PropertyGroup");
            // ReSharper restore PossibleNullReferenceException
        }

        static string getOutputType(IEnumerable<XElement> propertyGroups)
        {
            return propertyGroups.Elements(_ns + "OutputType").First().Value;
        }

        static string getAssemblyName(IEnumerable<XElement> propertyGroups)
        {
            return propertyGroups.Elements(_ns + "AssemblyName").First().Value;
        }

        static double getTargetFrameworkVersion(IEnumerable<XElement> propertyGroups)
        {
            var targetFrameworkVersion = propertyGroups.Elements(_ns + "TargetFrameworkVersion").FirstOrDefault();

            if (targetFrameworkVersion != null)
                return double.Parse(targetFrameworkVersion.Value.Substring(1)); // Skip first character, which is "v"; eg like "v3.5"
            else
                return 0;
        }

        static string[] getProjectDependencies(XDocument doc)
        {
            return
            (
                from item in doc.Descendants(_ns + "ProjectReference")
                select item.Attribute("Include").Value
            )
            .ToArray();
        }

        static string getTargetFrameworkProfile(XDocument doc)
        {
            var targetFrameworkProfile = doc.Descendants(_ns + "TargetFrameworkProfile").FirstOrDefault();

            if (targetFrameworkProfile != null)
                return targetFrameworkProfile.Value;
            else
                return "";
        }

        static string[] getXmlDocumentationFiles(XDocument doc)
        {
            return
            (
                from item in doc.Descendants(_ns + "DocumentationFile")
                select item.Value
            )
            .ToArray();
        }

        static BuildConfiguration[] getBuildConfigurations(XDocument doc)
        {
            var configGroups = from item in doc.Descendants(_ns + "PropertyGroup")
                               where item.Descendants(_ns + "OutputPath").Any()
                               select new BuildConfiguration(item);

            return configGroups.ToArray();
        }

        static AssemblyReference[] getAssemblyReferences(XDocument doc)
        {
            var references = from item in doc.Descendants(_ns + "Reference")
                             select new AssemblyReference(item);

            return references.ToArray();
        }

        static bool getAnyStaticCodeAnalysisEnabled(XDocument doc)
        {
            return doc.Descendants(_ns + "CodeContractsRunCodeAnalysis")
                .Where(item => item.Attribute("Condition") == null) // Some of these have a "Condition" attribute, which is OK.
                .Any(item => string.Compare(item.Value, "true", StringComparison.OrdinalIgnoreCase) == 0);
        }

        static bool isValidProjFilePath(string projFilePath)
        {
            return
            (
                !string.IsNullOrWhiteSpace(projFilePath)
                && (projFilePath.EndsWith(".csproj", StringComparison.OrdinalIgnoreCase) || projFilePath.EndsWith(".vbproj", StringComparison.OrdinalIgnoreCase))
                && File.Exists(projFilePath)
            );
        }

        static readonly XNamespace _ns = "http://schemas.microsoft.com/developer/msbuild/2003";

        readonly bool _anyStaticCodeAnalysisEnabled;
        readonly string _outputPath;
        readonly string _projectFilePath;
        readonly string _outputType;
        readonly string _assemblyName;
        readonly string _targetFrameworkProfile;
        readonly double _targetFrameworkVersion;

        readonly string[] _projectDependencies;
        readonly string[] _xmlDocumentationFiles;
        readonly string[] _platformTargets;

        readonly BuildConfiguration[] _buildConfigurations;
        readonly AssemblyReference[] _assemblyReferences;
    }
}