package v2

import (
	"context"
	"encoding/base64"
	"errors"
	"fmt"
	"os"
	"os/signal"
	"path/filepath"
	"strconv"
	"syscall"
	"time"

	"github.com/porter-dev/porter/api/server/handlers/porter_app"
	"github.com/porter-dev/porter/api/types"
	"github.com/porter-dev/porter/internal/models"

	"github.com/fatih/color"
	api "github.com/porter-dev/porter/api/client"
	"github.com/porter-dev/porter/cli/cmd/config"
)

// UpdateInput is the input for the Update function
type UpdateInput struct {
	// CLIConfig is the CLI configuration
	CLIConfig config.CLIConfig
	// Client is the Porter API client
	Client api.Client
	// PorterYamlPath is the path to the porter.yaml file
	PorterYamlPath string
	// AppName is the name of the app
	AppName string
	// PreviewApply is true when Update should create a new deployment target matching current git branch and apply to that target
	PreviewApply bool
}

// Update implements the functionality of the `porter apply` command for validate apply v2 projects
func Update(ctx context.Context, inp UpdateInput) error {
	ctx, cancel := context.WithCancel(ctx)
	defer cancel()

	go func() {
		termChan := make(chan os.Signal, 1)
		signal.Notify(termChan, syscall.SIGINT, syscall.SIGTERM)
		select {
		case <-termChan:
			color.New(color.FgYellow).Printf("Shutdown signal received, cancelling processes\n") // nolint:errcheck,gosec
			cancel()
		case <-ctx.Done():
		}
	}()

	cliConf := inp.CLIConfig
	client := inp.Client

	deploymentTargetID, err := deploymentTargetFromConfig(ctx, client, cliConf.Project, cliConf.Cluster, inp.PreviewApply)
	if err != nil {
		return fmt.Errorf("error getting deployment target from config: %w", err)
	}

	var prNumber int
	prNumberEnv := os.Getenv("PORTER_PR_NUMBER")
	if prNumberEnv != "" {
		prNumber, err = strconv.Atoi(prNumberEnv)
		if err != nil {
			return fmt.Errorf("error parsing PORTER_PR_NUMBER to int: %w", err)
		}
	}

	porterYamlExists := len(inp.PorterYamlPath) != 0

	if porterYamlExists {
		_, err := os.Stat(filepath.Clean(inp.PorterYamlPath))
		if err != nil {
			if !os.IsNotExist(err) {
				return fmt.Errorf("error checking if porter yaml exists at path %s: %w", inp.PorterYamlPath, err)
			}
			// If a path was specified but the file does not exist, we will not immediately error out.
			// This supports users migrated from v1 who use a workflow file that always specifies a porter yaml path
			// in the apply command.
			porterYamlExists = false
		}
	}

	var b64YAML string
	if porterYamlExists {
		porterYaml, err := os.ReadFile(filepath.Clean(inp.PorterYamlPath))
		if err != nil {
			return fmt.Errorf("could not read porter yaml file: %w", err)
		}

		b64YAML = base64.StdEncoding.EncodeToString(porterYaml)
		color.New(color.FgGreen).Printf("Using Porter YAML at path: %s\n", inp.PorterYamlPath) // nolint:errcheck,gosec
	}

	commitSHA := commitSHAFromEnv()
	gitSource, err := gitSourceFromEnv()
	if err != nil {
		return fmt.Errorf("error getting git source from env: %w", err)
	}

	updateInput := api.UpdateAppInput{
		ProjectID:          cliConf.Project,
		ClusterID:          cliConf.Cluster,
		Name:               inp.AppName,
		GitSource:          gitSource,
		DeploymentTargetId: deploymentTargetID,
		Base64PorterYAML:   b64YAML,
		CommitSHA:          commitSHA,
	}

	updateResp, err := client.UpdateApp(ctx, updateInput)
	if err != nil {
		return fmt.Errorf("error calling update app endpoint: %w", err)
	}

	if updateResp.AppRevisionId == "" {
		return errors.New("app revision id is empty")
	}

	appName := updateResp.AppName

	buildSettings, err := client.GetBuildFromRevision(ctx, cliConf.Project, cliConf.Cluster, appName, updateResp.AppRevisionId)
	if err != nil {
		return fmt.Errorf("error getting build from revision: %w", err)
	}

	if buildSettings != nil && buildSettings.Build.Method != "" {
		eventID, _ := createBuildEvent(ctx, client, appName, cliConf.Project, cliConf.Cluster, deploymentTargetID, commitSHA)

		var buildFinished bool
		var buildError error
		var buildLogs string

		defer func() {
			if buildError != nil && !errors.Is(buildError, context.Canceled) {
				reportBuildFailureInput := reportBuildFailureInput{
					client:             client,
					appName:            appName,
					cliConf:            cliConf,
					deploymentTargetID: deploymentTargetID,
					appRevisionID:      updateResp.AppRevisionId,
					eventID:            eventID,
					commitSHA:          commitSHA,
					prNumber:           prNumber,
					buildError:         buildError,
					buildLogs:          buildLogs,
				}
				_ = reportBuildFailure(ctx, reportBuildFailureInput)
				return
			}
			if !buildFinished {
				buildMetadata := make(map[string]interface{})
				buildMetadata["end_time"] = time.Now().UTC()
				_ = updateExistingEvent(ctx, client, appName, cliConf.Project, cliConf.Cluster, deploymentTargetID, types.PorterAppEventType_Build, eventID, types.PorterAppEventStatus_Canceled, buildMetadata)
				return
			}
		}()

		if commitSHA == "" {
			return errors.New("build is required but commit SHA cannot be identified. Please set the PORTER_COMMIT_SHA environment variable or run apply in git repository with access to the git CLI")
		}

		color.New(color.FgGreen).Printf("Building new image with tag %s...\n", commitSHA) // nolint:errcheck,gosec

		buildInput, err := buildInputFromBuildSettings(buildInputFromBuildSettingsInput{
			projectID: cliConf.Project,
			appName:   appName,
			commitSHA: commitSHA,
			image:     buildSettings.Image,
			build:     buildSettings.Build,
			buildEnv:  buildSettings.BuildEnvVariables,
		})
		if err != nil {
			buildError = fmt.Errorf("error creating build input from build settings: %w", err)
			return buildError
		}

		buildOutput := build(ctx, client, buildInput)
		if buildOutput.Error != nil {
			buildError = fmt.Errorf("error building app: %w", buildOutput.Error)
			buildLogs = buildOutput.Logs
			return buildError
		}

		_, err = client.UpdateRevisionStatus(ctx, cliConf.Project, cliConf.Cluster, appName, updateResp.AppRevisionId, models.AppRevisionStatus_BuildSuccessful)
		if err != nil {
			buildError = fmt.Errorf("error updating revision status post build: %w", err)
			return buildError
		}

		color.New(color.FgGreen).Printf("Successfully built image (tag: %s)\n", commitSHA) // nolint:errcheck,gosec

		buildMetadata := make(map[string]interface{})
		buildMetadata["end_time"] = time.Now().UTC()
		_ = updateExistingEvent(ctx, client, appName, cliConf.Project, cliConf.Cluster, deploymentTargetID, types.PorterAppEventType_Build, eventID, types.PorterAppEventStatus_Success, buildMetadata)
		buildFinished = true
	}

	color.New(color.FgGreen).Printf("Deploying new revision %s for app %s...\n", updateResp.AppRevisionId, appName) // nolint:errcheck,gosec

	now := time.Now().UTC()

	for {
		if time.Since(now) > checkDeployTimeout {
			return errors.New("timed out waiting for app to deploy")
		}

		status, err := client.GetRevisionStatus(ctx, cliConf.Project, cliConf.Cluster, appName, updateResp.AppRevisionId)
		if err != nil {
			return fmt.Errorf("error getting app revision status: %w", err)
		}

		if status == nil {
			return errors.New("unable to determine status of app revision")
		}

		if status.AppRevisionStatus.IsInTerminalStatus {
			break
		}

		if status.AppRevisionStatus.PredeployStarted {
			color.New(color.FgGreen).Printf("Waiting for predeploy to complete...\n") // nolint:errcheck,gosec
		}

		if status.AppRevisionStatus.InstallStarted {
			color.New(color.FgGreen).Printf("Waiting for deploy to complete...\n") // nolint:errcheck,gosec
		}

		time.Sleep(checkDeployFrequency)
	}

	_, _ = client.ReportRevisionStatus(ctx, api.ReportRevisionStatusInput{
		ProjectID:     cliConf.Project,
		ClusterID:     cliConf.Cluster,
		AppName:       appName,
		AppRevisionID: updateResp.AppRevisionId,
		PRNumber:      prNumber,
		CommitSHA:     commitSHA,
	})

	status, err := client.GetRevisionStatus(ctx, cliConf.Project, cliConf.Cluster, appName, updateResp.AppRevisionId)
	if err != nil {
		return fmt.Errorf("error getting app revision status: %w", err)
	}

	if status == nil {
		return errors.New("unable to determine status of app revision")
	}

	if status.AppRevisionStatus.InstallFailed {
		return errors.New("app failed to deploy")
	}
	if status.AppRevisionStatus.PredeployFailed {
		return errors.New("predeploy failed for new revision")
	}

	color.New(color.FgGreen).Printf("Successfully applied new revision %s\n", updateResp.AppRevisionId) // nolint:errcheck,gosec
	return nil
}

// checkDeployTimeout is the timeout for checking if an app has been deployed
const checkDeployTimeout = 15 * time.Minute

// checkDeployFrequency is the frequency for checking if an app has been deployed
const checkDeployFrequency = 10 * time.Second

func gitSourceFromEnv() (porter_app.GitSource, error) {
	var source porter_app.GitSource

	var repoID uint
	if os.Getenv("GITHUB_REPOSITORY_ID") != "" {
		id, err := strconv.Atoi(os.Getenv("GITHUB_REPOSITORY_ID"))
		if err != nil {
			return source, fmt.Errorf("unable to parse GITHUB_REPOSITORY_ID to int: %w", err)
		}
		repoID = uint(id)
	}

	return porter_app.GitSource{
		GitBranch:   os.Getenv("GITHUB_REF_NAME"),
		GitRepoID:   repoID,
		GitRepoName: os.Getenv("GITHUB_REPOSITORY"),
	}, nil
}

type buildInputFromBuildSettingsInput struct {
	projectID uint
	appName   string
	commitSHA string
	image     porter_app.Image
	build     porter_app.BuildSettings
	buildEnv  map[string]string
}

func buildInputFromBuildSettings(inp buildInputFromBuildSettingsInput) (buildInput, error) {
	var buildSettings buildInput

	if inp.appName == "" {
		return buildSettings, errors.New("app name is empty")
	}
	if inp.image.Repository == "" {
		return buildSettings, errors.New("image repository is empty")
	}
	if inp.build.Method == "" {
		return buildSettings, errors.New("build method is empty")
	}
	if inp.commitSHA == "" {
		return buildSettings, errors.New("commit SHA is empty")
	}

	return buildInput{
		ProjectID:       inp.projectID,
		AppName:         inp.appName,
		BuildContext:    inp.build.Context,
		Dockerfile:      inp.build.Dockerfile,
		BuildMethod:     inp.build.Method,
		Builder:         inp.build.Builder,
		BuildPacks:      inp.build.Buildpacks,
		ImageTag:        inp.commitSHA,
		RepositoryURL:   inp.image.Repository,
		CurrentImageTag: inp.image.Tag,
		Env:             inp.buildEnv,
	}, nil
}