package generate

import (
	"bytes"
	"code.squareroundforest.org/arpio/notation"
	"fmt"
	"os"
	"path"
	"runtime"
	"strings"
	"testing"
)

func check(c ...string) map[string]string {
	m := make(map[string]string)
	for i := 0; i < len(c); i += 2 {
		name := c[i]

		var value string
		if i < len(c)-1 {
			value = c[i+1]
		}

		m[name] = value
	}

	return m
}

func testGenerate(check map[string]string, errstr string, o options, gopath ...string) func(t *testing.T) {
	return func(t *testing.T) {
		d, err := generate(o, gopath...)
		if errstr != "" {
			if err == nil {
				t.Fatal("failed to fail")
			}

			if !strings.Contains(err.Error(), errstr) {
				t.Fatal("unexpected error", err)
			}

			return
		}

		if err != nil {
			t.Fatal(err)
		}

		var failed bool
		for name, expect := range check {
			dn, ok := d[name]
			if !ok {
				failed = true
				break
			}

			if !strings.Contains(dn, expect) {
				failed = true
				break
			}
		}

		if failed {
			t.Log("failed to get the right documentation")
			t.Log("expected matches:")
			t.Log(notation.Sprintw(check))
			t.Log("documetation got:")
			t.Log(notation.Sprintw(d))
			t.Fatal()
		}
	}
}

func TestGenerate(t *testing.T) {
	wd := path.Clean(path.Join(os.Getenv("PWD"), ".."))
	h := os.Getenv("HOME")
	o := options{
		wd:     wd,
		goroot: runtime.GOROOT(),
		gomod:  "code.squareroundforest.org/arpio/docreflect",
		modules: map[string]string{
			"golang.org/x/mod@v0.27.0": path.Join(h, "go", "pkg/mod", "golang.org/x/mod@v0.27.0"),
			"code.squareroundforest.org/arpio/notation@v0.0.0-20241225183158-af3bd591a174": path.Join(
				h, "go", "pkg/mod", "code.squareroundforest.org/arpio/notation@v0.0.0-20241225183158-af3bd591a174",
			),
			"code.squareroundforest.org/arpio/docreflect": wd,
		},
	}

	t.Run("generate", func(t *testing.T) {
		t.Run(
			"stdlib",
			testGenerate(check("strings.Join", "Join concatenates", "strings.Join", "func(elems, sep)"), "", o, "strings.Join"),
		)

		notationPrintln := "code.squareroundforest.org/arpio/notation.Println"
		t.Run(
			"imported module",
			testGenerate(
				check(
					notationPrintln,
					"Println prints",
					notationPrintln,
					"func(v)",
				),
				"",
				o,
				notationPrintln,
			),
		)

		localDocs := "code.squareroundforest.org/arpio/docreflect.Docs"
		t.Run(
			"local",
			testGenerate(check(localDocs, "Docs returns the documentation for"), "", o, localDocs),
		)

		packagePath := "code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage"
		t.Run(
			"package",
			testGenerate(
				check(
					packagePath, "Package testpackage is a test package",
					fmt.Sprintf("%s.ExportedType", packagePath), "ExportedType has docs",
					fmt.Sprintf("%s.ExportedType.Bar.Baz", packagePath), "Baz is another field",
				),
				"",
				o,
				packagePath,
			),
		)

		t.Run("symbol", func(t *testing.T) {
			t.Run("type", testGenerate(
				check(
					"code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.ExportedType",
					"ExportedType has docs",
					"code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.ExportedType2",
					"",
				),
				"",
				o,
				"code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.ExportedType",
				"code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.ExportedType2",
			))

			t.Run("const", testGenerate(
				check(
					"code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.C1",
					"C1 is a const",
				),
				"",
				o,
				"code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.C1",
			))

			t.Run("const grouped", testGenerate(
				check(
					"code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.C3",
					"Cx is a const",
				),
				"",
				o,
				"code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.C3",
			))

			t.Run("var", testGenerate(
				check(
					"code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.V1",
					"V1 is a var",
				),
				"",
				o,
				"code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.V1",
			))

			t.Run("var grouped", testGenerate(
				check(
					"code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.V3",
					"Vx is a var",
				),
				"",
				o,
				"code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.V3",
			))

			t.Run("func", testGenerate(
				check(
					"code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.ExportedFunc",
					"ExportedFunc has documentation",
					"code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.New",
					"New create a new instance of ExportedType",
				),
				"",
				o,
				"code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.New",
				"code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.ExportedFunc",
			))
		})

		t.Run("field", testGenerate(
			check(
				"code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.ExportedType.Foo",
				"Foo is a field",
			),
			"",
			o,
			"code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.ExportedType.Foo",
		))

		t.Run("method", testGenerate(
			check(
				"code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.ExportedType.Method",
				"Method is a method of ExportedType",
			),
			"",
			o,
			"code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.ExportedType.Method",
		))

		t.Run("inline struct type expression", testGenerate(
			check(
				"code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.ExportedType.Bar",
				"Bar is an inline struct type expression",
				"code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.ExportedType.Bar.Baz",
				"Baz is another field",
			),
			"",
			o,
			"code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.ExportedType.Bar",
			"code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.ExportedType.Bar.Baz",
		))

		t.Run("unexported symbol", testGenerate(
			check(
				"code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.unexportedFunc",
				"unexportedFunc can have documentation",
			),
			"",
			o,
			"code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.unexportedFunc",
		))

		mainFunc := "code.squareroundforest.org/arpio/docreflect/internal/tests/src/command.main"
		t.Run("main package", testGenerate(check(mainFunc, "main func"), "", o, mainFunc))

		anum := fmt.Sprintf("%s.A", packagePath)
		bnum := fmt.Sprintf("%s.B", packagePath)
		cnum := fmt.Sprintf("%s.C", packagePath)
		t.Run(
			"grouped types",
			testGenerate(
				check(anum, "A is a number", bnum, "B is another number", cnum, "C is a third number"),
				"",
				o,
				packagePath,
			),
		)

		t.Run(
			"grouped types as symbol",
			testGenerate(check(anum, "A is a number"), "", o, anum),
		)

		pfoo := fmt.Sprintf("%s.ExportedType.PFoo", packagePath)
		barPBaz := fmt.Sprintf("%s.ExportedType.Bar.PBaz", packagePath)
		t.Run(
			"pointer field",
			testGenerate(
				check(pfoo, "PFoo is a pointer field", barPBaz, "PBaz is another pointer field"),
				"",
				o,
				packagePath,
			),
		)

		t.Run(
			"pointer field as symbol",
			testGenerate(
				check(pfoo, "PFoo is a pointer field", barPBaz, "PBaz is another pointer field"),
				"",
				o,
				pfoo,
				barPBaz,
			),
		)

		quxQuux := fmt.Sprintf("%s.ExportedType.Qux.Quux", packagePath)
		t.Run(
			"anonymous pointer struct field",
			testGenerate(
				check(quxQuux, "Quux is a number"),
				"",
				o,
				packagePath,
			),
		)

		t.Run(
			"anonymous pointer struct field as symbol",
			testGenerate(
				check(quxQuux, "Quux is a number"),
				"",
				o,
				quxQuux,
			),
		)
	})

	t.Run("errors", func(t *testing.T) {
		t.Run("package not found", testGenerate(nil, "package", o, "foo.bar.baz/qux"))
		t.Run(
			"symbol not found",
			testGenerate(nil, "symbol", o, "code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.Qux"),
		)

		t.Run(
			"field not found",
			testGenerate(
				nil,
				"symbol",
				o,
				"code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.ExportedType.Corge",
			),
		)

		t.Run(
			"field not found, second level",
			testGenerate(
				nil,
				"symbol",
				o,
				"code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.ExportedType.Foo.Qux",
			),
		)

		t.Run(
			"method not found",
			testGenerate(nil, "symbol", o, "code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.ExportedType2.Qux"),
		)

		t.Run(
			"invalid path",
			testGenerate(nil, "foo", o, "./foo/bar"),
		)

		t.Run(
			"non-existent module path",
			testGenerate(nil, "package", o, "code.squareroundforest.org/arpio/notation/foo.Foo"),
		)

		t.Run(
			"parse failed, syntax error",
			testGenerate(nil, "package", o, "code.squareroundforest.org/arpio/docreflect/internal/tests/src/syntaxerror"),
		)

		t.Run(
			"no type spec",
			testGenerate(nil, "symbol", o, "code.squareroundforest.org/arpio/docreflect/internal/tests/src/testpackage.Foo.Qux"),
		)
	})

	t.Run("init options", func(t *testing.T) {
		o := initOptions()
		if o.wd != os.Getenv("PWD") {
			t.Fatal("wd")
		}

		if o.goroot != runtime.GOROOT() {
			t.Fatal("goroot")
		}

		if o.gomod != "code.squareroundforest.org/arpio/docreflect" {
			t.Fatal("gomod")
		}

		for _, module := range []string{
			"code.squareroundforest.org/arpio/notation",
			"golang.org/x/mod",
		} {
			var found bool
			for key := range o.modules {
				if strings.Contains(key, module) {
					found = true
				}
			}

			if !found {
				t.Fatal("gomod")
			}
		}
	})
}

func TestFormat(t *testing.T) {
	b := bytes.NewBuffer(nil)
	d := map[string]string{
		"foo": "bar",
		"baz": "qux",
	}

	if err := format(b, "testpackage", d); err != nil {
		t.Fatal(err)
	}

	o := b.String()
	if o != `package testpackage
import "code.squareroundforest.org/arpio/docreflect"
func init() {
docreflect.Register("baz", "qux")
docreflect.Register("foo", "bar")
}` {
		t.Fatal()
	}
}