/*
 * Copyright (c) 2024 The GoPlus Authors (goplus.org). All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package cl

import (
	"go/ast"
	"go/parser"
	"go/token"
	"go/types"
	"log"
	"os"
	"path"
	"strings"
	"testing"

	"github.com/goplus/gogen/packages"
	"golang.org/x/tools/go/ssa"
	"golang.org/x/tools/go/ssa/ssautil"

	llssa "github.com/goplus/llgo/ssa"
)

func TestFromTestdata(t *testing.T) {
	testFromDir(t, "", "./_testdata")
}

func init() {
	SetDebug(DbgFlagAll)
	llssa.Initialize(llssa.InitAll)
	llssa.SetDebug(llssa.DbgFlagAll)
}

func testFromDir(t *testing.T, sel, relDir string) {
	dir, err := os.Getwd()
	if err != nil {
		t.Fatal("Getwd failed:", err)
	}
	dir = path.Join(dir, relDir)
	fis, err := os.ReadDir(dir)
	if err != nil {
		t.Fatal("ReadDir failed:", err)
	}
	for _, fi := range fis {
		name := fi.Name()
		if !fi.IsDir() || strings.HasPrefix(name, "_") {
			continue
		}
		t.Run(name, func(t *testing.T) {
			testFrom(t, dir+"/"+name, sel)
		})
	}
}

func testFrom(t *testing.T, pkgDir, sel string) {
	if sel != "" && !strings.Contains(pkgDir, sel) {
		return
	}
	log.Println("Parsing", pkgDir)
	in := pkgDir + "/in.go"
	out := pkgDir + "/out.ll"
	expected, err := os.ReadFile(out)
	if err != nil {
		t.Fatal("ReadFile failed:", err)
	}
	testCompileEx(t, nil, in, string(expected))
}

func testCompileEx(t *testing.T, src any, fname, expected string) {
	t.Helper()
	fset := token.NewFileSet()
	f, err := parser.ParseFile(fset, fname, src, parser.ParseComments)
	if err != nil {
		t.Fatal("ParseFile failed:", err)
	}
	files := []*ast.File{f}
	name := f.Name.Name
	pkg := types.NewPackage(name, name)
	imp := packages.NewImporter(fset)
	foo, _, err := ssautil.BuildPackage(
		&types.Config{Importer: imp}, fset, pkg, files, ssa.SanityCheckFunctions)
	if err != nil {
		t.Fatal("BuildPackage failed:", err)
	}
	foo.WriteTo(os.Stderr)
	prog := llssa.NewProgram(nil)
	ret, err := NewPackage(prog, foo, files)
	if err != nil {
		t.Fatal("cl.NewPackage failed:", err)
	}
	if v := ret.String(); v != expected {
		t.Fatalf("\n==> got:\n%s\n==> expected:\n%s\n", v, expected)
	}
}

func testCompile(t *testing.T, src, expected string) {
	t.Helper()
	testCompileEx(t, src, "foo.go", expected)
}

func TestVar(t *testing.T) {
	testCompile(t, `package foo

var a int
`, `; ModuleID = 'foo'
source_filename = "foo"

@"foo.init$guard" = global ptr null
@foo.a = global ptr null

define void @foo.init() {
_llgo_0:
  %0 = load i1, ptr @"foo.init$guard", align 1
  br i1 %0, label %_llgo_2, label %_llgo_1

_llgo_1:                                          ; preds = %_llgo_0
  store i1 true, ptr @"foo.init$guard", align 1
  br label %_llgo_2

_llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
  ret void
}
`)
}

func TestBasicFunc(t *testing.T) {
	testCompile(t, `package foo

func fn(a int, b float64) int {
	return 1
}
`, `; ModuleID = 'foo'
source_filename = "foo"

@"foo.init$guard" = global ptr null

define void @foo.init() {
_llgo_0:
  %0 = load i1, ptr @"foo.init$guard", align 1
  br i1 %0, label %_llgo_2, label %_llgo_1

_llgo_1:                                          ; preds = %_llgo_0
  store i1 true, ptr @"foo.init$guard", align 1
  br label %_llgo_2

_llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
  ret void
}

define i64 @foo.fn(i64 %0, double %1) {
_llgo_0:
  ret i64 1
}
`)
}