// Copyright 2017, Pulumi Corporation.  All rights reserved.

package engine

import (
	"bytes"
	"fmt"
	"time"

	goerr "github.com/pkg/errors"

	"github.com/pulumi/pulumi/pkg/compiler/errors"
	"github.com/pulumi/pulumi/pkg/diag"
	"github.com/pulumi/pulumi/pkg/diag/colors"
	"github.com/pulumi/pulumi/pkg/resource"
	"github.com/pulumi/pulumi/pkg/resource/deploy"
	"github.com/pulumi/pulumi/pkg/tokens"
	"github.com/pulumi/pulumi/pkg/util/contract"
)

type DeployOptions struct {
	Package              string   // the package we are deploying (or "" to use the default)
	Analyzers            []string // an optional set of analyzers to run as part of this deployment.
	DryRun               bool     // true if we should just print the plan without performing it.
	Parallel             int      // the degree of parallelism for resource operations (<=1 for serial).
	ShowConfig           bool     // true to show the configuration variables being used.
	ShowReplacementSteps bool     // true to show the replacement steps in the plan.
	ShowSames            bool     // true to show the resources that aren't updated, in addition to those that are.
	Summary              bool     // true if we should only summarize resources and operations.
}

func (eng *Engine) Deploy(stack tokens.QName, events chan<- Event, opts DeployOptions) error {
	contract.Require(stack != tokens.QName(""), "stack")
	contract.Require(events != nil, "events")

	defer func() { events <- cancelEvent() }()

	info, err := eng.planContextFromStack(stack, opts.Package)
	if err != nil {
		return err
	}
	defer info.Close()

	return eng.deployLatest(info, deployOptions{
		Destroy:              false,
		DryRun:               opts.DryRun,
		Analyzers:            opts.Analyzers,
		Parallel:             opts.Parallel,
		ShowConfig:           opts.ShowConfig,
		ShowReplacementSteps: opts.ShowReplacementSteps,
		ShowSames:            opts.ShowSames,
		Summary:              opts.Summary,
		Events:               events,
		Diag: newEventSink(events, diag.FormatOptions{
			Colors: true,
		}),
	})
}

type deployOptions struct {
	Create               bool         // true if we are creating resources.
	Destroy              bool         // true if we are destroying the stack.
	DryRun               bool         // true if we should just print the plan without performing it.
	Analyzers            []string     // an optional set of analyzers to run as part of this deployment.
	Parallel             int          // the degree of parallelism for resource operations (<=1 for serial).
	ShowConfig           bool         // true to show the configuration variables being used.
	ShowReplacementSteps bool         // true to show the replacement steps in the plan.
	ShowSames            bool         // true to show the resources that aren't updated, in addition to those that are.
	Summary              bool         // true if we should only summarize resources and operations.
	Detailed             bool         // true to show very detailed output, like properties that haven't changed.
	DOT                  bool         // true if we should print the DOT file for this plan.
	Events               chan<- Event // the channel to write events from the engine to.
	Diag                 diag.Sink    // the sink to use for diag'ing.
}

func (eng *Engine) deployLatest(info *planContext, opts deployOptions) error {
	result, err := eng.plan(info, opts)
	if err != nil {
		return err
	}
	if result != nil {
		defer contract.IgnoreClose(result)

		// Make the current working directory the same as the program's, and restore it upon exit.
		done, err := result.Chdir()
		if err != nil {
			return err
		}
		defer done()

		if opts.DryRun {
			// If a dry run, just print the plan, don't actually carry out the deployment.
			if err := eng.printPlan(result); err != nil {
				return err
			}
		} else {
			// Otherwise, we will actually deploy the latest bits.
			var header bytes.Buffer
			printPrelude(&header, result, false)
			header.WriteString(fmt.Sprintf("%vPerforming changes:%v\n", colors.SpecUnimportant, colors.Reset))
			opts.Events <- stdOutEventWithColor(&header)

			// Walk the plan, reporting progress and executing the actual operations as we go.
			start := time.Now()
			actions := newDeployActions(opts, result.Info.Target, eng)
			summary, _, _, err := result.Walk(actions, false)
			if err != nil && summary == nil {
				// Something went wrong, and no changes were made.
				return err
			}
			contract.Assert(summary != nil)

			// Print a summary.
			var footer bytes.Buffer

			// Print out the total number of steps performed (and their kinds), the duration, and any summary info.
			if c := printChangeSummary(&footer, actions.Ops, false); c != 0 {
				footer.WriteString(fmt.Sprintf("%vUpdate duration: %v%v\n",
					colors.SpecUnimportant, time.Since(start), colors.Reset))
			}

			if actions.MaybeCorrupt {
				footer.WriteString(fmt.Sprintf(
					"%vA catastrophic error occurred; resources states may be unknown%v\n",
					colors.SpecAttention, colors.Reset))
			}

			opts.Events <- stdOutEventWithColor(&footer)

			if err != nil {
				return err
			}
		}
	}
	if !opts.Diag.Success() {
		// If any error that wasn't printed above, be sure to make it evident in the output.
		return goerr.New("One or more errors occurred during this update")
	}
	return nil
}

// deployActions pretty-prints the plan application process as it goes.
type deployActions struct {
	Steps        int
	Ops          map[deploy.StepOp]int
	Seen         map[resource.URN]deploy.Step
	Shown        map[resource.URN]bool
	MaybeCorrupt bool
	Opts         deployOptions
	Target       *deploy.Target
	Engine       *Engine
}

func newDeployActions(opts deployOptions, target *deploy.Target, engine *Engine) *deployActions {
	return &deployActions{
		Ops:    make(map[deploy.StepOp]int),
		Seen:   make(map[resource.URN]deploy.Step),
		Shown:  make(map[resource.URN]bool),
		Opts:   opts,
		Target: target,
		Engine: engine,
	}
}

func (acts *deployActions) OnResourceStepPre(step deploy.Step) (interface{}, error) {
	// Report the beginning of the step if appropriate.
	if shouldShow(acts.Seen, step, acts.Opts) || isRootStack(step) {
		var b bytes.Buffer
		printStep(&b, step, acts.Seen, acts.Shown, acts.Opts.Summary, acts.Opts.Detailed, false, 0 /*indent*/)
		acts.Opts.Events <- stdOutEventWithColor(&b)
	}

	// Inform the snapshot service that we are about to perform a step.
	if step.Op() != deploy.OpSame {
		return acts.Engine.Snapshots.BeginMutation(acts.Target.Name)
	}
	return nil, nil
}

func (acts *deployActions) OnResourceStepPost(ctx interface{},
	step deploy.Step, status resource.Status, err error) error {
	var b bytes.Buffer

	// Report the result of the step.
	stepop := step.Op()
	if err != nil {
		// Issue a true, bonafide error.
		acts.Opts.Diag.Errorf(errors.ErrorPlanApplyFailed, err)

		// Print the state of the resource; we don't issue the error, because the deploy above will do that.
		stepnum := acts.Steps + 1
		b.WriteString(fmt.Sprintf("Step #%v failed [%v]: ", stepnum, stepop))
		switch status {
		case resource.StatusOK:
			b.WriteString(colors.SpecNote)
			b.WriteString("provider successfully recovered from this failure")
		case resource.StatusUnknown:
			b.WriteString(colors.SpecAttention)
			b.WriteString("this failure was catastrophic and the provider cannot guarantee recovery")
			acts.MaybeCorrupt = true
		default:
			contract.Failf("Unrecognized resource state: %v", status)
		}
		b.WriteString(colors.Reset)
		b.WriteString("\n")
	} else {
		if step.Logical() {
			// Increment the counters.
			acts.Steps++
			acts.Ops[stepop]++
		}

		// Also show outputs here, since there might be some from the initial registration.
		if shouldShow(acts.Seen, step, acts.Opts) && !acts.Opts.Summary {
			printResourceOutputProperties(&b, step, acts.Seen, acts.Shown, 0 /*indent*/)
		}
	}

	acts.Opts.Events <- stdOutEventWithColor(&b)

	// If necessary, write out the current snapshot. Note that even if a failure has occurred, we should still have a
	// safe checkpoint.  Note that any error that occurs when writing the checkpoint trumps the error reported above.
	if ctx != nil {
		return ctx.(SnapshotMutation).End(step.Iterator().Snap())
	}
	return nil
}

func (acts *deployActions) OnResourceOutputs(step deploy.Step) error {
	// Print this step's output properties.
	if (shouldShow(acts.Seen, step, acts.Opts) || isRootStack(step)) && !acts.Opts.Summary {
		var b bytes.Buffer
		printResourceOutputProperties(&b, step, acts.Seen, acts.Shown, 0 /*indent*/)
		acts.Opts.Events <- stdOutEventWithColor(&b)
	}

	// There's a chance there are new outputs that weren't written out last time.
	// We need to perform another snapshot write to ensure they get written out.
	mutation, err := acts.Engine.Snapshots.BeginMutation(acts.Target.Name)
	if err != nil {
		return err
	}
	if err = mutation.End(step.Iterator().Snap()); err != nil {
		return err
	}

	return nil
}