// Command mailstore refuses any manifest but modules/mesh-mail claiming the mail-store seat (novox/hq ADR 0378
// §3, issue 800 part A): the operator's mail is read, searched and sent through this one seat, and a second
// claimant would be a second path to the same mail that ADR 0378 never accounted for.
//
//	go run . <catalogue root>
//
// Exits 1 on a finding.
package main

import (
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"
	"sort"
)

// MailStoreSeat is the seat only mesh-mail may claim.
const MailStoreSeat = "mail-store"

// MailStoreModule is the one module allowed to claim it.
const MailStoreModule = "mesh-mail"

// Finding is one manifest refused: a module other than mesh-mail claiming mail-store.
type Finding struct {
	Module string
}

// Check reads every manifest under root/modules and answers which ones it refuses.
func Check(root string) ([]Finding, error) {
	manifests, err := filepath.Glob(filepath.Join(root, "modules", "*", "module.json"))
	if err != nil {
		return nil, err
	}
	sort.Strings(manifests)
	var out []Finding
	for _, path := range manifests {
		raw, err := os.ReadFile(path)
		if err != nil {
			return nil, err
		}
		var m struct {
			Module string `json:"module"`
			Claims []struct {
				Name string `json:"name"`
			} `json:"claims"`
		}
		if err := json.Unmarshal(raw, &m); err != nil {
			return nil, fmt.Errorf("%s: %w", path, err)
		}
		if m.Module == MailStoreModule {
			continue
		}
		for _, c := range m.Claims {
			if c.Name == MailStoreSeat {
				out = append(out, Finding{Module: m.Module})
				break
			}
		}
	}
	return out, nil
}

func main() {
	root := "."
	if len(os.Args) > 1 {
		root = os.Args[1]
	}
	found, err := Check(root)
	if err != nil {
		fmt.Fprintln(os.Stderr, err)
		os.Exit(1)
	}
	for _, f := range found {
		fmt.Printf("%s claims the mail-store seat: only %s may (novox/hq ADR 0378 §3)\n", f.Module, MailStoreModule)
	}
	if len(found) > 0 {
		os.Exit(1)
	}
	fmt.Println("mail-store: claimed only by mesh-mail")
}