package parser_test

import (
	"io/fs"
	"iter"
	"os"
	"path/filepath"
	"strings"
	"testing"

	"github.com/microsoft/typescript-go/internal/ast"
	"github.com/microsoft/typescript-go/internal/collections"
	"github.com/microsoft/typescript-go/internal/core"
	"github.com/microsoft/typescript-go/internal/parser"
	"github.com/microsoft/typescript-go/internal/repo"
	"github.com/microsoft/typescript-go/internal/testrunner"
	"github.com/microsoft/typescript-go/internal/testutil/fixtures"
	"github.com/microsoft/typescript-go/internal/tspath"
	"github.com/microsoft/typescript-go/internal/vfs/osvfs"
	"gotest.tools/v3/assert"
)

func BenchmarkParse(b *testing.B) {
	for _, f := range fixtures.BenchFixtures {
		b.Run(f.Name(), func(b *testing.B) {
			f.SkipIfNotExist(b)

			fileName := tspath.GetNormalizedAbsolutePath(f.Path(), "/")
			path := tspath.ToPath(fileName, "/", osvfs.FS().UseCaseSensitiveFileNames())
			sourceText := f.ReadFile(b)
			scriptKind := core.GetScriptKindFromFileName(fileName)

			opts := ast.SourceFileParseOptions{
				FileName: fileName,
				Path:     path,
			}

			for b.Loop() {
				parser.ParseSourceFile(opts, sourceText, scriptKind)
			}
		})
	}
}

type parsableFile struct {
	path string
	name string
}

func allParsableFiles(tb testing.TB, root string) iter.Seq[parsableFile] {
	tb.Helper()
	return func(yield func(parsableFile) bool) {
		tb.Helper()
		err := filepath.WalkDir(root, func(path string, d fs.DirEntry, err error) error {
			if err != nil {
				return err
			}

			if d.IsDir() || tspath.TryGetExtensionFromPath(path) == "" {
				return nil
			}

			testName, err := filepath.Rel(root, path)
			if err != nil {
				return err
			}
			testName = filepath.ToSlash(testName)

			if !yield(parsableFile{path, testName}) {
				return filepath.SkipAll
			}
			return nil
		})
		assert.NilError(tb, err)
	}
}

func FuzzParser(f *testing.F) {
	repo.SkipIfNoTypeScriptSubmodule(f)

	tests := []string{
		"src",
		"scripts",
		"Herebyfile.mjs",
	}

	var extensions collections.Set[string]
	for _, es := range tspath.AllSupportedExtensionsWithJson {
		for _, e := range es {
			extensions.Add(e)
		}
	}

	for _, test := range tests {
		root := filepath.Join(repo.TypeScriptSubmodulePath(), test)

		for file := range allParsableFiles(f, root) {
			sourceText, err := os.ReadFile(file.path)
			assert.NilError(f, err)
			extension := tspath.TryGetExtensionFromPath(file.path)
			f.Add(extension, string(sourceText), false, false)
		}
	}

	testDirs := []string{
		filepath.Join(repo.TypeScriptSubmodulePath(), "tests/cases/compiler"),
		filepath.Join(repo.TypeScriptSubmodulePath(), "tests/cases/conformance"),
		filepath.Join(repo.TestDataPath(), "tests/cases/compiler"),
	}

	for _, testDir := range testDirs {
		if _, err := os.Stat(testDir); os.IsNotExist(err) {
			continue
		}

		for file := range allParsableFiles(f, testDir) {
			sourceText, err := os.ReadFile(file.path)
			assert.NilError(f, err)

			type testFile struct {
				content string
				name    string
			}

			testUnits, _, _, _, err := testrunner.ParseTestFilesAndSymlinks(
				string(sourceText),
				file.path,
				func(filename string, content string, fileOptions map[string]string) (testFile, error) {
					return testFile{content: content, name: filename}, nil
				},
			)
			assert.NilError(f, err)

			for _, unit := range testUnits {
				extension := tspath.TryGetExtensionFromPath(unit.name)
				if extension == "" {
					continue
				}
				f.Add(extension, unit.content, false, false)
			}
		}
	}

	f.Fuzz(func(t *testing.T, extension string, sourceText string, externalModuleIndicatorOptionsJSX bool, externalModuleIndicatorOptionsForce bool) {
		if !extensions.Has(extension) {
			t.Skip()
		}

		fileName := "/index" + extension
		path := tspath.Path(fileName)

		opts := ast.SourceFileParseOptions{
			FileName: fileName,
			Path:     path,
			ExternalModuleIndicatorOptions: ast.ExternalModuleIndicatorOptions{
				JSX:   externalModuleIndicatorOptionsJSX,
				Force: externalModuleIndicatorOptionsForce,
			},
		}

		parser.ParseSourceFile(opts, sourceText, core.GetScriptKindFromFileName(fileName))
	})
}

func TestJSDocImportTypeParentChain(t *testing.T) {
	t.Parallel()
	sourceText := `test("", async function () {
  ;(/** @type {typeof import("a")} */ ({}))
})

test("", async function () {
  ;(/** @type {typeof import("a")} */ a)
})

test("", async function () {
  (/** @type {typeof import("a")} */ ({}))
  ;(/** @type {typeof import("a")} */ ({}))
})

test("", async function () {
  (/** @type {typeof import("a")} */ a)
  ;(/** @type {typeof import("a")} */ a)
})

test("", async function () {
  (/** @type {typeof import("a")} */ ({}))
  ;(/** @type {typeof import("a")} */ ({}))
})
`
	opts := ast.SourceFileParseOptions{
		FileName: "/index.js",
		Path:     "/index.js",
	}

	file := parser.ParseSourceFile(opts, sourceText, core.ScriptKindJS)

	for i := 1; i < len(file.ReparsedClones); i++ {
		a, b := file.ReparsedClones[i-1], file.ReparsedClones[i]
		if a.Pos() == b.Pos() && a.End() == b.End() && a.Kind == b.Kind {
			t.Errorf("duplicate ReparsedClones at [%d] and [%d]: %s pos=%d end=%d", i-1, i, a.Kind.String(), a.Pos(), a.End())
		}
	}

	for _, imp := range file.Imports() {
		reparsed := ast.GetReparsedNodeForNode(imp)
		if ast.GetSourceFileOfNode(reparsed) == nil {
			t.Errorf("reparsed import at pos=%d has broken parent chain", imp.Pos())
		}
	}
}

func TestSourceFileContainsNonASCIIInStringLiteralFastPath(t *testing.T) {
	t.Parallel()
	sourceText := `const x = "─";

namespace N {
  export const y = x;
}
`
	opts := ast.SourceFileParseOptions{
		FileName: "/index.ts",
		Path:     "/index.ts",
	}

	file := parser.ParseSourceFile(opts, sourceText, core.ScriptKindTS)

	assert.Assert(t, file.ContainsNonASCII)
	positionMap := file.GetPositionMap()
	assert.Assert(t, !positionMap.IsAsciiOnly())
	afterBoxDrawingCharacter := strings.Index(sourceText, "─") + len("─")
	assert.Equal(t, positionMap.UTF8ToUTF16(afterBoxDrawingCharacter), afterBoxDrawingCharacter-2)
	assert.Equal(t, positionMap.UTF8ToUTF16(len(sourceText)), len(sourceText)-2)
}