package main

// A module's act on the operator's warrant, recorded in the hand-act log (novox/hq ADR 0274, ADR 0259 §6).
//
//	mesh-controller hand-act warrant --asker <module> --ask <id>
//
// The verb `warranted` runs it. A module that asks the operator (an asker) acts on the warrant with its own grants;
// the controller's log is where a person's decisions are read back, so the module asks the controller to record
// it. **What is recorded is the router's word, never the caller's**: the controller reads the router's own record
// of that asker's ask — the bus lets only the router write it — and records who chose, through which channel, with
// which proofs, and which answer. The caller gives nothing but which ask: a word of its own, recorded first under
// the one id, would stand for every node's (the review of 2026-10-10). Recorded once per
// ask, under an id the ask decides, however many of the module's instances ask; an ask still open, ended without
// a choice, or another asker's is refused and nothing is written.

import (
	"context"
	"errors"
	"flag"
	"fmt"
	"regexp"

	"github.com/nats-io/nats.go"

	"git.novox.be/novox/mesh-sdk/go/asks"

	"github.com/novox/mesh-controller/internal/conditions"
	"github.com/novox/mesh-controller/internal/link"
)

var askerModule = regexp.MustCompile(`^[a-z0-9][a-z0-9-]{0,62}$`)

// warrantedID is the one entry an ask's warrant is recorded under.
func warrantedID(asker, ask string) string { return "warrant-" + asker + "-" + ask }

// warrantedAct is the entry for an asker's act on the warrant the router recorded for its ask (state, w), or why
// none is written.
func warrantedAct(asker, ask, caller, state string, w *asks.Warrant) (link.HandAct, error) {
	switch {
	case !askerModule.MatchString(asker):
		return link.HandAct{}, fmt.Errorf("%q is not a module's name", asker)
	case asker == askerName:
		return link.HandAct{}, errors.New("the controller records its own acts on a warrant as it performs them")
	case !asks.UsableID(ask):
		return link.HandAct{}, fmt.Errorf("%q is not an ask's id", ask)
	case state == "" || w == nil:
		return link.HandAct{}, fmt.Errorf("the router holds no closed record of %s's ask %s", asker, ask)
	case state == "open":
		return link.HandAct{}, fmt.Errorf("%s's ask %s is still open: nobody has answered it", asker, ask)
	case w.Asker != asker || w.Ask != ask:
		return link.HandAct{}, fmt.Errorf("the router's record is for %s's ask %s", w.Asker, w.Ask)
	case w.Outcome != asks.OutcomeChosen || w.By == nil:
		return link.HandAct{}, fmt.Errorf("%s's ask %s ended %s: no person chose, so there is no warrant to record", asker, ask, w.Outcome)
	case w.AskDigest == "":
		return link.HandAct{}, fmt.Errorf("the router's warrant for %s's ask %s names no ask digest", asker, ask)
	}
	return link.HandAct{ID: warrantedID(asker, ask), Verb: handActWarrant, Args: []string{fmt.Sprintf("the operator chose %s on %s's ask %s", w.Label, asker, ask)},
		Why: fmt.Sprintf("%s (ask %s of %s)", w.Says(), ask, asker), By: byWords(*w), Cause: conditions.CauseOperatorAnswer,
		Via: viaWords(*w), Ask: ask, Proofs: w.Proofs, RequestedBy: asker + ", recorded at the word of " + caller,
		Outcome: "chosen; what " + asker + " did with it is in its own record", At: w.At.UTC()}, nil
}

// readRouterRecord reads the router's record of one asker's ask: its state and warrant, or "" when there is none.
// The controller's grant reaches the JetStream API whole (`$JS.API.>`), so it reads any asker's record.
func readRouterRecord(ctx context.Context, conn *nats.Conn, bucket, asker, ask string) (string, *asks.Warrant, error) {
	state, _, w, err := readRouterEntry(ctx, conn, bucket, asker, ask)
	return state, w, err
}

func handActWarrantCommand(ctx context.Context, args []string) error {
	set := flag.NewFlagSet("hand-act warrant", flag.ContinueOnError)
	asker := set.String("asker", "", "the module that asked")
	ask := set.String("ask", "", "its ask's id")
	positionals, err := parseAround(set, args)
	if err != nil {
		return err
	}
	if *asker == "" || *ask == "" || len(positionals) > 0 {
		return errors.New("hand-act warrant --asker <module> --ask <id>: what is recorded is the router's record, and nothing else")
	}
	open, err := openStores(ctx)
	if err != nil {
		return err
	}
	defer open.Close()
	bucket, err := asksRecords(ctx, open.inventory)
	if err != nil {
		return err
	}
	if bucket == "" {
		return errors.New("no module declares the operator channel's records, so no warrant can be read")
	}
	return onTheBus(func(conn *nats.Conn) error {
		state, w, err := readRouterRecord(ctx, conn, bucket, *asker, *ask)
		if err != nil {
			return err
		}
		act, err := warrantedAct(*asker, *ask, link.Caller(), state, w)
		if err != nil {
			return fmt.Errorf("%w. Nothing was recorded", err)
		}
		written, err := link.RecordHandActOnce(ctx, conn, act)
		if err != nil {
			return fmt.Errorf("the warrant could not be recorded: %w", err)
		}
		if !written {
			fmt.Printf("already recorded as %s: %s\n", act.ID, act.Why)
			return nil
		}
		fmt.Printf("recorded as %s: %s, through %s\n", act.ID, act.Why, act.Via)
		return nil
	})
}