// Copyright (c) Microsoft Corporation. All rights reserved.

// Licensed under the MIT License.

using System;

using System.Collections.Generic;

#if !CORECLR

using System.ComponentModel.Composition;

#endif

using System.Globalization;

using System.Linq;

using System.Management.Automation;

using System.Management.Automation.Language;

using Microsoft.Windows.PowerShell.ScriptAnalyzer.Generic;

namespace Microsoft.Windows.PowerShell.ScriptAnalyzer.BuiltinRules

{

/// <summary>

/// AvoidExclaimOperator: Checks for use of the exclaim operator

/// </summary>

#if !CORECLR

[Export(typeof(IScriptRule))]

#endif

public class AvoidExclaimOperator : ConfigurableRule

{

/// <summary>

/// Construct an object of AvoidExclaimOperator type.

/// </summary>

public AvoidExclaimOperator() {

Enable = false;

}

/// <summary>

/// Analyzes the given ast to find the [violation]

/// </summary>

/// <param name="ast">AST to be analyzed. This should be non-null</param>

/// <param name="fileName">Name of file that corresponds to the input AST.</param>

/// <returns>A an enumerable type containing the violations</returns>

public override IEnumerable<DiagnosticRecord> AnalyzeScript(Ast ast, string fileName)

{

if (ast == null) throw new ArgumentNullException(Strings.NullAstErrorMessage);

var diagnosticRecords = new List<DiagnosticRecord>();

IEnumerable<Ast> foundAsts = ast.FindAll(testAst => testAst is UnaryExpressionAst, true);

if (foundAsts != null) {

var correctionDescription = Strings.AvoidExclaimOperatorCorrectionDescription;

foreach (UnaryExpressionAst unaryExpressionAst in foundAsts) {

if (unaryExpressionAst.TokenKind == TokenKind.Exclaim) {

var replaceWith = "-not";

// The UnaryExpressionAST should have a single child, the argument that the unary operator is acting upon.

// If the child's extent starts 1 after the parent's extent then there's no whitespace between the exclaim

// token and any variable/expression; in that case the replacement -not should include a space

if (unaryExpressionAst.Child != null && unaryExpressionAst.Child.Extent.StartColumnNumber == unaryExpressionAst.Extent.StartColumnNumber + 1) {

replaceWith = "-not ";

}

var corrections = new List<CorrectionExtent> {

new CorrectionExtent(

unaryExpressionAst.Extent.StartLineNumber,

unaryExpressionAst.Extent.EndLineNumber,

unaryExpressionAst.Extent.StartColumnNumber,

unaryExpressionAst.Extent.StartColumnNumber + 1,

replaceWith,

fileName,

correctionDescription

)

};

diagnosticRecords.Add(new DiagnosticRecord(

string.Format(

CultureInfo.CurrentCulture,

Strings.AvoidExclaimOperatorError

),

unaryExpressionAst.Extent,

GetName(),

GetDiagnosticSeverity(),

fileName,

suggestedCorrections: corrections

));

}

}

}

return diagnosticRecords;

}

/// <summary>

/// Retrieves the common name of this rule.

/// </summary>

public override string GetCommonName()

{

return string.Format(CultureInfo.CurrentCulture, Strings.AvoidExclaimOperatorCommonName);

}

/// <summary>

/// Retrieves the description of this rule.

/// </summary>

public override string GetDescription()

{

return string.Format(CultureInfo.CurrentCulture, Strings.AvoidExclaimOperatorDescription);

}

/// <summary>

/// Retrieves the name of this rule.

/// </summary>

public override string GetName()

{

return string.Format(

CultureInfo.CurrentCulture,

Strings.NameSpaceFormat,

GetSourceName(),

Strings.AvoidExclaimOperatorName);

}

/// <summary>

/// Retrieves the severity of the rule: error, warning or information.

/// </summary>

public override RuleSeverity GetSeverity()

{

return RuleSeverity.Warning;

}

/// <summary>

/// Gets the severity of the returned diagnostic record: error, warning, or information.

/// </summary>

/// <returns></returns>

public DiagnosticSeverity GetDiagnosticSeverity()

{

return DiagnosticSeverity.Warning;

}

/// <summary>

/// Retrieves the name of the module/assembly the rule is from.

/// </summary>

public override string GetSourceName()

{

return string.Format(CultureInfo.CurrentCulture, Strings.SourceName);

}

/// <summary>

/// Retrieves the type of the rule, Builtin, Managed or Module.

/// </summary>

public override SourceType GetSourceType()

{

return SourceType.Builtin;

}

}

}