package cli

import (
	"encoding/json"
	"fmt"
	"io/ioutil"
	"net/http"
	"os"
	"path"
	"sort"
	"strings"
	"text/template"
	"time"

	"coopcloud.tech/abra/config"

	"github.com/go-git/go-git/v5"
	"github.com/sirupsen/logrus"
	"github.com/urfave/cli/v2"
)

type Image struct {
	Image  string `json:"image"`
	Rating string `json:"rating"`
	Source string `json:"source"`
	URL    string `json:"url"`
}

type Feature struct {
	Backups     string `json:"backups"`
	Email       string `json:"email"`
	Healthcheck string `json:"healthcheck"`
	Image       Image  `json:"image"`
	Status      int    `json:"status"`
	Tests       string `json:"tests"`
}

type Tag = string
type Service = string
type ServiceMeta struct {
	Digest string `json:"digest"`
	Image  string `json:"image"`
	Tag    string `json:"tag"`
}

type App struct {
	Category      string                          `json:"category"`
	DefaultBranch string                          `json:"default_branch"`
	Description   string                          `json:"description"`
	Features      Feature                         `json:"features"`
	Icon          string                          `json:"icon"`
	Name          string                          `json:"name"`
	Repository    string                          `json:"repository"`
	Versions      map[Tag]map[Service]ServiceMeta `json:"versions"`
	Website       string                          `json:"website"`
}

type Name = string
type AppsCatalogue map[Name]App

func (a AppsCatalogue) Flatten() []App {
	apps := make([]App, 0, len(a))
	for name := range a {
		apps = append(apps, a[name])
	}
	return apps
}

type ByAppName []App

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

var httpClient = &http.Client{Timeout: 5 * time.Second}

var AppsCatalogueURL = "https://apps.coopcloud.tech"

func readJson(url string, target interface{}) error {
	res, err := httpClient.Get(url)
	if err != nil {
		return err
	}
	defer res.Body.Close()
	return json.NewDecoder(res.Body).Decode(target)
}

func AppsCatalogueFSIsLatest() (bool, error) {
	res, err := httpClient.Head(AppsCatalogueURL)
	if err != nil {
		return false, err
	}

	lastModified := res.Header["Last-Modified"][0]
	parsed, err := time.Parse(time.RFC1123, lastModified)
	if err != nil {
		return false, err
	}

	info, err := os.Stat(config.APPS_JSON)
	if err != nil {
		if os.IsNotExist(err) {
			return false, nil
		}
		return false, err
	}

	localModifiedTime := info.ModTime().Unix()
	remoteModifiedTime := parsed.Unix()

	if localModifiedTime < remoteModifiedTime {
		return false, nil
	}

	return true, nil
}

func ReadAppsCatalogue() (AppsCatalogue, error) {
	apps := make(AppsCatalogue)

	appsFSIsLatest, err := AppsCatalogueFSIsLatest()
	if err != nil {
		return nil, err
	}

	if !appsFSIsLatest {
		if err := ReadAppsCatalogueWeb(&apps); err != nil {
			return nil, err
		}
		return apps, nil
	}

	if err := ReadAppsCatalogueFS(&apps); err != nil {
		return nil, err
	}

	return apps, nil
}

func ReadAppsCatalogueFS(target interface{}) error {
	appsJsonFS, err := ioutil.ReadFile(config.APPS_JSON)
	if err != nil {
		return err
	}
	if err := json.Unmarshal(appsJsonFS, &target); err != nil {
		return err
	}
	return nil
}

func ReadAppsCatalogueWeb(target interface{}) error {
	if err := readJson(AppsCatalogueURL, &target); err != nil {
		return err
	}

	appsJson, err := json.MarshalIndent(target, "", "    ")
	if err != nil {
		return err
	}

	if err := ioutil.WriteFile(config.APPS_JSON, appsJson, 0644); err != nil {
		return err
	}

	return nil
}

var recipeListCommand = &cli.Command{
	Name:    "list",
	Aliases: []string{"ls"},
	Action: func(c *cli.Context) error {
		catalogue, err := ReadAppsCatalogue()
		if err != nil {
			logrus.Fatal(err.Error())
		}
		apps := catalogue.Flatten()
		sort.Sort(ByAppName(apps))
		tableCol := []string{"Name", "Category", "Status"}
		table := createTable(tableCol)
		for _, app := range apps {
			status := fmt.Sprintf("%v", app.Features.Status)
			tableRow := []string{app.Name, app.Category, status}
			table.Append(tableRow)
		}
		table.Render()
		return nil
	},
}

var recipeVersionCommand = &cli.Command{
	Name:      "versions",
	Usage:     "List available versions for <recipe>",
	ArgsUsage: "<recipe>",
	Action: func(c *cli.Context) error {
		recipe := c.Args().First()
		if recipe == "" {
			cli.ShowSubcommandHelp(c)
			return nil
		}

		apps, err := ReadAppsCatalogue()
		if err != nil {
			logrus.Fatal(err)
			return nil
		}

		if app, ok := apps[recipe]; ok {
			tableCol := []string{"Version", "Service", "Image", "Digest"}
			table := createTable(tableCol)
			for version := range app.Versions {
				for service := range app.Versions[version] {
					meta := app.Versions[version][service]
					table.Append([]string{version, service, meta.Image, meta.Digest})
				}
			}
			table.SetAutoMergeCells(true)
			table.Render()
			return nil
		}

		logrus.Fatalf("'%s' recipe doesn't exist?", recipe)
		return nil
	},
}

var recipeCreateCommand = &cli.Command{
	Name:      "create",
	Usage:     "Create a new recipe",
	ArgsUsage: "<recipe>",
	Action: func(c *cli.Context) error {
		recipe := c.Args().First()
		if recipe == "" {
			cli.ShowSubcommandHelp(c)
			return nil
		}

		directory := path.Join(config.APPS_DIR, recipe)
		if _, err := os.Stat(directory); !os.IsNotExist(err) {
			logrus.Fatalf("'%s' recipe directory already exists?", directory)
			return nil
		}

		url := fmt.Sprintf("%s/example.git", config.REPOS_BASE_URL)
		_, err := git.PlainClone(directory, false, &git.CloneOptions{URL: url})
		if err != nil {
			logrus.Fatal(err)
			return nil
		}

		gitRepo := path.Join(config.APPS_DIR, recipe, ".git")
		if err := os.RemoveAll(gitRepo); err != nil {
			logrus.Fatal(err)
			return nil
		}

		toParse := []string{
			path.Join(config.APPS_DIR, recipe, "README.md"),
			path.Join(config.APPS_DIR, recipe, ".env.sample"),
			path.Join(config.APPS_DIR, recipe, ".drone.yml"),
		}
		for _, path := range toParse {
			file, err := os.OpenFile(path, os.O_RDWR, 0755)
			if err != nil {
				logrus.Fatal(err)
				return nil
			}

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

			// TODO: ask for description and probably other things so that the
			// template repository is more "ready" to go than the current best-guess
			// mode of templating
			if err := tpl.Execute(file, struct {
				Name        string
				Description string
			}{recipe, "TODO"}); err != nil {
				logrus.Fatal(err)
				return nil
			}
		}

		fmt.Printf(
			"New recipe '%s' created in %s, happy hacking!",
			recipe, path.Join(config.APPS_DIR, recipe),
		)

		return nil
	},
}

var RecipeCommand = &cli.Command{
	Name:     "recipe",
	HideHelp: true,
	Subcommands: []*cli.Command{
		recipeListCommand,
		recipeVersionCommand,
		recipeCreateCommand,
	},
}