add: reimplement discord bot

4 files changed, 494 insertions, 3 deletions

diff --git a/internal/bot/bot.go b/internal/bot/bot.go
index 1c8182d..4fb8fc8 100644
--- a/internal/bot/bot.go
+++ b/internal/bot/bot.go
@@ -1,8 +1,208 @@
 package bot
 
-import "fmt"
+import (
+	"errors"
+	"fmt"
+	"log"
+	"os"
+	"os/signal"
+	"strings"
+	"syscall"
+	"time"
+
+	"github.com/bwmarrin/discordgo"
+
+	"github.com/hachem-wtf/benson/internal/config"
+	"github.com/hachem-wtf/benson/internal/modrinth"
+)
 
 func Run() error {
-	fmt.Println("benson bot — not yet implemented")
-	return nil
+	cfg, err := config.Load()
+	if err != nil {
+		if os.IsNotExist(err) {
+			return fmt.Errorf("no config found — run `benson setup` to create one")
+		}
+		return fmt.Errorf("failed to load %s: %w", config.Path(), err)
+	}
+
+	api, err := config.LoadAPI()
+	if err != nil {
+		if os.IsNotExist(err) {
+			return fmt.Errorf("no bot token found — run `benson setup` to create one")
+		}
+		return fmt.Errorf("failed to load %s: %w", config.APIPath(), err)
+	}
+	if api.Token == "" {
+		return errors.New("config/api.json: token is empty")
+	}
+	if cfg.ChannelID == "" {
+		return errors.New("config/config.json: channel_id is empty")
+	}
+
+	session, err := discordgo.New("Bot " + api.Token)
+	if err != nil {
+		return err
+	}
+	session.Identify.Intents = discordgo.IntentsGuilds | discordgo.IntentsGuildMessages
+
+	ready := make(chan struct{})
+	session.AddHandler(func(s *discordgo.Session, r *discordgo.Ready) {
+		log.Printf("[OK] Logged in as %s", r.User.String())
+		close(ready)
+	})
+
+	if err := session.Open(); err != nil {
+		return err
+	}
+	defer session.Close()
+
+	<-ready
+
+	client := modrinth.NewClient()
+	checkAndReport(session, cfg, client)
+
+	interval := time.Duration(cfg.CheckIntervalMinutes) * time.Minute
+	if interval <= 0 {
+		interval = time.Hour
+	}
+	ticker := time.NewTicker(interval)
+	defer ticker.Stop()
+
+	stop := make(chan os.Signal, 1)
+	signal.Notify(stop, os.Interrupt, syscall.SIGTERM)
+
+	log.Printf("checking every %s — press Ctrl+C to stop", interval)
+
+	for {
+		select {
+		case <-ticker.C:
+			checkAndReport(session, cfg, client)
+		case <-stop:
+			log.Println("shutting down")
+			return nil
+		}
+	}
+}
+
+type report struct {
+	noCompatible          []string
+	newlyCompatible       []string
+	stillCompatibleUpdate []string
+}
+
+func checkAndReport(session *discordgo.Session, cfg *config.Config, client *modrinth.Client) {
+	rep := checkMods(cfg, client)
+
+	embed := buildEmbed(cfg, rep)
+	if embed == nil {
+		return
+	}
+
+	if _, err := session.ChannelMessageSendEmbed(cfg.ChannelID, embed); err != nil {
+		log.Println("[Discord] failed to send update:", err)
+		return
+	}
+	log.Println("[Discord] update message sent.")
+}
+
+func checkMods(cfg *config.Config, client *modrinth.Client) report {
+	cache, err := config.LoadCache()
+	if err != nil {
+		log.Println("[Cache] failed to load:", err)
+		cache = config.Cache{}
+	}
+	newCache := config.Cache{}
+
+	var rep report
+	for _, slug := range cfg.ModrinthMods {
+		versions, err := client.GetVersions(slug)
+		if err != nil {
+			log.Printf("[Modrinth] failed for %s: %v", slug, err)
+			continue
+		}
+
+		latest := modrinth.LatestVersion(versions)
+		compatible := modrinth.CompatibleVersion(versions, cfg.MinecraftVersion, "")
+
+		cached := cache[slug]
+
+		state := config.ModState{}
+		if compatible != nil {
+			state.Compatible = compatible.ID
+		}
+		if latest != nil {
+			state.Latest = latest.ID
+		}
+		newCache[slug] = state
+
+		switch {
+		case compatible == nil:
+			rep.noCompatible = append(rep.noCompatible, slug)
+		case cached.Compatible == "":
+			rep.newlyCompatible = append(rep.newlyCompatible, slug)
+		case latest != nil && latest.ID != cached.Latest:
+			rep.stillCompatibleUpdate = append(rep.stillCompatibleUpdate, slug)
+		}
+	}
+
+	if err := config.SaveCache(newCache); err != nil {
+		log.Println("[Cache] failed to save:", err)
+	}
+	return rep
+}
+
+const (
+	colorGood = 0x22C55E // green — everything compatible
+	colorWarn = 0xEF4444 // red — something has no compatible build
+)
+
+func buildEmbed(cfg *config.Config, rep report) *discordgo.MessageEmbed {
+	if len(rep.noCompatible) == 0 && len(rep.newlyCompatible) == 0 && len(rep.stillCompatibleUpdate) == 0 {
+		return nil
+	}
+
+	color := colorGood
+	if len(rep.noCompatible) > 0 {
+		color = colorWarn
+	}
+
+	var fields []*discordgo.MessageEmbedField
+	if f := section("🎉  Now compatible", rep.newlyCompatible); f != nil {
+		fields = append(fields, f)
+	}
+	if f := section("🟢  Updated (still compatible)", rep.stillCompatibleUpdate); f != nil {
+		fields = append(fields, f)
+	}
+	if f := section("❌  No compatible version", rep.noCompatible); f != nil {
+		fields = append(fields, f)
+	}
+
+	return &discordgo.MessageEmbed{
+		Author: &discordgo.MessageEmbedAuthor{
+			Name: "Modrinth compatibility",
+		},
+		Description: fmt.Sprintf("Fabric · Minecraft `%s`", cfg.MinecraftVersion),
+		Color:       color,
+		Fields:      fields,
+		Timestamp:   time.Now().Format(time.RFC3339),
+		Footer: &discordgo.MessageEmbedFooter{
+			Text: fmt.Sprintf("Benson · tracking %d mods", len(cfg.ModrinthMods)),
+		},
+	}
+}
+
+func section(name string, slugs []string) *discordgo.MessageEmbedField {
+	if len(slugs) == 0 {
+		return nil
+	}
+
+	var b strings.Builder
+	for _, slug := range slugs {
+		fmt.Fprintf(&b, "[`%s`](https://modrinth.com/mod/%s)\n", slug, slug)
+	}
+
+	return &discordgo.MessageEmbedField{
+		Name:  name,
+		Value: strings.TrimRight(b.String(), "\n"),
+	}
 }
diff --git a/internal/cli/cli.go b/internal/cli/cli.go
index d019730..7e7705e 100644
--- a/internal/cli/cli.go
+++ b/internal/cli/cli.go
@@ -2,6 +2,7 @@ package cli
 
 import (
 	"fmt"
+	"os"
 	"strings"
 
 	"github.com/charmbracelet/bubbles/spinner"
@@ -41,6 +42,9 @@ type model struct {
 func Run(version string) error {
 	cfg, err := config.Load()
 	if err != nil {
+		if os.IsNotExist(err) {
+			return fmt.Errorf("no config found — run `benson setup` to create one")
+		}
 		return fmt.Errorf("failed to load %s: %w", config.Path(), err)
 	}
 
diff --git a/internal/config/cache.go b/internal/config/cache.go
new file mode 100644
index 0000000..825af7f
--- /dev/null
+++ b/internal/config/cache.go
@@ -0,0 +1,63 @@
+package config
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+)
+
+type API struct {
+	Token string `json:"token"`
+}
+
+func LoadAPI() (*API, error) {
+	data, err := os.ReadFile(APIPath())
+	if err != nil {
+		return nil, err
+	}
+
+	var a API
+	if err := json.Unmarshal(data, &a); err != nil {
+		return nil, err
+	}
+	return &a, nil
+}
+
+type ModState struct {
+	Compatible string `json:"compatible"`
+	Latest     string `json:"latest"`
+}
+
+type Cache map[string]ModState
+
+func CachePath() string {
+	return filepath.Join("cache", "mod_versions.json")
+}
+
+func LoadCache() (Cache, error) {
+	data, err := os.ReadFile(CachePath())
+	if err != nil {
+		if os.IsNotExist(err) {
+			return Cache{}, nil
+		}
+		return nil, err
+	}
+
+	cache := Cache{}
+	if err := json.Unmarshal(data, &cache); err != nil {
+		return nil, err
+	}
+	return cache, nil
+}
+
+func SaveCache(cache Cache) error {
+	if err := os.MkdirAll(filepath.Dir(CachePath()), 0o755); err != nil {
+		return err
+	}
+
+	data, err := json.MarshalIndent(cache, "", "  ")
+	if err != nil {
+		return err
+	}
+	return os.WriteFile(CachePath(), data, 0o644)
+}
diff --git a/internal/setup/setup.go b/internal/setup/setup.go
new file mode 100644
index 0000000..eafaaa0
--- /dev/null
+++ b/internal/setup/setup.go
@@ -0,0 +1,224 @@
+package setup
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+
+	"github.com/charmbracelet/huh"
+	"github.com/charmbracelet/lipgloss"
+
+	"github.com/hachem-wtf/benson/internal/config"
+)
+
+// Run is the server-manager wizard. It configures Minecraft/Fabric versions,
+// paths, merge hooks and mods — everything except the Discord bot.
+func Run() error {
+	cfg := loadConfig()
+
+	var (
+		mcVersion    = cfg.MinecraftVersion
+		fabricLoader = cfg.FabricLoaderVersion
+		loaderMeta   = cfg.LoaderMetaVersion
+		javaPath     = cfg.JavaPath
+		serverLoc    = cfg.ServerLocation
+		backupLoc    = cfg.BackupLocation
+		preCmd       = cfg.MergePreCommand
+		postCmd      = cfg.MergePostCommand
+		modsText     = strings.Join(cfg.ModrinthMods, "\n")
+		confirm      = true
+	)
+
+	form := huh.NewForm(
+		huh.NewGroup(
+			huh.NewNote().
+				Title("Benson setup").
+				Description("Configure the server manager.\nThe Discord bot is optional — run `benson setup bot` for that."),
+		),
+		huh.NewGroup(
+			huh.NewInput().Title("Minecraft version").Placeholder("1.21.10").Value(&mcVersion).Validate(required("Minecraft version")),
+			huh.NewInput().Title("Fabric loader version").Placeholder("0.17.3").Value(&fabricLoader).Validate(required("Fabric loader version")),
+			huh.NewInput().Title("Loader / installer version").Placeholder("1.1.0").Value(&loaderMeta).Validate(required("loader version")),
+			huh.NewInput().Title("Java path").Description("Leave blank to use 'java' from PATH").Value(&javaPath),
+		).Title("Minecraft / Fabric"),
+		huh.NewGroup(
+			huh.NewInput().Title("Server location").Description("Live server directory, merged into by 'merge'").Value(&serverLoc),
+			huh.NewInput().Title("Backup location").Description("Where server backups are written").Value(&backupLoc),
+			huh.NewInput().Title("Pre-merge command").Description("Optional shell command run before merging").Value(&preCmd),
+			huh.NewInput().Title("Post-merge command").Description("Optional shell command run after merging").Value(&postCmd),
+		).Title("Paths & hooks (optional)"),
+		huh.NewGroup(
+			huh.NewText().Title("Modrinth mods").Description("One mod slug per line").Lines(8).Value(&modsText),
+		).Title("Mods"),
+		huh.NewGroup(
+			huh.NewConfirm().Title("Write config/config.json?").Affirmative("Write").Negative("Cancel").Value(&confirm),
+		),
+	)
+
+	if done, err := runForm(form); err != nil || !done {
+		return err
+	}
+
+	cfg.MinecraftVersion = strings.TrimSpace(mcVersion)
+	cfg.FabricLoaderVersion = strings.TrimSpace(fabricLoader)
+	cfg.LoaderMetaVersion = strings.TrimSpace(loaderMeta)
+	cfg.JavaPath = strings.TrimSpace(javaPath)
+	cfg.ServerLocation = strings.TrimSpace(serverLoc)
+	cfg.BackupLocation = strings.TrimSpace(backupLoc)
+	cfg.MergePreCommand = strings.TrimSpace(preCmd)
+	cfg.MergePostCommand = strings.TrimSpace(postCmd)
+	cfg.ModrinthMods = parseMods(modsText)
+
+	if err := writeConfigFile(cfg); err != nil {
+		return err
+	}
+
+	fmt.Printf("\n  %s Wrote %s\n\n  Run `benson` for the CLI, or `benson setup bot` to set up the Discord bot.\n\n",
+		check(), config.Path())
+	return nil
+}
+
+// RunBot is the Discord-bot wizard. It configures the bot token, channel and
+// check interval, leaving the server-manager settings untouched.
+func RunBot() error {
+	cfg := loadConfig()
+	api := loadAPI()
+
+	interval := cfg.CheckIntervalMinutes
+	if interval <= 0 {
+		interval = 60
+	}
+
+	var (
+		token       = api.Token
+		channelID   = cfg.ChannelID
+		intervalStr = strconv.Itoa(interval)
+		confirm     = true
+	)
+
+	form := huh.NewForm(
+		huh.NewGroup(
+			huh.NewNote().
+				Title("Benson bot setup").
+				Description("Configure the Discord bot that posts Modrinth compatibility reports."),
+		),
+		huh.NewGroup(
+			huh.NewInput().Title("Discord bot token").Description("Developer Portal → Bot → Reset/Copy Token").Password(true).Value(&token).Validate(required("token")),
+			huh.NewInput().Title("Channel ID").Description("Channel where reports are posted").Value(&channelID).Validate(required("channel ID")),
+			huh.NewInput().Title("Check interval (minutes)").Value(&intervalStr).Validate(positiveInt),
+		).Title("Discord"),
+		huh.NewGroup(
+			huh.NewConfirm().Title("Write config/config.json and config/api.json?").Affirmative("Write").Negative("Cancel").Value(&confirm),
+		),
+	)
+
+	if done, err := runForm(form); err != nil || !done {
+		return err
+	}
+
+	minutes, _ := strconv.Atoi(strings.TrimSpace(intervalStr))
+	cfg.ChannelID = strings.TrimSpace(channelID)
+	cfg.CheckIntervalMinutes = minutes
+	api.Token = strings.TrimSpace(token)
+
+	if err := writeConfigFile(cfg); err != nil {
+		return err
+	}
+	if err := writeAPIFile(api); err != nil {
+		return err
+	}
+
+	fmt.Printf("\n  %s Wrote %s\n  %s Wrote %s\n\n  Run `benson bot` to start the bot.\n\n",
+		check(), config.Path(), check(), config.APIPath())
+	return nil
+}
+
+func loadConfig() *config.Config {
+	if cfg, err := config.Load(); err == nil {
+		return cfg
+	}
+	return &config.Config{}
+}
+
+func loadAPI() *config.API {
+	if api, err := config.LoadAPI(); err == nil {
+		return api
+	}
+	return &config.API{}
+}
+
+// runForm runs a themed form, reporting whether the user confirmed the write.
+func runForm(form *huh.Form) (bool, error) {
+	if err := form.WithTheme(emberTheme()).Run(); err != nil {
+		if errors.Is(err, huh.ErrUserAborted) {
+			fmt.Println("Setup cancelled.")
+			return false, nil
+		}
+		return false, err
+	}
+	return true, nil
+}
+
+func required(label string) func(string) error {
+	return func(s string) error {
+		if strings.TrimSpace(s) == "" {
+			return fmt.Errorf("%s is required", label)
+		}
+		return nil
+	}
+}
+
+func positiveInt(s string) error {
+	n, err := strconv.Atoi(strings.TrimSpace(s))
+	if err != nil || n <= 0 {
+		return errors.New("must be a positive number")
+	}
+	return nil
+}
+
+func parseMods(text string) []string {
+	mods := []string{}
+	for _, line := range strings.Split(text, "\n") {
+		if slug := strings.TrimSpace(line); slug != "" {
+			mods = append(mods, slug)
+		}
+	}
+	return mods
+}
+
+func check() string {
+	return lipgloss.NewStyle().Foreground(lipgloss.Color("#22C55E")).Render("✓")
+}
+
+func emberTheme() *huh.Theme {
+	theme := huh.ThemeCharm()
+	ember := lipgloss.Color("#F97316")
+	theme.Focused.Title = theme.Focused.Title.Foreground(ember).Bold(true)
+	theme.Focused.Base = theme.Focused.Base.BorderForeground(ember)
+	return theme
+}
+
+func writeConfigFile(cfg *config.Config) error {
+	if err := os.MkdirAll(config.Dir, 0o755); err != nil {
+		return err
+	}
+	data, err := json.MarshalIndent(cfg, "", "  ")
+	if err != nil {
+		return err
+	}
+	return os.WriteFile(config.Path(), append(data, '\n'), 0o644)
+}
+
+func writeAPIFile(api *config.API) error {
+	if err := os.MkdirAll(config.Dir, 0o755); err != nil {
+		return err
+	}
+	data, err := json.MarshalIndent(api, "", "  ")
+	if err != nil {
+		return err
+	}
+	return os.WriteFile(config.APIPath(), append(data, '\n'), 0o600)
+}