// Copyright 2016-2018, Pulumi Corporation.
//
// 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 httpstate

import (
	"context"
	"fmt"
	"time"

	"github.com/pulumi/pulumi/pkg/apitype"
	"github.com/pulumi/pulumi/pkg/backend"
	"github.com/pulumi/pulumi/pkg/backend/httpstate/client"
	"github.com/pulumi/pulumi/pkg/engine"
	"github.com/pulumi/pulumi/pkg/operations"
	"github.com/pulumi/pulumi/pkg/resource/deploy"
	"github.com/pulumi/pulumi/pkg/tokens"
	"github.com/pulumi/pulumi/pkg/util/contract"
	"github.com/pulumi/pulumi/pkg/util/result"
)

// Stack is a cloud stack.  This simply adds some cloud-specific properties atop the standard backend stack interface.
type Stack interface {
	backend.Stack
	CloudURL() string                      // the URL to the cloud containing this stack.
	OrgName() string                       // the organization that owns this stack.
	ConsoleURL() (string, error)           // the URL to view the stack's information on Pulumi.com
	Tags() map[apitype.StackTagName]string // the stack's tags.
	StackIdentifier() client.StackIdentifier
}

type cloudBackendReference struct {
	name    tokens.QName
	project string
	owner   string
	b       *cloudBackend
}

func (c cloudBackendReference) String() string {
	curUser, err := c.b.CurrentUser()
	if err != nil {
		curUser = ""
	}

	// If the project names match, we can elide them.
	if c.b.currentProject != nil && c.project == string(c.b.currentProject.Name) {
		if c.owner == curUser {
			return string(c.name) // Elide owner too, if it is the current user.
		}
		return fmt.Sprintf("%s/%s", c.owner, c.name)
	}

	return fmt.Sprintf("%s/%s/%s", c.owner, c.project, c.name)
}

func (c cloudBackendReference) Name() tokens.QName {
	return c.name
}

// cloudStack is a cloud stack descriptor.
type cloudStack struct {
	// ref is the stack's unique name.
	ref cloudBackendReference
	// cloudURL is the URl to the cloud containing this stack.
	cloudURL string
	// orgName is the organization that owns this stack.
	orgName string
	// snapshot contains the latest deployment state, allocated on first use.
	snapshot **deploy.Snapshot
	// b is a pointer to the backend that this stack belongs to.
	b *cloudBackend
	// tags contains metadata tags describing additional, extensible properties about this stack.
	tags map[apitype.StackTagName]string
}

func newStack(apistack apitype.Stack, b *cloudBackend) Stack {
	// Now assemble all the pieces into a stack structure.
	return &cloudStack{
		ref: cloudBackendReference{
			owner:   apistack.OrgName,
			project: apistack.ProjectName,
			name:    apistack.StackName,
			b:       b,
		},
		cloudURL: b.CloudURL(),
		orgName:  apistack.OrgName,
		snapshot: nil, // We explicitly allocate the snapshot on first use, since it is expensive to compute.
		tags:     apistack.Tags,
		b:        b,
	}
}
func (s *cloudStack) Ref() backend.StackReference           { return s.ref }
func (s *cloudStack) Backend() backend.Backend              { return s.b }
func (s *cloudStack) CloudURL() string                      { return s.cloudURL }
func (s *cloudStack) OrgName() string                       { return s.orgName }
func (s *cloudStack) Tags() map[apitype.StackTagName]string { return s.tags }

func (s *cloudStack) StackIdentifier() client.StackIdentifier {

	si, err := s.b.getCloudStackIdentifier(s.ref)
	contract.AssertNoError(err) // the above only fails when ref is of the wrong type.
	return si
}

func (s *cloudStack) Snapshot(ctx context.Context) (*deploy.Snapshot, error) {
	if s.snapshot != nil {
		return *s.snapshot, nil
	}

	snap, err := s.b.getSnapshot(ctx, s.ref)
	if err != nil {
		return nil, err
	}

	s.snapshot = &snap
	return *s.snapshot, nil
}

func (s *cloudStack) Remove(ctx context.Context, force bool) (bool, error) {
	return backend.RemoveStack(ctx, s, force)
}

func (s *cloudStack) Rename(ctx context.Context, newName tokens.QName) error {
	return backend.RenameStack(ctx, s, newName)
}

func (s *cloudStack) Preview(ctx context.Context, op backend.UpdateOperation) (engine.ResourceChanges, result.Result) {
	return backend.PreviewStack(ctx, s, op)
}

func (s *cloudStack) Update(ctx context.Context, op backend.UpdateOperation) (engine.ResourceChanges, result.Result) {
	return backend.UpdateStack(ctx, s, op)
}

func (s *cloudStack) Refresh(ctx context.Context, op backend.UpdateOperation) (engine.ResourceChanges, result.Result) {
	return backend.RefreshStack(ctx, s, op)
}

func (s *cloudStack) Destroy(ctx context.Context, op backend.UpdateOperation) (engine.ResourceChanges, result.Result) {
	return backend.DestroyStack(ctx, s, op)
}

func (s *cloudStack) GetLogs(ctx context.Context, cfg backend.StackConfiguration,
	query operations.LogQuery) ([]operations.LogEntry, error) {
	return backend.GetStackLogs(ctx, s, cfg, query)
}

func (s *cloudStack) ExportDeployment(ctx context.Context) (*apitype.UntypedDeployment, error) {
	return backend.ExportStackDeployment(ctx, s)
}

func (s *cloudStack) ImportDeployment(ctx context.Context, deployment *apitype.UntypedDeployment) error {
	return backend.ImportStackDeployment(ctx, s, deployment)
}

func (s *cloudStack) ConsoleURL() (string, error) {
	return s.b.StackConsoleURL(s.ref)
}

// cloudStackSummary implements the backend.StackSummary interface, by wrapping
// an apitype.StackSummary struct.
type cloudStackSummary struct {
	summary apitype.StackSummary
	b       *cloudBackend
}

func (css cloudStackSummary) Name() backend.StackReference {
	contract.Assert(css.summary.ProjectName != "")

	return cloudBackendReference{
		owner:   css.summary.OrgName,
		project: css.summary.ProjectName,
		name:    tokens.QName(css.summary.StackName),
		b:       css.b,
	}
}

func (css cloudStackSummary) LastUpdate() *time.Time {
	if css.summary.LastUpdate == nil {
		return nil
	}
	t := time.Unix(*css.summary.LastUpdate, 0)
	return &t
}

func (css cloudStackSummary) ResourceCount() *int {
	return css.summary.ResourceCount
}