package config

import (
	"fmt"
	"html/template"
	"io/ioutil"
	"os"
	"path"
	"strings"

	"coopcloud.tech/abra/pkg/formatter"
	"coopcloud.tech/abra/pkg/upstream/convert"
	loader "coopcloud.tech/abra/pkg/upstream/stack"
	stack "coopcloud.tech/abra/pkg/upstream/stack"
	composetypes "github.com/docker/cli/cli/compose/types"
	"github.com/docker/docker/api/types/filters"
	"github.com/sirupsen/logrus"
)

// Type aliases to make code hints easier to understand

// AppEnv is a map of the values in an apps env config
type AppEnv = map[string]string

// AppName is AppName
type AppName = string

// AppFile represents app env files on disk without reading the contents
type AppFile struct {
	Path   string
	Server string
}

// AppFiles is a slice of appfiles
type AppFiles map[AppName]AppFile

// App reprents an app with its env file read into memory
type App struct {
	Name   AppName
	Recipe string
	Domain string
	Env    AppEnv
	Server string
	Path   string
}

// StackName gets what the docker safe stack name is for the app. This should
// not not shown to the user, use a.Name for that. Give the output of this
// command to Docker only.
func (a App) StackName() string {
	if _, exists := a.Env["STACK_NAME"]; exists {
		return a.Env["STACK_NAME"]
	}

	stackName := SanitiseAppName(a.Name)

	if len(stackName) > 45 {
		logrus.Debugf("trimming %s to %s to avoid runtime limits", stackName, stackName[:45])
		stackName = stackName[:45]
	}

	a.Env["STACK_NAME"] = stackName

	return stackName
}

// Filters retrieves exact app filters for querying the container runtime. Due
// to upstream issues, filtering works different depending on what you're
// querying. So, for example, secrets don't work with regex! The caller needs
// to implement their own validation that the right secrets are matched. In
// order to handle these cases, we provide the `appendServiceNames` /
// `exactMatch` modifiers.
func (a App) Filters(appendServiceNames, exactMatch bool) (filters.Args, error) {
	filters := filters.NewArgs()

	composeFiles, err := GetAppComposeFiles(a.Recipe, a.Env)
	if err != nil {
		return filters, err
	}

	opts := stack.Deploy{Composefiles: composeFiles}
	compose, err := GetAppComposeConfig(a.Recipe, opts, a.Env)
	if err != nil {
		return filters, err
	}

	for _, service := range compose.Services {
		var filter string

		if appendServiceNames {
			if exactMatch {
				filter = fmt.Sprintf("^%s_%s", a.StackName(), service.Name)
			} else {
				filter = fmt.Sprintf("%s_%s", a.StackName(), service.Name)
			}
		} else {
			if exactMatch {
				filter = fmt.Sprintf("^%s", a.StackName())
			} else {
				filter = fmt.Sprintf("%s", a.StackName())
			}
		}

		filters.Add("name", filter)
	}

	return filters, nil
}

// ByServer sort a slice of Apps
type ByServer []App

func (a ByServer) Len() int      { return len(a) }
func (a ByServer) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
func (a ByServer) Less(i, j int) bool {
	return strings.ToLower(a[i].Server) < strings.ToLower(a[j].Server)
}

// ByServerAndRecipe sort a slice of Apps
type ByServerAndRecipe []App

func (a ByServerAndRecipe) Len() int      { return len(a) }
func (a ByServerAndRecipe) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
func (a ByServerAndRecipe) Less(i, j int) bool {
	if a[i].Server == a[j].Server {
		return strings.ToLower(a[i].Recipe) < strings.ToLower(a[j].Recipe)
	}
	return strings.ToLower(a[i].Server) < strings.ToLower(a[j].Server)
}

// ByRecipe sort a slice of Apps
type ByRecipe []App

func (a ByRecipe) Len() int      { return len(a) }
func (a ByRecipe) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
func (a ByRecipe) Less(i, j int) bool {
	return strings.ToLower(a[i].Recipe) < strings.ToLower(a[j].Recipe)
}

// ByName sort a slice of Apps
type ByName []App

func (a ByName) Len() int      { return len(a) }
func (a ByName) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
func (a ByName) Less(i, j int) bool {
	return strings.ToLower(a[i].Name) < strings.ToLower(a[j].Name)
}

func readAppEnvFile(appFile AppFile, name AppName) (App, error) {
	env, err := ReadEnv(appFile.Path)
	if err != nil {
		return App{}, fmt.Errorf("env file for %s couldn't be read: %s", name, err.Error())
	}

	logrus.Debugf("read env %s from %s", env, appFile.Path)

	app, err := newApp(env, name, appFile)
	if err != nil {
		return App{}, fmt.Errorf("env file for %s has issues: %s", name, err.Error())
	}

	return app, nil
}

// newApp creates new App object
func newApp(env AppEnv, name string, appFile AppFile) (App, error) {
	domain := env["DOMAIN"]

	recipe, exists := env["RECIPE"]
	if !exists {
		recipe, exists = env["TYPE"]
		if !exists {
			return App{}, fmt.Errorf("%s is missing the RECIPE env var", name)
		}
	}

	return App{
		Name:   name,
		Domain: domain,
		Recipe: recipe,
		Env:    env,
		Server: appFile.Server,
		Path:   appFile.Path,
	}, nil
}

// LoadAppFiles gets all app files for a given set of servers or all servers
func LoadAppFiles(servers ...string) (AppFiles, error) {
	appFiles := make(AppFiles)
	if len(servers) == 1 {
		if servers[0] == "" {
			// Empty servers flag, one string will always be passed
			var err error
			servers, err = GetAllFoldersInDirectory(SERVERS_DIR)
			if err != nil {
				return nil, err
			}
		}
	}

	logrus.Debugf("collecting metadata from %v servers: %s", len(servers), strings.Join(servers, ", "))

	for _, server := range servers {
		serverDir := path.Join(SERVERS_DIR, server)
		files, err := getAllFilesInDirectory(serverDir)
		if err != nil {
			return nil, fmt.Errorf("server %s doesn't exist? Run \"abra server ls\" to check", server)
		}
		for _, file := range files {
			appName := strings.TrimSuffix(file.Name(), ".env")
			appFilePath := path.Join(SERVERS_DIR, server, file.Name())
			appFiles[appName] = AppFile{
				Path:   appFilePath,
				Server: server,
			}
		}
	}
	return appFiles, nil
}

// GetApp loads an apps settings, reading it from file, in preparation to use it
//
// ONLY use when ready to use the env file to keep IO down
func GetApp(apps AppFiles, name AppName) (App, error) {
	appFile, exists := apps[name]
	if !exists {
		return App{}, fmt.Errorf("cannot find app with name %s", name)
	}

	app, err := readAppEnvFile(appFile, name)
	if err != nil {
		return App{}, err
	}

	return app, nil
}

// GetApps returns a slice of Apps with their env files read from a given slice of AppFiles
func GetApps(appFiles AppFiles) ([]App, error) {
	var apps []App

	for name := range appFiles {
		app, err := GetApp(appFiles, name)
		if err != nil {
			return nil, err
		}
		apps = append(apps, app)
	}

	return apps, nil
}

// GetAppServiceNames retrieves a list of app service names.
func GetAppServiceNames(appName string) ([]string, error) {
	var serviceNames []string

	appFiles, err := LoadAppFiles("")
	if err != nil {
		return serviceNames, err
	}

	app, err := GetApp(appFiles, appName)
	if err != nil {
		return serviceNames, err
	}

	composeFiles, err := GetAppComposeFiles(app.Recipe, app.Env)
	if err != nil {
		return serviceNames, err
	}

	opts := stack.Deploy{Composefiles: composeFiles}
	compose, err := GetAppComposeConfig(app.Recipe, opts, app.Env)
	if err != nil {
		return serviceNames, err
	}

	for _, service := range compose.Services {
		serviceNames = append(serviceNames, service.Name)
	}

	return serviceNames, nil
}

// GetAppNames retrieves a list of app names.
func GetAppNames() ([]string, error) {
	var appNames []string

	appFiles, err := LoadAppFiles("")
	if err != nil {
		return appNames, err
	}

	apps, err := GetApps(appFiles)
	if err != nil {
		return appNames, err
	}

	for _, app := range apps {
		appNames = append(appNames, app.Name)
	}

	return appNames, nil
}

// TemplateAppEnvSample copies the example env file for the app into the users env files
func TemplateAppEnvSample(recipeName, appName, server, domain string) error {
	envSamplePath := path.Join(RECIPES_DIR, recipeName, ".env.sample")
	envSample, err := ioutil.ReadFile(envSamplePath)
	if err != nil {
		return err
	}

	appEnvPath := path.Join(ABRA_DIR, "servers", server, fmt.Sprintf("%s.env", appName))
	if _, err := os.Stat(appEnvPath); os.IsExist(err) {
		return fmt.Errorf("%s already exists?", appEnvPath)
	}

	err = ioutil.WriteFile(appEnvPath, envSample, 0664)
	if err != nil {
		return err
	}

	file, err := os.OpenFile(appEnvPath, os.O_RDWR, 0664)
	if err != nil {
		return err
	}
	defer file.Close()

	tpl, err := template.ParseFiles(appEnvPath)
	if err != nil {
		return err
	}

	type templateVars struct {
		Name   string
		Domain string
	}

	tvars := templateVars{Name: recipeName, Domain: domain}
	if err := tpl.Execute(file, tvars); err != nil {
		return err
	}

	logrus.Debugf("copied & templated %s to %s", envSamplePath, appEnvPath)

	return nil
}

// SanitiseAppName makes a app name usable with Docker by replacing illegal characters
func SanitiseAppName(name string) string {
	return strings.ReplaceAll(name, ".", "_")
}

// GetAppStatuses queries servers to check the deployment status of given apps
func GetAppStatuses(appFiles AppFiles) (map[string]map[string]string, error) {
	statuses := make(map[string]map[string]string)

	var unique []string
	servers := make(map[string]struct{})
	for _, appFile := range appFiles {
		if _, ok := servers[appFile.Server]; !ok {
			servers[appFile.Server] = struct{}{}
			unique = append(unique, appFile.Server)
		}
	}

	bar := formatter.CreateProgressbar(len(servers), "querying remote servers...")
	ch := make(chan stack.StackStatus, len(servers))
	for server := range servers {
		go func(s string) {
			ch <- stack.GetAllDeployedServices(s)
			bar.Add(1)
		}(server)
	}

	for range servers {
		status := <-ch
		for _, service := range status.Services {
			result := make(map[string]string)
			name := service.Spec.Labels[convert.LabelNamespace]

			if _, ok := statuses[name]; !ok {
				result["status"] = "deployed"
			}

			labelKey := fmt.Sprintf("coop-cloud.%s.version", name)
			if version, ok := service.Spec.Labels[labelKey]; ok {
				result["version"] = version
			} else {
				continue
			}

			statuses[name] = result
		}
	}

	logrus.Debugf("retrieved app statuses: %s", statuses)

	return statuses, nil
}

// GetAppComposeFiles gets the list of compose files for an app which should be
// merged into a composetypes.Config while respecting the COMPOSE_FILE env var.
func GetAppComposeFiles(recipe string, appEnv AppEnv) ([]string, error) {
	var composeFiles []string

	if _, ok := appEnv["COMPOSE_FILE"]; !ok {
		logrus.Debug("no COMPOSE_FILE detected, loading compose.yml")
		path := fmt.Sprintf("%s/%s/compose.yml", RECIPES_DIR, recipe)
		composeFiles = append(composeFiles, path)
		return composeFiles, nil
	}

	composeFileEnvVar := appEnv["COMPOSE_FILE"]
	envVars := strings.Split(composeFileEnvVar, ":")
	logrus.Debugf("COMPOSE_FILE detected (%s), loading %s", composeFileEnvVar, strings.Join(envVars, ", "))
	for _, file := range strings.Split(composeFileEnvVar, ":") {
		path := fmt.Sprintf("%s/%s/%s", RECIPES_DIR, recipe, file)
		composeFiles = append(composeFiles, path)
	}

	logrus.Debugf("retrieved %s configs for %s", strings.Join(composeFiles, ", "), recipe)

	return composeFiles, nil
}

// GetAppComposeConfig retrieves a compose specification for a recipe. This
// specification is the result of a merge of all the compose.**.yml files in
// the recipe repository.
func GetAppComposeConfig(recipe string, opts stack.Deploy, appEnv AppEnv) (*composetypes.Config, error) {
	compose, err := loader.LoadComposefile(opts, appEnv)
	if err != nil {
		return &composetypes.Config{}, err
	}

	logrus.Debugf("retrieved %s for %s", compose.Filename, recipe)

	return compose, nil
}