// Package authd — sources.go: Source CRUD for M13b W2.
//
// Sources are the *runtime* ingest-side counterpart of tenants.
// Each (company_id, id) row represents a single source that can
// POST events into ingestd. M13b W2 turns the existing
// public.sources table (created in migration 003) into a
// fully-managed resource in the admin UI.
//
// Schema (post-migration 011):
//   id                   TEXT
//   company_id           TEXT FK -> public.companies(id)
//   name                 TEXT
//   type                 TEXT (http | mqtt | ws | grpc)
//   rate_limit_per_sec   INTEGER
//   allowed_targets      JSONB  (M13c routing UI will edit; W2 read-only)
//   match_expr           JSONB  (M13c routing UI will edit; W2 read-only)
//   status               TEXT   (active | suspended)
//   hmac_secret_hash     TEXT   (bcrypt; returned only on create/rotate)
//   api_key_hash         TEXT   (bcrypt; returned only on create/rotate)
//   mtls_required        BOOLEAN (M14 reads; W2 just stores)
//   description          TEXT
//   created_at           TIMESTAMPTZ
//
// Bridge to auth.tenants:
//   auth.tenants.id is a UUID; public.sources.company_id is a
//   TEXT FK to public.companies.id (also TEXT). The two schemas
//   predate each other and were never formally linked. The
//   convention this code enforces: public.companies.id ==
//   auth.tenants.id::text. CreateSource uses ON CONFLICT
//   DO NOTHING to ensure a public.companies row exists before
//   the FK is hit, so creating a source for an auth tenant
//   without a corresponding public.companies row is a no-op
//   (idempotent) rather than an error.
//
// Threading: safe for concurrent use (pgx pool is goroutine-safe).
package authd

import (
	"context"
	"crypto/rand"
	"encoding/hex"
	"encoding/json"

	"golang.org/x/crypto/bcrypt"
	"errors"
	"fmt"
	"strings"
	"time"

	"github.com/jackc/pgx/v5"
	"github.com/jackc/pgx/v5/pgconn"
)

// Source is the wire shape returned to handlers / JSON callers.
// Secrets are NEVER included — only the booleans flagging their
// presence (`hmac_set`, `api_key_set`). Plaintext values live
// in the one-time SecretsPayload returned by CreateSource and
// RotateSecrets.
type Source struct {
	ID              string          `json:"id"`
	CompanyID       string          `json:"company_id"`
	Name            string          `json:"name"`
	Type            string          `json:"type"`
	RateLimitPerSec int             `json:"rate_limit_per_sec"`
	AllowedTargets  json.RawMessage `json:"allowed_targets"`
	MatchExpr       json.RawMessage `json:"match_expr"`
	Status          string          `json:"status"`
	MTLSRequired    bool            `json:"mtls_required"`
	Description     string          `json:"description,omitempty"`
	HMACSet         bool            `json:"hmac_set"`
	APIKeySet       bool            `json:"api_key_set"`
	CreatedAt       time.Time       `json:"created_at"`
}

// SecretsPayload is the one-time plaintext payload returned at
// create and rotate time. The UI shows it in a modal that
// requires the operator to confirm "I have saved these before
// continuing." After that, the values are gone from the server
// and the modal can never re-display them.
type SecretsPayload struct {
	HMACSecret string `json:"hmac_secret"`
	APIKey     string `json:"api_key"`
}

// ErrSourceNotFound is returned when (company_id, id) doesn't exist.
var ErrSourceNotFound = errors.New("authd: source not found")

// ErrSourceIDTaken is returned when CreateSource sees a
// duplicate (company_id, id) for a tenant that already has it.
var ErrSourceIDTaken = errors.New("authd: source id already in use")

// ErrSourceInvalid is returned when input validation fails.
var ErrSourceInvalid = errors.New("authd: source input invalid")

// validSourceTypes is the whitelist of `type` values. Mirrors
// the schema default comment in 003.
var validSourceTypes = map[string]struct{}{
	"http": {},
	"mqtt": {},
	"ws":   {},
	"grpc": {},
}

// SourceFilter controls ListSources. Empty fields mean "no filter".
type SourceFilter struct {
	Q            string // matches id OR name (ILIKE)
	Type         string // exact match
	Status       string // exact match
	Limit        int
	Offset       int
	CallerRole   string
	CallerTenant string // auth.tenants.id (UUID string)
}

// CreateSourceInput is the validated create payload. The optional
// HMAC + API key fields, if non-empty, are bcrypt-hashed by
// CreateSource. The plaintext is NEVER persisted; the caller
// receives it in the returned SecretsPayload.
type CreateSourceInput struct {
	ID              string
	Name            string
	Type            string
	RateLimitPerSec int
	AllowedTargets  json.RawMessage
	MatchExpr       json.RawMessage
	Description     string
	MTLSRequired    bool
	HMACSecret      string // optional; if non-empty, will be hashed
	APIKey          string // optional; if non-empty, will be hashed
}

// UpdateSourceInput is the PATCH payload. Pointer / non-nil
// fields mean "apply this." Nil raw-message means "leave the
// JSON column as-is." All fields are optional; an empty patch
// is a no-op.
type UpdateSourceInput struct {
	Name            *string
	Type            *string
	RateLimitPerSec *int
	Description     *string
	MTLSRequired    *bool
	AllowedTargets  json.RawMessage
	MatchExpr       json.RawMessage
}

// Validate runs the constraints the DB enforces, but earlier
// and with friendlier error messages for the UI.
func (in *CreateSourceInput) Validate() error {
	if !validSourceID(in.ID) {
		return fmt.Errorf("%w: id must match ^[a-z0-9][a-z0-9-]{0,62}[a-z0-9]$", ErrSourceInvalid)
	}
	if strings.TrimSpace(in.Name) == "" {
		return fmt.Errorf("%w: name is required", ErrSourceInvalid)
	}
	if len(in.Name) > 200 {
		return fmt.Errorf("%w: name must be \u2264 200 characters", ErrSourceInvalid)
	}
	if _, ok := validSourceTypes[in.Type]; !ok {
		return fmt.Errorf("%w: type must be http|mqtt|ws|grpc", ErrSourceInvalid)
	}
	if in.RateLimitPerSec < 1 || in.RateLimitPerSec > 1_000_000 {
		return fmt.Errorf("%w: rate_limit_per_sec must be 1..1000000", ErrSourceInvalid)
	}
	if len(in.Description) > 500 {
		return fmt.Errorf("%w: description must be \u2264 500 characters", ErrSourceInvalid)
	}
	// Empty raw messages are allowed; CreateSource defaults them to '[]' / '{}'.
	if len(in.AllowedTargets) > 0 && !json.Valid(in.AllowedTargets) {
		return fmt.Errorf("%w: allowed_targets must be valid JSON", ErrSourceInvalid)
	}
	if len(in.MatchExpr) > 0 && !json.Valid(in.MatchExpr) {
		return fmt.Errorf("%w: match_expr must be valid JSON", ErrSourceInvalid)
	}
	if in.HMACSecret != "" && !validSecretFormat(in.HMACSecret) {
		return fmt.Errorf("%w: hmac_secret, if provided, must be 32..128 [A-Za-z0-9_-] chars", ErrSourceInvalid)
	}
	if in.APIKey != "" && !validAPIKeyFormat(in.APIKey) {
		return fmt.Errorf("%w: api_key, if provided, must be 16..128 [A-Za-z0-9_-] chars", ErrSourceInvalid)
	}
	return nil
}

// Validate is the same for Update. We don't enforce presence
// of fields (PATCH can be empty), just per-field constraints.
func (in *UpdateSourceInput) Validate() error {
	if in.Name != nil {
		s := strings.TrimSpace(*in.Name)
		if s == "" {
			return fmt.Errorf("%w: name cannot be empty", ErrSourceInvalid)
		}
		if len(s) > 200 {
			return fmt.Errorf("%w: name must be \u2264 200 characters", ErrSourceInvalid)
		}
	}
	if in.Type != nil {
		if _, ok := validSourceTypes[*in.Type]; !ok {
			return fmt.Errorf("%w: type must be http|mqtt|ws|grpc", ErrSourceInvalid)
		}
	}
	if in.RateLimitPerSec != nil && (*in.RateLimitPerSec < 1 || *in.RateLimitPerSec > 1_000_000) {
		return fmt.Errorf("%w: rate_limit_per_sec must be 1..1000000", ErrSourceInvalid)
	}
	if in.Description != nil && len(*in.Description) > 500 {
		return fmt.Errorf("%w: description must be \u2264 500 characters", ErrSourceInvalid)
	}
	if in.AllowedTargets != nil && !json.Valid(in.AllowedTargets) {
		return fmt.Errorf("%w: allowed_targets must be valid JSON", ErrSourceInvalid)
	}
	if in.MatchExpr != nil && !json.Valid(in.MatchExpr) {
		return fmt.Errorf("%w: match_expr must be valid JSON", ErrSourceInvalid)
	}
	return nil
}

// ensurePublicCompanyRow makes sure public.companies has a row
// keyed by the auth.tenants.id (cast to text). This is the
// bridge between the M13a auth schema and the M0 data-plane
// schema. Idempotent; safe to call from CreateSource. The row
// carries just the minimum data: id, name (display_name), a
// default rate_limit, status='active'. Operators who want to
// manage the public.companies row's fields (rate_limit, etc.)
// can do so via the W1 tenant API; this code path only ensures
// the FK target exists.
func (s *Store) ensurePublicCompanyRow(ctx context.Context, tenantID, displayName string) error {
	if s.pool == nil {
		return errors.New("authd: no DB pool (test mode)")
	}
	const q = `
		INSERT INTO public.companies (id, name, status, rate_limit_per_sec)
		VALUES ($1::text, $2, 'active', 10000)
		ON CONFLICT (id) DO NOTHING
	`
	_, err := s.pool.Exec(ctx, q, tenantID, displayName)
	if err != nil {
		return fmt.Errorf("ensure public.companies row: %w", err)
	}
	return nil
}

// ListSources returns sources visible to the caller under the
// given filter, plus the total count. Scope: super_admin sees
// all tenants' sources; non-super_admin sees only the caller's
// tenant. CallerTenant is the auth.tenants.id (UUID string).
func (s *Store) ListSources(ctx context.Context, f SourceFilter) ([]Source, int, error) {
	if s.pool == nil {
		return nil, 0, errors.New("authd: no DB pool (test mode)")
	}
	if f.Limit <= 0 {
		f.Limit = 100
	}
	if f.Limit > 500 {
		f.Limit = 500
	}
	args := []any{}
	conds := []string{}

	if f.CallerRole != "super_admin" {
		if f.CallerTenant == "" {
			return []Source{}, 0, nil
		}
		// Bridge: public.sources.company_id (TEXT) = auth.tenants.id::text
		args = append(args, f.CallerTenant)
		conds = append(conds, fmt.Sprintf("company_id = $%d", len(args)))
	}
	if strings.TrimSpace(f.Type) != "" {
		args = append(args, f.Type)
		conds = append(conds, fmt.Sprintf("type = $%d", len(args)))
	}
	if strings.TrimSpace(f.Status) != "" {
		args = append(args, f.Status)
		conds = append(conds, fmt.Sprintf("status = $%d", len(args)))
	}
	if strings.TrimSpace(f.Q) != "" {
		args = append(args, "%"+strings.TrimSpace(f.Q)+"%")
		conds = append(conds, fmt.Sprintf("(id ILIKE $%d OR name ILIKE $%d)", len(args), len(args)))
	}
	where := ""
	if len(conds) > 0 {
		where = "WHERE " + strings.Join(conds, " AND ")
	}

	var total int
	if err := s.pool.QueryRow(ctx, "SELECT COUNT(*) FROM public.sources "+where, args...).Scan(&total); err != nil {
		return nil, 0, fmt.Errorf("count sources: %w", err)
	}

	args = append(args, f.Limit, f.Offset)
	q := fmt.Sprintf(`
		SELECT id, company_id, name, type, rate_limit_per_sec,
		       allowed_targets, match_expr, status, mtls_required,
		       COALESCE(description, ''),
		       (hmac_secret_hash IS NOT NULL),
		       (api_key_hash IS NOT NULL),
		       created_at
		FROM public.sources
		%s
		ORDER BY created_at DESC
		LIMIT $%d OFFSET $%d
	`, where, len(args)-1, len(args))
	rows, err := s.pool.Query(ctx, q, args...)
	if err != nil {
		return nil, 0, fmt.Errorf("list sources: %w", err)
	}
	defer rows.Close()
	out := make([]Source, 0, f.Limit)
	for rows.Next() {
		var src Source
		if err := rows.Scan(
			&src.ID, &src.CompanyID, &src.Name, &src.Type, &src.RateLimitPerSec,
			&src.AllowedTargets, &src.MatchExpr, &src.Status, &src.MTLSRequired,
			&src.Description, &src.HMACSet, &src.APIKeySet, &src.CreatedAt,
		); err != nil {
			return nil, 0, fmt.Errorf("scan source: %w", err)
		}
		out = append(out, src)
	}
	if err := rows.Err(); err != nil {
		return nil, 0, fmt.Errorf("rows: %w", err)
	}
	return out, total, nil
}

// GetSource fetches a single source by (company_id, id). Returns
// ErrSourceNotFound if missing. Caller is responsible for the
// per-id scope check (canAccessSource); this method is a
// straight DB lookup.
func (s *Store) GetSource(ctx context.Context, companyID, id string) (*Source, error) {
	if s.pool == nil {
		return nil, errors.New("authd: no DB pool (test mode)")
	}
	const q = `
		SELECT id, company_id, name, type, rate_limit_per_sec,
		       allowed_targets, match_expr, status, mtls_required,
		       COALESCE(description, ''),
		       (hmac_secret_hash IS NOT NULL),
		       (api_key_hash IS NOT NULL),
		       created_at
		FROM public.sources
		WHERE company_id = $1 AND id = $2
	`
	src := &Source{}
	err := s.pool.QueryRow(ctx, q, companyID, id).Scan(
		&src.ID, &src.CompanyID, &src.Name, &src.Type, &src.RateLimitPerSec,
		&src.AllowedTargets, &src.MatchExpr, &src.Status, &src.MTLSRequired,
		&src.Description, &src.HMACSet, &src.APIKeySet, &src.CreatedAt,
	)
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return nil, ErrSourceNotFound
		}
		return nil, fmt.Errorf("get source: %w", err)
	}
	return src, nil
}

// CreateSource inserts a new source and returns the row plus a
// one-time SecretsPayload. The bridge to public.companies is
// handled inside (ensurePublicCompanyRow). Audit log written.
//
// Behavior:
//   - Duplicate (company_id, id) returns ErrSourceIDTaken (409).
//   - If HMACSecret / APIKey are empty in the input, no hash is
//     stored; the resulting Source has hmac_set=false.
//   - If non-empty, they're bcrypt-hashed at cost 10 and the
//     plaintext is returned in SecretsPayload. The plaintext
//     is the ONLY time the UI can see it.
func (s *Store) CreateSource(
	ctx context.Context,
	tenantID, tenantDisplayName string,
	in CreateSourceInput,
	actorUserID, actorIP, actorUA string,
) (*Source, *SecretsPayload, error) {
	if s.pool == nil {
		return nil, nil, errors.New("authd: no DB pool (test mode)")
	}
	if err := in.Validate(); err != nil {
		return nil, nil, err
	}

	// Bridge: ensure public.companies has a row keyed by the
	// auth.tenants.id cast to text. This is the only place
	// authd writes to public.companies; everything else is
	// via the M13a auth.tenants API.
	if err := s.ensurePublicCompanyRow(ctx, tenantID, tenantDisplayName); err != nil {
		return nil, nil, err
	}

	// Default the JSONB columns if the caller didn't send
	// anything: '[]' for allowed_targets, '{}' for match_expr.
	allowedTargets := in.AllowedTargets
	if len(allowedTargets) == 0 {
		allowedTargets = json.RawMessage(`[]`)
	}
	matchExpr := in.MatchExpr
	if len(matchExpr) == 0 {
		matchExpr = json.RawMessage(`{}`)
	}

	// Hash the optional secrets. cost=10 mirrors the bootstrap
	// path; v1.1 will bump to 12 in prod.
	hmacHash, err := hashSecret(in.HMACSecret, "hmac")
	if err != nil {
		return nil, nil, err
	}
	apiKeyHash, err := hashSecret(in.APIKey, "api_key")
	if err != nil {
		return nil, nil, err
	}

	const q = `
		INSERT INTO public.sources
		    (company_id, id, name, type, rate_limit_per_sec,
		     allowed_targets, match_expr, status, mtls_required,
		     description, hmac_secret_hash, api_key_hash)
		VALUES
		    ($1::text, $2, $3, $4, $5,
		     $6, $7, 'active', $8,
		     NULLIF($9, ''), $10, $11)
		RETURNING id, company_id, name, type, rate_limit_per_sec,
		          allowed_targets, match_expr, status, mtls_required,
		          COALESCE(description, ''),
		          (hmac_secret_hash IS NOT NULL),
		          (api_key_hash IS NOT NULL),
		          created_at
	`
	src := &Source{}
	err = s.pool.QueryRow(ctx, q,
		tenantID, in.ID, in.Name, in.Type, in.RateLimitPerSec,
		allowedTargets, matchExpr, in.MTLSRequired,
		in.Description, nullableString(hmacHash), nullableString(apiKeyHash),
	).Scan(
		&src.ID, &src.CompanyID, &src.Name, &src.Type, &src.RateLimitPerSec,
		&src.AllowedTargets, &src.MatchExpr, &src.Status, &src.MTLSRequired,
		&src.Description, &src.HMACSet, &src.APIKeySet, &src.CreatedAt,
	)
	if err != nil {
		var pgErr *pgconn.PgError
		if errors.As(err, &pgErr) && pgErr.Code == "23505" {
			return nil, nil, ErrSourceIDTaken
		}
		return nil, nil, fmt.Errorf("create source: %w", err)
	}

	// Audit. The plaintext secrets are NOT included in the
	// audit payload — we only audit the fact that a source
	// was created, not the values.
	if err := s.WriteAudit(ctx, "source.create", actorUserID, actorIP, actorUA, src.CompanyID, src.ID, map[string]any{
		"name":              src.Name,
		"type":              src.Type,
		"rate_limit_per_sec": src.RateLimitPerSec,
		"mtls_required":     src.MTLSRequired,
		"hmac_set":          src.HMACSet,
		"api_key_set":       src.APIKeySet,
	}); err != nil {
		_ = err
	}

	// Build the secrets payload only if the caller actually
	// provided one. Empty input => no payload, so the UI knows
	// not to render the secrets modal.
	var payload *SecretsPayload
	if in.HMACSecret != "" || in.APIKey != "" {
		payload = &SecretsPayload{
			HMACSecret: in.HMACSecret,
			APIKey:     in.APIKey,
		}
	}
	return src, payload, nil
}

// UpdateSource applies a partial update and writes an audit row.
func (s *Store) UpdateSource(
	ctx context.Context,
	companyID, id string,
	in UpdateSourceInput,
	actorUserID, actorIP, actorUA string,
) (*Source, error) {
	if s.pool == nil {
		return nil, errors.New("authd: no DB pool (test mode)")
	}
	if err := in.Validate(); err != nil {
		return nil, err
	}
	sets := []string{}
	args := []any{companyID, id}
	if in.Name != nil {
		args = append(args, strings.TrimSpace(*in.Name))
		sets = append(sets, fmt.Sprintf("name = $%d", len(args)))
	}
	if in.Type != nil {
		args = append(args, *in.Type)
		sets = append(sets, fmt.Sprintf("type = $%d", len(args)))
	}
	if in.RateLimitPerSec != nil {
		args = append(args, *in.RateLimitPerSec)
		sets = append(sets, fmt.Sprintf("rate_limit_per_sec = $%d", len(args)))
	}
	if in.Description != nil {
		args = append(args, *in.Description)
		sets = append(sets, fmt.Sprintf("description = $%d", len(args)))
	}
	if in.MTLSRequired != nil {
		args = append(args, *in.MTLSRequired)
		sets = append(sets, fmt.Sprintf("mtls_required = $%d", len(args)))
	}
	if in.AllowedTargets != nil {
		args = append(args, in.AllowedTargets)
		sets = append(sets, fmt.Sprintf("allowed_targets = $%d", len(args)))
	}
	if in.MatchExpr != nil {
		args = append(args, in.MatchExpr)
		sets = append(sets, fmt.Sprintf("match_expr = $%d", len(args)))
	}
	if len(sets) == 0 {
		return s.GetSource(ctx, companyID, id)
	}
	q := fmt.Sprintf("UPDATE public.sources SET %s WHERE company_id = $1 AND id = $2", strings.Join(sets, ", "))
	tag, err := s.pool.Exec(ctx, q, args...)
	if err != nil {
		return nil, fmt.Errorf("update source: %w", err)
	}
	if tag.RowsAffected() == 0 {
		return nil, ErrSourceNotFound
	}

	payload := map[string]any{}
	if in.Name != nil {
		payload["name"] = *in.Name
	}
	if in.Type != nil {
		payload["type"] = *in.Type
	}
	if in.RateLimitPerSec != nil {
		payload["rate_limit_per_sec"] = *in.RateLimitPerSec
	}
	if in.Description != nil {
		payload["description"] = *in.Description
	}
	if in.MTLSRequired != nil {
		payload["mtls_required"] = *in.MTLSRequired
	}
	if in.AllowedTargets != nil {
		payload["allowed_targets_set"] = true
	}
	if in.MatchExpr != nil {
		payload["match_expr_set"] = true
	}
	if err := s.WriteAudit(ctx, "source.update", actorUserID, actorIP, actorUA, companyID, id, payload); err != nil {
		_ = err
	}
	return s.GetSource(ctx, companyID, id)
}

// SetSourceStatus flips status. Allowed transitions:
//   active    -> suspended
//   suspended -> active
// No archive state for sources (per the schema; only
// active|suspended).
func (s *Store) SetSourceStatus(
	ctx context.Context,
	companyID, id, newStatus string,
	actorUserID, actorIP, actorUA string,
) (*Source, error) {
	if s.pool == nil {
		return nil, errors.New("authd: no DB pool (test mode)")
	}
	switch newStatus {
	case "active", "suspended":
	default:
		return nil, fmt.Errorf("%w: status must be active|suspended", ErrSourceInvalid)
	}
	cur, err := s.GetSource(ctx, companyID, id)
	if err != nil {
		return nil, err
	}
	if cur.Status == newStatus {
		return cur, nil
	}
	if _, err := s.pool.Exec(ctx,
		"UPDATE public.sources SET status = $3 WHERE company_id = $1 AND id = $2",
		companyID, id, newStatus); err != nil {
		return nil, fmt.Errorf("set source status: %w", err)
	}
	if err := s.WriteAudit(ctx, "source.status", actorUserID, actorIP, actorUA, companyID, id, map[string]any{
		"from": cur.Status,
		"to":   newStatus,
	}); err != nil {
		_ = err
	}
	return s.GetSource(ctx, companyID, id)
}

// RotateSecrets generates a new HMAC secret + API key, hashes
// them, and returns the plaintext ONCE in SecretsPayload. The
// old secrets are immediately invalidated (overwritten in the
// DB). Use this when a source's credentials are suspected to
// have leaked.
func (s *Store) RotateSecrets(
	ctx context.Context,
	companyID, id string,
	actorUserID, actorIP, actorUA string,
) (*Source, *SecretsPayload, error) {
	if s.pool == nil {
		return nil, nil, errors.New("authd: no DB pool (test mode)")
	}
	// Confirm the source exists before we generate anything.
	// If it doesn't, we don't want to surface that a random
	// pair was generated and then discarded.
	cur, err := s.GetSource(ctx, companyID, id)
	if err != nil {
		return nil, nil, err
	}
	hmacPlain, err := generateSecret(32)
	if err != nil {
		return nil, nil, fmt.Errorf("generate hmac: %w", err)
	}
	apiPlain, err := generateAPIKey()
	if err != nil {
		return nil, nil, fmt.Errorf("generate api_key: %w", err)
	}
	hmacHash, err := hashSecret(hmacPlain, "hmac")
	if err != nil {
		return nil, nil, err
	}
	apiKeyHash, err := hashSecret(apiPlain, "api_key")
	if err != nil {
		return nil, nil, err
	}
	if _, err := s.pool.Exec(ctx,
		"UPDATE public.sources SET hmac_secret_hash = $3, api_key_hash = $4 WHERE company_id = $1 AND id = $2",
		companyID, id, hmacHash, apiKeyHash); err != nil {
		return nil, nil, fmt.Errorf("rotate secrets: %w", err)
	}
	if err := s.WriteAudit(ctx, "source.rotate_secrets", actorUserID, actorIP, actorUA, companyID, id, map[string]any{
		"hmac_rotated":   true,
		"api_key_rotated": true,
	}); err != nil {
		_ = err
	}
	updated, err := s.GetSource(ctx, companyID, id)
	if err != nil {
		return nil, nil, err
	}
	_ = cur
	return updated, &SecretsPayload{
		HMACSecret: hmacPlain,
		APIKey:     apiPlain,
	}, nil
}

// -------------------------------------------------------------------
// helpers
// -------------------------------------------------------------------

// validSourceID matches the same regex as auth.tenants.slug:
//   ^[a-z0-9][a-z0-9-]{0,62}[a-z0-9]$
func validSourceID(s string) bool {
	if len(s) < 2 || len(s) > 64 {
		return false
	}
	if !isAlnumOrDash(s[0]) || s[0] == '-' {
		return false
	}
	if !isAlnumOrDash(s[len(s)-1]) || s[len(s)-1] == '-' {
		return false
	}
	for i := 1; i < len(s)-1; i++ {
		if !isAlnumOrDash(s[i]) {
			return false
		}
	}
	return true
}

// validSecretFormat — HMAC secret: 32..128 [A-Za-z0-9_-] chars.
// Long enough to be cryptographically meaningful, short enough
// to paste into a config file by hand.
func validSecretFormat(s string) bool {
	if len(s) < 32 || len(s) > 128 {
		return false
	}
	for i := 0; i < len(s); i++ {
		c := s[i]
		if !((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') ||
			(c >= '0' && c <= '9') || c == '_' || c == '-') {
			return false
		}
	}
	return true
}

// validAPIKeyFormat — API key: 16..128 [A-Za-z0-9_-] chars.
func validAPIKeyFormat(s string) bool {
	if len(s) < 16 || len(s) > 128 {
		return false
	}
	for i := 0; i < len(s); i++ {
		c := s[i]
		if !((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') ||
			(c >= '0' && c <= '9') || c == '_' || c == '-') {
			return false
		}
	}
	return true
}

// generateSecret returns n random bytes hex-encoded.
func generateSecret(n int) (string, error) {
	buf := make([]byte, n)
	if _, err := rand.Read(buf); err != nil {
		return "", err
	}
	return hex.EncodeToString(buf), nil
}

// generateAPIKey returns 24 random bytes hex-encoded (48 chars).
// Hex is fine because the key never appears in URLs.
func generateAPIKey() (string, error) {
	return generateSecret(24)
}

// hashSecret bcrypts the plaintext at cost 10. Returns the
// empty string if the plaintext is empty (caller checks
// separately for "no secret was provided"). The `kind` arg is
// only used in the error path; the actual hash doesn't care.
func hashSecret(plain, kind string) (string, error) {
	if plain == "" {
		return "", nil
	}
	h, err := bcrypt.GenerateFromPassword([]byte(plain), 10)
	if err != nil {
		return "", fmt.Errorf("hash %s secret: %w", kind, err)
	}
	return string(h), nil
}

// nullableString returns nil for empty input, otherwise &s.
// Used to pass optional columns to pgx Exec / QueryRow.
func nullableString(s string) any {
	if s == "" {
		return nil
	}
	return s
}