package gosec_test

import (
	"errors"
	"io/ioutil"
	"log"
	"os"
	"strings"

	"github.com/securego/gosec"
	"github.com/securego/gosec/rules"
	"golang.org/x/tools/go/packages"

	. "github.com/onsi/ginkgo"
	. "github.com/onsi/gomega"
	"github.com/securego/gosec/testutils"
)

var _ = Describe("Analyzer", func() {

	var (
		analyzer  *gosec.Analyzer
		logger    *log.Logger
		buildTags []string
		tests     bool
	)
	BeforeEach(func() {
		logger, _ = testutils.NewLogger()
		analyzer = gosec.NewAnalyzer(nil, tests, logger)
	})

	Context("when processing a package", func() {

		It("should not report an error if the package contains no Go files", func() {
			analyzer.LoadRules(rules.Generate().Builders())
			dir, err := ioutil.TempDir("", "empty")
			defer os.RemoveAll(dir)
			Expect(err).ShouldNot(HaveOccurred())
			err = analyzer.Process(buildTags, dir)
			Expect(err).ShouldNot(HaveOccurred())
			_, _, errors := analyzer.Report()
			Expect(len(errors)).To(Equal(0))
		})

		It("should report an error if the package fails to build", func() {
			analyzer.LoadRules(rules.Generate().Builders())
			pkg := testutils.NewTestPackage()
			defer pkg.Close()
			pkg.AddFile("wonky.go", `func main(){ println("forgot the package")}`)
			err := pkg.Build()
			Expect(err).Should(HaveOccurred())
			err = analyzer.Process(buildTags, pkg.Path)
			Expect(err).ShouldNot(HaveOccurred())
			_, _, errors := analyzer.Report()
			Expect(len(errors)).To(Equal(1))
			for _, ferr := range errors {
				Expect(len(ferr)).To(Equal(1))
			}
		})

		It("should be able to analyze multiple Go files", func() {
			analyzer.LoadRules(rules.Generate().Builders())
			pkg := testutils.NewTestPackage()
			defer pkg.Close()
			pkg.AddFile("foo.go", `
				package main
				func main(){
					bar()
				}`)
			pkg.AddFile("bar.go", `
				package main
				func bar(){
					println("package has two files!")
				}`)
			err := pkg.Build()
			Expect(err).ShouldNot(HaveOccurred())
			err = analyzer.Process(buildTags, pkg.Path)
			Expect(err).ShouldNot(HaveOccurred())
			_, metrics, _ := analyzer.Report()
			Expect(metrics.NumFiles).To(Equal(2))
		})

		It("should be able to analyze multiple Go packages", func() {
			analyzer.LoadRules(rules.Generate().Builders())
			pkg1 := testutils.NewTestPackage()
			pkg2 := testutils.NewTestPackage()
			defer pkg1.Close()
			defer pkg2.Close()
			pkg1.AddFile("foo.go", `
				package main
				func main(){
				}`)
			pkg2.AddFile("bar.go", `
				package main
				func bar(){
				}`)
			err := pkg1.Build()
			Expect(err).ShouldNot(HaveOccurred())
			err = pkg2.Build()
			Expect(err).ShouldNot(HaveOccurred())
			err = analyzer.Process(buildTags, pkg1.Path, pkg2.Path)
			Expect(err).ShouldNot(HaveOccurred())
			_, metrics, _ := analyzer.Report()
			Expect(metrics.NumFiles).To(Equal(2))
		})

		It("should find errors when nosec is not in use", func() {
			sample := testutils.SampleCodeG401[0]
			source := sample.Code[0]
			analyzer.LoadRules(rules.Generate(rules.NewRuleFilter(false, "G401")).Builders())

			controlPackage := testutils.NewTestPackage()
			defer controlPackage.Close()
			controlPackage.AddFile("md5.go", source)
			err := controlPackage.Build()
			Expect(err).ShouldNot(HaveOccurred())
			err = analyzer.Process(buildTags, controlPackage.Path)
			Expect(err).ShouldNot(HaveOccurred())
			controlIssues, _, _ := analyzer.Report()
			Expect(controlIssues).Should(HaveLen(sample.Errors))

		})

		It("should report Go build errors and invalid files", func() {
			analyzer.LoadRules(rules.Generate().Builders())
			pkg := testutils.NewTestPackage()
			defer pkg.Close()
			pkg.AddFile("foo.go", `
				package main
				func main()
				}`)
			err := pkg.Build()
			Expect(err).ShouldNot(HaveOccurred())
			err = analyzer.Process(buildTags, pkg.Path)
			Expect(err).ShouldNot(HaveOccurred())
			_, _, errors := analyzer.Report()
			Expect(len(errors)).To(Equal(1))
			for _, ferr := range errors {
				Expect(len(ferr)).To(Equal(1))
				Expect(ferr[0].Line).To(Equal(4))
				Expect(ferr[0].Column).To(Equal(5))
				Expect(ferr[0].Err).Should(MatchRegexp(`expected declaration, found '}'`))
			}
		})

		It("should not report errors when a nosec comment is present", func() {
			sample := testutils.SampleCodeG401[0]
			source := sample.Code[0]
			analyzer.LoadRules(rules.Generate(rules.NewRuleFilter(false, "G401")).Builders())

			nosecPackage := testutils.NewTestPackage()
			defer nosecPackage.Close()
			nosecSource := strings.Replace(source, "h := md5.New()", "h := md5.New() // #nosec", 1)
			nosecPackage.AddFile("md5.go", nosecSource)
			err := nosecPackage.Build()
			Expect(err).ShouldNot(HaveOccurred())
			err = analyzer.Process(buildTags, nosecPackage.Path)
			Expect(err).ShouldNot(HaveOccurred())
			nosecIssues, _, _ := analyzer.Report()
			Expect(nosecIssues).Should(BeEmpty())
		})

		It("should not report errors when an exclude comment is present for the correct rule", func() {
			// Rule for MD5 weak crypto usage
			sample := testutils.SampleCodeG401[0]
			source := sample.Code[0]
			analyzer.LoadRules(rules.Generate(rules.NewRuleFilter(false, "G401")).Builders())

			nosecPackage := testutils.NewTestPackage()
			defer nosecPackage.Close()
			nosecSource := strings.Replace(source, "h := md5.New()", "h := md5.New() // #nosec G401", 1)
			nosecPackage.AddFile("md5.go", nosecSource)
			err := nosecPackage.Build()
			Expect(err).ShouldNot(HaveOccurred())
			err = analyzer.Process(buildTags, nosecPackage.Path)
			Expect(err).ShouldNot(HaveOccurred())
			nosecIssues, _, _ := analyzer.Report()
			Expect(nosecIssues).Should(BeEmpty())
		})

		It("should report errors when an exclude comment is present for a different rule", func() {
			sample := testutils.SampleCodeG401[0]
			source := sample.Code[0]
			analyzer.LoadRules(rules.Generate(rules.NewRuleFilter(false, "G401")).Builders())

			nosecPackage := testutils.NewTestPackage()
			defer nosecPackage.Close()
			nosecSource := strings.Replace(source, "h := md5.New()", "h := md5.New() // #nosec G301", 1)
			nosecPackage.AddFile("md5.go", nosecSource)
			err := nosecPackage.Build()
			Expect(err).ShouldNot(HaveOccurred())
			err = analyzer.Process(buildTags, nosecPackage.Path)
			Expect(err).ShouldNot(HaveOccurred())
			nosecIssues, _, _ := analyzer.Report()
			Expect(nosecIssues).Should(HaveLen(sample.Errors))
		})

		It("should not report errors when an exclude comment is present for multiple rules, including the correct rule", func() {
			sample := testutils.SampleCodeG401[0]
			source := sample.Code[0]
			analyzer.LoadRules(rules.Generate(rules.NewRuleFilter(false, "G401")).Builders())

			nosecPackage := testutils.NewTestPackage()
			defer nosecPackage.Close()
			nosecSource := strings.Replace(source, "h := md5.New()", "h := md5.New() // #nosec G301 G401", 1)
			nosecPackage.AddFile("md5.go", nosecSource)
			err := nosecPackage.Build()
			Expect(err).ShouldNot(HaveOccurred())
			err = analyzer.Process(buildTags, nosecPackage.Path)
			Expect(err).ShouldNot(HaveOccurred())
			err = analyzer.Process(buildTags, nosecPackage.Path)
			Expect(err).ShouldNot(HaveOccurred())
			nosecIssues, _, _ := analyzer.Report()
			Expect(nosecIssues).Should(BeEmpty())
		})

		It("should pass the build tags", func() {
			sample := testutils.SampleCode601[0]
			source := sample.Code[0]
			analyzer.LoadRules(rules.Generate().Builders())
			pkg := testutils.NewTestPackage()
			defer pkg.Close()
			pkg.AddFile("tags.go", source)
			tags := []string{"tag"}
			err := analyzer.Process(tags, pkg.Path)
			Expect(err).ShouldNot(HaveOccurred())
		})

		It("should process an empty package with test file", func() {
			analyzer.LoadRules(rules.Generate().Builders())
			pkg := testutils.NewTestPackage()
			defer pkg.Close()
			pkg.AddFile("foo_test.go", `
				package tests
			    import "testing"
			    func TestFoo(t *testing.T){
			    }`)
			err := pkg.Build()
			Expect(err).ShouldNot(HaveOccurred())
			err = analyzer.Process(buildTags, pkg.Path)
			Expect(err).ShouldNot(HaveOccurred())
		})

		It("should be possible to overwrite nosec comments, and report issues", func() {
			// Rule for MD5 weak crypto usage
			sample := testutils.SampleCodeG401[0]
			source := sample.Code[0]

			// overwrite nosec option
			nosecIgnoreConfig := gosec.NewConfig()
			nosecIgnoreConfig.SetGlobal(gosec.Nosec, "true")
			customAnalyzer := gosec.NewAnalyzer(nosecIgnoreConfig, tests, logger)
			customAnalyzer.LoadRules(rules.Generate(rules.NewRuleFilter(false, "G401")).Builders())

			nosecPackage := testutils.NewTestPackage()
			defer nosecPackage.Close()
			nosecSource := strings.Replace(source, "h := md5.New()", "h := md5.New() // #nosec", 1)
			nosecPackage.AddFile("md5.go", nosecSource)
			err := nosecPackage.Build()
			Expect(err).ShouldNot(HaveOccurred())
			err = customAnalyzer.Process(buildTags, nosecPackage.Path)
			Expect(err).ShouldNot(HaveOccurred())
			nosecIssues, _, _ := customAnalyzer.Report()
			Expect(nosecIssues).Should(HaveLen(sample.Errors))

		})

		It("should be able to analyze Go test package", func() {
			customAnalyzer := gosec.NewAnalyzer(nil, true, logger)
			customAnalyzer.LoadRules(rules.Generate().Builders())
			pkg := testutils.NewTestPackage()
			defer pkg.Close()
			pkg.AddFile("foo.go", `
				package foo
				func foo(){
				}`)
			pkg.AddFile("foo_test.go", `
				package foo_test
				import "testing"
				func test() error {
				  return nil
				}
				func TestFoo(t *testing.T){
					test()
				}`)
			err := pkg.Build()
			Expect(err).ShouldNot(HaveOccurred())
			err = customAnalyzer.Process(buildTags, pkg.Path)
			Expect(err).ShouldNot(HaveOccurred())
			issues, _, _ := customAnalyzer.Report()
			Expect(issues).Should(HaveLen(1))
		})
	})

	Context("when parsing errors from a package", func() {

		It("should return no error when the error list is empty", func() {
			pkg := &packages.Package{}
			err := analyzer.ParseErrors(pkg)
			Expect(err).ShouldNot(HaveOccurred())
		})

		It("should properly parse the errors", func() {
			pkg := &packages.Package{
				Errors: []packages.Error{
					packages.Error{
						Pos: "file:1:2",
						Msg: "build error",
					},
				},
			}
			err := analyzer.ParseErrors(pkg)
			Expect(err).ShouldNot(HaveOccurred())
			_, _, errors := analyzer.Report()
			Expect(len(errors)).To(Equal(1))
			for _, ferr := range errors {
				Expect(len(ferr)).To(Equal(1))
				Expect(ferr[0].Line).To(Equal(1))
				Expect(ferr[0].Column).To(Equal(2))
				Expect(ferr[0].Err).Should(MatchRegexp(`build error`))
			}
		})

		It("should properly parse the errors without line and column", func() {
			pkg := &packages.Package{
				Errors: []packages.Error{
					packages.Error{
						Pos: "file",
						Msg: "build error",
					},
				},
			}
			err := analyzer.ParseErrors(pkg)
			Expect(err).ShouldNot(HaveOccurred())
			_, _, errors := analyzer.Report()
			Expect(len(errors)).To(Equal(1))
			for _, ferr := range errors {
				Expect(len(ferr)).To(Equal(1))
				Expect(ferr[0].Line).To(Equal(0))
				Expect(ferr[0].Column).To(Equal(0))
				Expect(ferr[0].Err).Should(MatchRegexp(`build error`))
			}
		})

		It("should properly parse the errors without column", func() {
			pkg := &packages.Package{
				Errors: []packages.Error{
					packages.Error{
						Pos: "file",
						Msg: "build error",
					},
				},
			}
			err := analyzer.ParseErrors(pkg)
			Expect(err).ShouldNot(HaveOccurred())
			_, _, errors := analyzer.Report()
			Expect(len(errors)).To(Equal(1))
			for _, ferr := range errors {
				Expect(len(ferr)).To(Equal(1))
				Expect(ferr[0].Line).To(Equal(0))
				Expect(ferr[0].Column).To(Equal(0))
				Expect(ferr[0].Err).Should(MatchRegexp(`build error`))
			}
		})

		It("should return error when line cannot be parsed", func() {
			pkg := &packages.Package{
				Errors: []packages.Error{
					packages.Error{
						Pos: "file:line",
						Msg: "build error",
					},
				},
			}
			err := analyzer.ParseErrors(pkg)
			Expect(err).Should(HaveOccurred())
		})

		It("should return error when column cannot be parsed", func() {
			pkg := &packages.Package{
				Errors: []packages.Error{
					packages.Error{
						Pos: "file:1:column",
						Msg: "build error",
					},
				},
			}
			err := analyzer.ParseErrors(pkg)
			Expect(err).Should(HaveOccurred())
		})

		It("should append  error to the same file", func() {
			pkg := &packages.Package{
				Errors: []packages.Error{
					packages.Error{
						Pos: "file:1:2",
						Msg: "error1",
					},
					packages.Error{
						Pos: "file:3:4",
						Msg: "error2",
					},
				},
			}
			err := analyzer.ParseErrors(pkg)
			Expect(err).ShouldNot(HaveOccurred())
			_, _, errors := analyzer.Report()
			Expect(len(errors)).To(Equal(1))
			for _, ferr := range errors {
				Expect(len(ferr)).To(Equal(2))
				Expect(ferr[0].Line).To(Equal(1))
				Expect(ferr[0].Column).To(Equal(2))
				Expect(ferr[0].Err).Should(MatchRegexp(`error1`))
				Expect(ferr[1].Line).To(Equal(3))
				Expect(ferr[1].Column).To(Equal(4))
				Expect(ferr[1].Err).Should(MatchRegexp(`error2`))
			}
		})
	})

	Context("when appending errors", func() {
		It("should skip error for non-buildable packages", func() {
			analyzer.AppendError("test", errors.New(`loading file from package "pkg/test": no buildable Go source files in pkg/test`))
			_, _, errors := analyzer.Report()
			Expect(len(errors)).To(Equal(0))
		})

		It("should add a new error", func() {
			pkg := &packages.Package{
				Errors: []packages.Error{
					packages.Error{
						Pos: "file:1:2",
						Msg: "build error",
					},
				},
			}
			err := analyzer.ParseErrors(pkg)
			Expect(err).ShouldNot(HaveOccurred())
			analyzer.AppendError("file", errors.New("file build error"))
			_, _, errors := analyzer.Report()
			Expect(len(errors)).To(Equal(1))
			for _, ferr := range errors {
				Expect(len(ferr)).To(Equal(2))
			}
		})
	})
})