package store

import (
	"database/sql"
	"fmt"
	"sort"
	"strconv"
	"time"
)

// Operator actions (R-314 / R-279 / R-177, `09` §3 decision 185 — D1, design option A of
// documentation/audits/day-2026-10-08/design-R-314-279-177.md).
//
// The operator presses a button on the host page; a row is stored here and the box's intent generation
// is bumped, so its wait channel wakes; the report ACK lists every pending row as
// `operator_actions: [{id, action, arg}]`; the controller acts once per id and sends
// `operator_action_results: [{id, outcome, message}]` on its next report; the row is closed and stops
// being listed. The hub never connects into the box.
//
// THE LIST IS CLOSED, and the hub refuses an unknown action, job or argument BEFORE storing anything —
// the controller refuses them again on its side. Nothing on the list deletes data, starts a countdown or
// shortens one; `03` §4 asks for a signing key only to destroy or overwrite the only copy. The list is
// pinned on both sides (TestOperatorActions_ClosedList here, TestOpActions_ClosedList in the controller)
// so a new entry is an operator decision, not an edit.

const (
	OperatorActionOffsiteBackupNow = "offsite_backup_now"
	OperatorActionAbandonStop      = "abandon_stop"
	OperatorActionAbandonExtend    = "abandon_extend"
	OperatorActionRunJob           = "run_job"

	// Outcomes: the box's three, plus two the hub sets itself.
	OperatorActionDone      = "done"
	OperatorActionRefused   = "refused"
	OperatorActionFailed    = "failed"
	OperatorActionExpired   = "expired"   // the box did not answer within OperatorActionTTL
	OperatorActionCancelled = "cancelled" // the customer was RESET while it was pending

	OperatorActionExtendMinDays = 1
	OperatorActionExtendMaxDays = 30

	// OperatorActionTTL: a pending action the box has not answered in a day is closed as expired and
	// no longer listed — an off-site run pressed for a box that was off for a week must not start the
	// moment it comes back, unasked.
	OperatorActionTTL = 24 * time.Hour

	// operatorActionMessageMax bounds the box's message stored per row.
	operatorActionMessageMax = 500
	// operatorActionsListed caps how many pending rows one ACK carries.
	operatorActionsListed = 10
)

var operatorActionNames = []string{OperatorActionOffsiteBackupNow, OperatorActionAbandonStop, OperatorActionAbandonExtend, OperatorActionRunJob}

// operatorJobNames is the fixed set run_job may name — the controller's scheduler job names.
var operatorJobNames = []string{"fill-watch", "offsite-integrity", "offsite-proof", "disk-health-check"}

// OperatorActionNames returns the closed action list (sorted copy).
func OperatorActionNames() []string { return sortedStrings(operatorActionNames) }

// OperatorJobNames returns the fixed run_job set (sorted copy).
func OperatorJobNames() []string { return sortedStrings(operatorJobNames) }

func sortedStrings(in []string) []string {
	out := append([]string(nil), in...)
	sort.Strings(out)
	return out
}

func inList(list []string, v string) bool {
	for _, x := range list {
		if x == v {
			return true
		}
	}
	return false
}

// ValidateOperatorAction refuses anything outside the closed list. A nil error is the only way a row
// is stored.
func ValidateOperatorAction(action, arg string) error {
	switch action {
	case OperatorActionOffsiteBackupNow, OperatorActionAbandonStop:
		if arg != "" {
			return fmt.Errorf("%s takes no argument", action)
		}
	case OperatorActionAbandonExtend:
		d, err := strconv.Atoi(arg)
		if err != nil || d < OperatorActionExtendMinDays || d > OperatorActionExtendMaxDays {
			return fmt.Errorf("the number of days must be %d-%d", OperatorActionExtendMinDays, OperatorActionExtendMaxDays)
		}
	case OperatorActionRunJob:
		if !inList(operatorJobNames, arg) {
			return fmt.Errorf("unknown job %q", arg)
		}
	default:
		return fmt.Errorf("unknown action %q", action)
	}
	return nil
}

// OperatorActionDirective is ONE entry of the report ACK's operator_actions list — the wire type,
// named so scripts/wire_contract_gate.py can check it field by field against the controller's
// report.OperatorAction.
type OperatorActionDirective struct {
	ID     int64  `json:"id"`
	Action string `json:"action"`
	Arg    string `json:"arg,omitempty"`
}

// OperatorActionRow is one stored row, for the host page.
type OperatorActionRow struct {
	ID          int64
	CustomerID  string
	Action      string
	Arg         string
	RequestedAt time.Time
	RequestedBy string
	DoneAt      *time.Time
	Outcome     string
	Message     string
}

func (s *Store) migrateOperatorActions() error {
	_, err := s.db.Exec(`
		CREATE TABLE IF NOT EXISTS operator_actions (
			id           INTEGER PRIMARY KEY AUTOINCREMENT,
			customer_id  TEXT NOT NULL,
			action       TEXT NOT NULL,
			arg          TEXT NOT NULL DEFAULT '',
			requested_at DATETIME NOT NULL,
			requested_by TEXT NOT NULL DEFAULT '',
			done_at      DATETIME,
			outcome      TEXT NOT NULL DEFAULT '',
			message      TEXT NOT NULL DEFAULT ''
		);
		CREATE INDEX IF NOT EXISTS idx_operator_actions_customer ON operator_actions(customer_id, done_at);`)
	return err
}

// CreateOperatorAction validates against the closed list and stores a pending row. by names who
// pressed (the operator's channel and address — never a credential).
func (s *Store) CreateOperatorAction(customerID, action, arg, by string) (int64, error) {
	if customerID == "" {
		return 0, fmt.Errorf("operator action: empty customer id")
	}
	if err := ValidateOperatorAction(action, arg); err != nil {
		return 0, err
	}
	res, err := s.db.Exec(`INSERT INTO operator_actions (customer_id, action, arg, requested_at, requested_by)
		VALUES (?, ?, ?, ?, ?)`, customerID, action, arg, time.Now().UTC(), by)
	if err != nil {
		return 0, err
	}
	return res.LastInsertId()
}

// PendingOperatorActions returns what the next ACK lists for this customer, oldest first. Rows older
// than OperatorActionTTL are closed as expired first and are not listed.
func (s *Store) PendingOperatorActions(customerID string) ([]OperatorActionDirective, error) {
	now := time.Now().UTC()
	if _, err := s.db.Exec(`UPDATE operator_actions SET done_at = ?, outcome = ?, message = ?
		WHERE customer_id = ? AND done_at IS NULL AND requested_at < ?`,
		now, OperatorActionExpired, "the box did not answer within a day", customerID, now.Add(-OperatorActionTTL)); err != nil {
		return nil, err
	}
	rows, err := s.db.Query(`SELECT id, action, arg FROM operator_actions
		WHERE customer_id = ? AND done_at IS NULL ORDER BY id LIMIT ?`, customerID, operatorActionsListed)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	var out []OperatorActionDirective
	for rows.Next() {
		var d OperatorActionDirective
		if err := rows.Scan(&d.ID, &d.Action, &d.Arg); err != nil {
			return nil, err
		}
		out = append(out, d)
	}
	return out, rows.Err()
}

// RecordOperatorActionResult closes a pending row with the box's result. It matches on BOTH the id and
// the reporting customer, so a result naming another customer's action changes nothing (recorded=false).
// An outcome outside the box's three is refused. Returns the closed row when recorded.
func (s *Store) RecordOperatorActionResult(customerID string, id int64, outcome, message string) (*OperatorActionRow, error) {
	switch outcome {
	case OperatorActionDone, OperatorActionRefused, OperatorActionFailed:
	default:
		return nil, fmt.Errorf("unknown outcome %q", outcome)
	}
	if r := []rune(message); len(r) > operatorActionMessageMax {
		message = string(r[:operatorActionMessageMax])
	}
	res, err := s.db.Exec(`UPDATE operator_actions SET done_at = ?, outcome = ?, message = ?
		WHERE id = ? AND customer_id = ? AND done_at IS NULL`, time.Now().UTC(), outcome, message, id, customerID)
	if err != nil {
		return nil, err
	}
	if n, _ := res.RowsAffected(); n == 0 {
		return nil, nil
	}
	return s.getOperatorAction(id)
}

func (s *Store) getOperatorAction(id int64) (*OperatorActionRow, error) {
	rows, err := s.db.Query(`SELECT id, customer_id, action, arg, requested_at, requested_by, done_at, outcome, message
		FROM operator_actions WHERE id = ?`, id)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	list, err := scanOperatorActions(rows)
	if err != nil || len(list) == 0 {
		return nil, err
	}
	return &list[0], nil
}

// ListOperatorActions returns the customer's newest rows (pending and closed), newest first.
func (s *Store) ListOperatorActions(customerID string, limit int) ([]OperatorActionRow, error) {
	rows, err := s.db.Query(`SELECT id, customer_id, action, arg, requested_at, requested_by, done_at, outcome, message
		FROM operator_actions WHERE customer_id = ? ORDER BY id DESC LIMIT ?`, customerID, limit)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	return scanOperatorActions(rows)
}

func scanOperatorActions(rows *sql.Rows) ([]OperatorActionRow, error) {
	var out []OperatorActionRow
	for rows.Next() {
		var r OperatorActionRow
		var done sql.NullTime
		if err := rows.Scan(&r.ID, &r.CustomerID, &r.Action, &r.Arg, &r.RequestedAt, &r.RequestedBy, &done, &r.Outcome, &r.Message); err != nil {
			return nil, err
		}
		if done.Valid {
			t := done.Time
			r.DoneAt = &t
		}
		out = append(out, r)
	}
	return out, rows.Err()
}