// Command plexum-fabric-register binds a Plexum agent to a Fabric
// Center API key. Equivalent of openclaw's `fabric-register` script.
//
// Usage:
//
//	plexum-fabric-register --api-key fak_...
//	    # agent id from $AGENT_ID env (set by exec MCP tool)
//	plexum-fabric-register --agent-id alice --api-key fak_...
//
// Flags:
//   --api-key    Required. The Center-issued agent API key.
//   --agent-id   Optional when $AGENT_ID is set.
//   --center     Optional. Defaults to ${FABRIC_CENTER_API_BASE} or
//                http://localhost:7001/api.
//   --identity-file  Optional path to fabric-identity.json (default
//                ${PLEXUM_PROFILE_ROOT}/fabric-identity.json).
//
// Writes the (agent, api key, user id, email) tuple to identity file
// after validating the key against Center via /auth/agent/login.
package main

import (
	"context"
	"flag"
	"fmt"
	"os"
	"time"

	"git.hangman-lab.top/hzhang/Plexum-fabric-channel-plugin/internal/fabric"
	"git.hangman-lab.top/hzhang/Plexum-fabric-channel-plugin/internal/identity"
)

func main() {
	apiKey := flag.String("api-key", "", "Fabric Center API key (fak_...; required)")
	agentID := flag.String("agent-id", "", "agent id (defaults to $AGENT_ID)")
	centerBase := flag.String("center", "", "Center API base URL (default $FABRIC_CENTER_API_BASE or http://localhost:7001/api)")
	identityFile := flag.String("identity-file", "", "identity registry path (default $PLEXUM_PROFILE_ROOT/fabric-identity.json)")
	flag.Parse()

	if *apiKey == "" {
		fatalf("--api-key is required")
	}
	if *agentID == "" {
		*agentID = os.Getenv("AGENT_ID")
	}
	if *agentID == "" {
		fatalf("--agent-id required (or set AGENT_ID env)")
	}
	if *centerBase == "" {
		*centerBase = os.Getenv("FABRIC_CENTER_API_BASE")
	}
	if *centerBase == "" {
		*centerBase = "http://localhost:7001/api"
	}
	if *identityFile == "" {
		*identityFile = identity.DefaultPath()
	}

	ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
	defer cancel()

	client := fabric.New(*centerBase)
	sess, err := client.AgentLogin(ctx, *apiKey)
	if err != nil {
		fatalf("validate key against %s: %v", *centerBase, err)
	}

	reg, err := identity.Open(*identityFile)
	if err != nil {
		fatalf("open identity: %v", err)
	}
	reg.Set(*agentID, &identity.Entry{
		FabricAPIKey: *apiKey,
		FabricUserID: sess.User.ID,
		FabricEmail:  sess.User.Email,
		Enabled:      true,
	})
	if err := reg.Save(); err != nil {
		fatalf("save identity: %v", err)
	}

	fmt.Printf("registered agent %s as fabric user %s (%s); %d guilds\n",
		*agentID, sess.User.Email, sess.User.ID, len(sess.Guilds))
	fmt.Printf("identity file: %s\n", *identityFile)
	fmt.Println("restart the plexum gateway to pick up the new identity")
}

func fatalf(format string, args ...any) {
	fmt.Fprintf(os.Stderr, "plexum-fabric-register: "+format+"\n", args...)
	os.Exit(1)
}