// Copyright 2015 syzkaller project authors. All rights reserved.
// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.

package csource

import (
	"fmt"
	"io/ioutil"
	"math/rand"
	"os"
	"os/exec"
	"path/filepath"
	"runtime"
	"strings"
	"testing"
	"time"

	"github.com/google/syzkaller/pkg/osutil"
	"github.com/google/syzkaller/prog"
	_ "github.com/google/syzkaller/sys"
	"github.com/google/syzkaller/sys/targets"
)

func TestGenerate(t *testing.T) {
	t.Parallel()
	checked := make(map[string]bool)
	for _, target := range prog.AllTargets() {
		target := target
		sysTarget := targets.Get(target.OS, target.Arch)
		if runtime.GOOS != sysTarget.BuildOS {
			continue
		}
		t.Run(target.OS+"/"+target.Arch, func(t *testing.T) {
			if target.OS == "linux" && target.Arch == "arm64" {
				// Episodically fails on travis with:
				// collect2: error: ld terminated with signal 11 [Segmentation fault]
				t.Skip("broken")
			}
			if target.OS == "test" && target.PtrSize == 4 {
				// The same reason as linux/32.
				t.Skip("broken")
			}
			if _, err := exec.LookPath(sysTarget.CCompiler); err != nil {
				t.Skipf("no target compiler %v", sysTarget.CCompiler)
			}
			full := !checked[target.OS]
			checked[target.OS] = true
			t.Parallel()
			testTarget(t, target, full)
		})

	}
}

// This is the main configuration used by executor, so we want to test it as well.
var executorOpts = Options{
	Threaded:  true,
	Collide:   true,
	Repeat:    true,
	Procs:     2,
	Sandbox:   "none",
	Repro:     true,
	UseTmpDir: true,
}

func testTarget(t *testing.T, target *prog.Target, full bool) {
	seed := time.Now().UnixNano()
	if os.Getenv("TRAVIS") != "" {
		seed = 0 // required for deterministic coverage reports
	}
	rs := rand.NewSource(seed)
	t.Logf("seed=%v", seed)
	p := target.Generate(rs, 10, nil)
	// Turns out that fully minimized program can trigger new interesting warnings,
	// e.g. about NULL arguments for functions that require non-NULL arguments in syz_ functions.
	// We could append both AllSyzProg as-is and a minimized version of it,
	// but this makes the NULL argument warnings go away (they showed up in ".constprop" versions).
	// Testing 2 programs takes too long since we have lots of options permutations and OS/arch.
	// So we use the as-is in short tests and minimized version in full tests.
	syzProg := target.GenerateAllSyzProg(rs)
	var opts []Options
	if !full || testing.Short() {
		p.Calls = append(p.Calls, syzProg.Calls...)
		opts = allOptionsSingle(target.OS)
		opts = append(opts, executorOpts)
	} else {
		minimized, _ := prog.Minimize(syzProg, -1, false, func(p *prog.Prog, call int) bool {
			return len(p.Calls) == len(syzProg.Calls)
		})
		p.Calls = append(p.Calls, minimized.Calls...)
		opts = allOptionsPermutations(target.OS)
	}
	for opti, opts := range opts {
		opts := opts
		t.Run(fmt.Sprintf("%v", opti), func(t *testing.T) {
			t.Parallel()
			testOne(t, p, opts)
		})
	}
}

func testOne(t *testing.T, p *prog.Prog, opts Options) {
	src, err := Write(p, opts)
	if err != nil {
		t.Logf("opts: %+v\nprogram:\n%s\n", opts, p.Serialize())
		t.Fatalf("%v", err)
	}
	bin, err := Build(p.Target, src)
	if err != nil {
		t.Logf("opts: %+v\nprogram:\n%s\n", opts, p.Serialize())
		t.Fatalf("%v", err)
	}
	defer os.Remove(bin)
}

func TestSysTests(t *testing.T) {
	t.Parallel()
	for _, target := range prog.AllTargets() {
		target := target
		sysTarget := targets.Get(target.OS, target.Arch)
		if runtime.GOOS != sysTarget.BuildOS {
			continue // we need at least preprocessor binary to generate sources
		}
		t.Run(target.OS+"/"+target.Arch, func(t *testing.T) {
			t.Parallel()
			dir := filepath.Join("..", "..", "sys", target.OS, "test")
			if !osutil.IsExist(dir) {
				return
			}
			files, err := ioutil.ReadDir(dir)
			if err != nil {
				t.Fatalf("failed to read %v: %v", dir, err)
			}
			for _, finfo := range files {
				file := filepath.Join(dir, finfo.Name())
				if strings.HasSuffix(file, "~") || strings.HasSuffix(file, ".swp") {
					continue
				}
				data, err := ioutil.ReadFile(file)
				if err != nil {
					t.Fatalf("failed to read %v: %v", file, err)
				}
				p, err := target.Deserialize(data, prog.Strict)
				if err != nil {
					t.Fatalf("failed to parse program %v: %v", file, err)
				}
				_, err = Write(p, executorOpts)
				if err != nil {
					t.Fatalf("failed to generate C source for %v: %v", file, err)
				}
			}
		})
	}
}