// Copyright 2014 Google Inc. 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 blueprint

import (
	"bytes"
	"errors"
	"fmt"
	"reflect"
	"strings"
	"sync"
	"testing"
	"time"

	"github.com/google/blueprint/parser"
)

type Walker interface {
	Walk() bool
}

type fooModule struct {
	SimpleName
	properties struct {
		Deps []string
		Foo  string
	}
}

func newFooModule() (Module, []interface{}) {
	m := &fooModule{}
	return m, []interface{}{&m.properties, &m.SimpleName.Properties}
}

func (f *fooModule) GenerateBuildActions(ModuleContext) {
}

func (f *fooModule) DynamicDependencies(ctx DynamicDependerModuleContext) []string {
	return f.properties.Deps
}

func (f *fooModule) Foo() string {
	return f.properties.Foo
}

func (f *fooModule) Walk() bool {
	return true
}

type barModule struct {
	SimpleName
	properties struct {
		Deps []string
		Bar  bool
	}
}

func newBarModule() (Module, []interface{}) {
	m := &barModule{}
	return m, []interface{}{&m.properties, &m.SimpleName.Properties}
}

func (b *barModule) DynamicDependencies(ctx DynamicDependerModuleContext) []string {
	return b.properties.Deps
}

func (b *barModule) GenerateBuildActions(ModuleContext) {
}

func (b *barModule) Bar() bool {
	return b.properties.Bar
}

func (b *barModule) Walk() bool {
	return false
}

func TestContextParse(t *testing.T) {
	ctx := NewContext()
	ctx.RegisterModuleType("foo_module", newFooModule)
	ctx.RegisterModuleType("bar_module", newBarModule)

	r := bytes.NewBufferString(`
		foo_module {
	        name: "MyFooModule",
			deps: ["MyBarModule"],
		}

		bar_module {
	        name: "MyBarModule",
		}
	`)

	_, _, errs := ctx.parseOne(".", "Blueprint", r, parser.NewScope(nil), nil)
	if len(errs) > 0 {
		t.Errorf("unexpected parse errors:")
		for _, err := range errs {
			t.Errorf("  %s", err)
		}
		t.FailNow()
	}

	_, errs = ctx.ResolveDependencies(nil)
	if len(errs) > 0 {
		t.Errorf("unexpected dep errors:")
		for _, err := range errs {
			t.Errorf("  %s", err)
		}
		t.FailNow()
	}
}

// |---B===D       - represents a non-walkable edge
// A               = represents a walkable edge
// |===C---E===G
//     |       |   A should not be visited because it's the root node.
//     |===F===|   B, D and E should not be walked.
func TestWalkDeps(t *testing.T) {
	ctx := NewContext()
	ctx.MockFileSystem(map[string][]byte{
		"Blueprints": []byte(`
			foo_module {
			    name: "A",
			    deps: ["B", "C"],
			}
			
			bar_module {
			    name: "B",
			    deps: ["D"],
			}
			
			foo_module {
			    name: "C",
			    deps: ["E", "F"],
			}
			
			foo_module {
			    name: "D",
			}
			
			bar_module {
			    name: "E",
			    deps: ["G"],
			}
			
			foo_module {
			    name: "F",
			    deps: ["G"],
			}
			
			foo_module {
			    name: "G",
			}
		`),
	})

	ctx.RegisterModuleType("foo_module", newFooModule)
	ctx.RegisterModuleType("bar_module", newBarModule)
	_, errs := ctx.ParseBlueprintsFiles("Blueprints")
	if len(errs) > 0 {
		t.Errorf("unexpected parse errors:")
		for _, err := range errs {
			t.Errorf("  %s", err)
		}
		t.FailNow()
	}

	_, errs = ctx.ResolveDependencies(nil)
	if len(errs) > 0 {
		t.Errorf("unexpected dep errors:")
		for _, err := range errs {
			t.Errorf("  %s", err)
		}
		t.FailNow()
	}

	var outputDown string
	var outputUp string
	topModule := ctx.modulesFromName("A", nil)[0]
	ctx.walkDeps(topModule,
		func(dep depInfo, parent *moduleInfo) bool {
			if dep.module.logicModule.(Walker).Walk() {
				outputDown += ctx.ModuleName(dep.module.logicModule)
				return true
			}
			return false
		},
		func(dep depInfo, parent *moduleInfo) {
			if dep.module.logicModule.(Walker).Walk() {
				outputUp += ctx.ModuleName(dep.module.logicModule)
			}
		})
	if outputDown != "CFG" {
		t.Fatalf("unexpected walkDeps behaviour: %s\ndown should be: CFG", outputDown)
	}
	if outputUp != "GFC" {
		t.Fatalf("unexpected walkDeps behaviour: %s\nup should be: GFC", outputUp)
	}
}

func TestCreateModule(t *testing.T) {
	ctx := newContext()
	ctx.MockFileSystem(map[string][]byte{
		"Blueprints": []byte(`
			foo_module {
			    name: "A",
			    deps: ["B", "C"],
			}
		`),
	})

	ctx.RegisterTopDownMutator("create", createTestMutator)
	ctx.RegisterBottomUpMutator("deps", blueprintDepsMutator)

	ctx.RegisterModuleType("foo_module", newFooModule)
	ctx.RegisterModuleType("bar_module", newBarModule)
	_, errs := ctx.ParseBlueprintsFiles("Blueprints")
	if len(errs) > 0 {
		t.Errorf("unexpected parse errors:")
		for _, err := range errs {
			t.Errorf("  %s", err)
		}
		t.FailNow()
	}

	_, errs = ctx.ResolveDependencies(nil)
	if len(errs) > 0 {
		t.Errorf("unexpected dep errors:")
		for _, err := range errs {
			t.Errorf("  %s", err)
		}
		t.FailNow()
	}

	a := ctx.modulesFromName("A", nil)[0].logicModule.(*fooModule)
	b := ctx.modulesFromName("B", nil)[0].logicModule.(*barModule)
	c := ctx.modulesFromName("C", nil)[0].logicModule.(*barModule)
	d := ctx.modulesFromName("D", nil)[0].logicModule.(*fooModule)

	checkDeps := func(m Module, expected string) {
		var deps []string
		ctx.VisitDirectDeps(m, func(m Module) {
			deps = append(deps, ctx.ModuleName(m))
		})
		got := strings.Join(deps, ",")
		if got != expected {
			t.Errorf("unexpected %q dependencies, got %q expected %q",
				ctx.ModuleName(m), got, expected)
		}
	}

	checkDeps(a, "B,C")
	checkDeps(b, "D")
	checkDeps(c, "D")
	checkDeps(d, "")
}

func createTestMutator(ctx TopDownMutatorContext) {
	type props struct {
		Name string
		Deps []string
	}

	ctx.CreateModule(newBarModule, &props{
		Name: "B",
		Deps: []string{"D"},
	})

	ctx.CreateModule(newBarModule, &props{
		Name: "C",
		Deps: []string{"D"},
	})

	ctx.CreateModule(newFooModule, &props{
		Name: "D",
	})
}

func TestWalkFileOrder(t *testing.T) {
	// Run the test once to see how long it normally takes
	start := time.Now()
	doTestWalkFileOrder(t, time.Duration(0))
	duration := time.Since(start)

	// Run the test again, but put enough of a sleep into each visitor to detect ordering
	// problems if they exist
	doTestWalkFileOrder(t, duration)
}

// test that WalkBlueprintsFiles calls asyncVisitor in the right order
func doTestWalkFileOrder(t *testing.T, sleepDuration time.Duration) {
	// setup mock context
	ctx := newContext()
	mockFiles := map[string][]byte{
		"Blueprints": []byte(`
			sample_module {
			    name: "a",
			}
		`),
		"dir1/Blueprints": []byte(`
			sample_module {
			    name: "b",
			}
		`),
		"dir1/dir2/Blueprints": []byte(`
			sample_module {
			    name: "c",
			}
		`),
	}
	ctx.MockFileSystem(mockFiles)

	// prepare to monitor the visit order
	visitOrder := []string{}
	visitLock := sync.Mutex{}
	correctVisitOrder := []string{"Blueprints", "dir1/Blueprints", "dir1/dir2/Blueprints"}

	// sleep longer when processing the earlier files
	chooseSleepDuration := func(fileName string) (duration time.Duration) {
		duration = time.Duration(0)
		for i := len(correctVisitOrder) - 1; i >= 0; i-- {
			if fileName == correctVisitOrder[i] {
				return duration
			}
			duration = duration + sleepDuration
		}
		panic("unrecognized file name " + fileName)
	}

	visitor := func(file *parser.File) {
		time.Sleep(chooseSleepDuration(file.Name))
		visitLock.Lock()
		defer visitLock.Unlock()
		visitOrder = append(visitOrder, file.Name)
	}
	keys := []string{"Blueprints", "dir1/Blueprints", "dir1/dir2/Blueprints"}

	// visit the blueprints files
	ctx.WalkBlueprintsFiles(".", keys, visitor)

	// check the order
	if !reflect.DeepEqual(visitOrder, correctVisitOrder) {
		t.Errorf("Incorrect visit order; expected %v, got %v", correctVisitOrder, visitOrder)
	}
}

// test that WalkBlueprintsFiles reports syntax errors
func TestWalkingWithSyntaxError(t *testing.T) {
	// setup mock context
	ctx := newContext()
	mockFiles := map[string][]byte{
		"Blueprints": []byte(`
			sample_module {
			    name: "a" "b",
			}
		`),
		"dir1/Blueprints": []byte(`
			sample_module {
			    name: "b",
		`),
		"dir1/dir2/Blueprints": []byte(`
			sample_module {
			    name: "c",
			}
		`),
	}
	ctx.MockFileSystem(mockFiles)

	keys := []string{"Blueprints", "dir1/Blueprints", "dir1/dir2/Blueprints"}

	// visit the blueprints files
	_, errs := ctx.WalkBlueprintsFiles(".", keys, func(file *parser.File) {})

	expectedErrs := []error{
		errors.New(`Blueprints:3:18: expected "}", found String`),
		errors.New(`dir1/Blueprints:4:3: expected "}", found EOF`),
	}
	if fmt.Sprintf("%s", expectedErrs) != fmt.Sprintf("%s", errs) {
		t.Errorf("Incorrect errors; expected:\n%s\ngot:\n%s", expectedErrs, errs)
	}

}