package events

import (
	"fmt"
	"os"
	"path/filepath"

	"github.com/pkg/errors"
	"github.com/runatlantis/atlantis/server/events/models"
	"github.com/runatlantis/atlantis/server/events/run"
	"github.com/runatlantis/atlantis/server/events/terraform"
	"github.com/runatlantis/atlantis/server/events/vcs"
	"github.com/runatlantis/atlantis/server/events/webhooks"
)

// ApplyExecutor handles executing terraform apply.
type ApplyExecutor struct {
	VCSClient         vcs.ClientProxy
	Terraform         *terraform.DefaultClient
	RequireApproval   bool
	Run               *run.Run
	AtlantisWorkspace AtlantisWorkspace
	ProjectPreExecute *DefaultProjectPreExecutor
	Webhooks          webhooks.Sender
}

// Execute executes apply for the ctx.
func (a *ApplyExecutor) Execute(ctx *CommandContext) CommandResponse {
	if a.RequireApproval {
		approved, err := a.VCSClient.PullIsApproved(ctx.BaseRepo, ctx.Pull, ctx.VCSHost)
		if err != nil {
			return CommandResponse{Error: errors.Wrap(err, "checking if pull request was approved")}
		}
		if !approved {
			return CommandResponse{Failure: "Pull request must be approved before running apply."}
		}
		ctx.Log.Info("confirmed pull request was approved")
	}

	repoDir, err := a.AtlantisWorkspace.GetWorkspace(ctx.BaseRepo, ctx.Pull, ctx.Command.Workspace)
	if err != nil {
		return CommandResponse{Failure: "No workspace found. Did you run plan?"}
	}
	ctx.Log.Info("found workspace in %q", repoDir)

	// Plans are stored at project roots by their workspace names. We just
	// need to find them.
	var plans []models.Plan
	// If they didn't specify a directory, we apply all plans we can find for
	// this workspace.
	if ctx.Command.Dir == "" {
		err = filepath.Walk(repoDir, func(path string, info os.FileInfo, err error) error {
			if err != nil {
				return err
			}
			// Check if the plan is for the right workspace,
			if !info.IsDir() && info.Name() == ctx.Command.Workspace+".tfplan" {
				rel, _ := filepath.Rel(repoDir, filepath.Dir(path))
				plans = append(plans, models.Plan{
					Project:   models.NewProject(ctx.BaseRepo.FullName, rel),
					LocalPath: path,
				})
			}
			return nil
		})
		if err != nil {
			return CommandResponse{Error: errors.Wrap(err, "finding plans")}
		}
	} else {
		// If they did specify a dir, we apply just the plan in that directory
		// for this workspace.
		path := filepath.Join(repoDir, ctx.Command.Dir, ctx.Command.Workspace+".tfplan")
		stat, err := os.Stat(path)
		if err != nil || stat.IsDir() {
			return CommandResponse{Error: errors.Wrapf(err, "finding plan for dir %q and workspace %q", ctx.Command.Dir, ctx.Command.Workspace)}
		}
		rel, _ := filepath.Rel(repoDir, filepath.Dir(path))
		plans = append(plans, models.Plan{
			Project:   models.NewProject(ctx.BaseRepo.FullName, filepath.Dir(rel)),
			LocalPath: path,
		})
	}
	if len(plans) == 0 {
		return CommandResponse{Failure: "No plans found for that workspace."}
	}
	var paths []string
	for _, p := range plans {
		paths = append(paths, p.LocalPath)
	}
	ctx.Log.Info("found %d plan(s) in our workspace: %v", len(plans), paths)

	var results []ProjectResult
	for _, plan := range plans {
		ctx.Log.Info("running apply for project at path %q", plan.Project.Path)
		result := a.apply(ctx, repoDir, plan)
		result.Path = plan.LocalPath
		results = append(results, result)
	}
	return CommandResponse{ProjectResults: results}
}

func (a *ApplyExecutor) apply(ctx *CommandContext, repoDir string, plan models.Plan) ProjectResult {
	preExecute := a.ProjectPreExecute.Execute(ctx, repoDir, plan.Project)
	if preExecute.ProjectResult != (ProjectResult{}) {
		return preExecute.ProjectResult
	}
	config := preExecute.ProjectConfig
	terraformVersion := preExecute.TerraformVersion

	applyExtraArgs := config.GetExtraArguments(ctx.Command.Name.String())
	absolutePath := filepath.Join(repoDir, plan.Project.Path)
	workspace := ctx.Command.Workspace
	tfApplyCmd := append(append(append([]string{"apply", "-no-color"}, applyExtraArgs...), ctx.Command.Flags...), plan.LocalPath)
	output, err := a.Terraform.RunCommandWithVersion(ctx.Log, absolutePath, tfApplyCmd, terraformVersion, workspace)

	a.Webhooks.Send(ctx.Log, webhooks.ApplyResult{ // nolint: errcheck
		Workspace: workspace,
		User:      ctx.User,
		Repo:      ctx.BaseRepo,
		Pull:      ctx.Pull,
		Success:   err == nil,
	})

	if err != nil {
		return ProjectResult{Error: fmt.Errorf("%s\n%s", err.Error(), output)}
	}
	ctx.Log.Info("apply succeeded")

	if len(config.PostApply) > 0 {
		_, err := a.Run.Execute(ctx.Log, config.PostApply, absolutePath, workspace, terraformVersion, "post_apply")
		if err != nil {
			return ProjectResult{Error: errors.Wrap(err, "running post apply commands")}
		}
	}

	return ProjectResult{ApplySuccess: output}
}