package orgsettings

import (
	"context"

	"github.com/jackc/pgx/v5"

	"github.com/missionworkforce/missionmatch/internal/platform/security"
	"github.com/missionworkforce/missionmatch/internal/platform/tenant"
)

// FIELD SENSITIVITY, RESOLVED FOR THE CALLER, AND THE ONE PLACE IT IS ENFORCED.
//
// security.CanSeeField is the pure decision. This is the thing that actually asks it: it reads the
// organization's configured sensitivity, reads the caller's role from the validated session, and hands back
// three plain booleans that a response assembler can act on without knowing anything about roles or settings.
//
// IT EXISTS BECAUSE THE SETTING WAS DECORATIVE. CanSeeField had exactly one caller, GET /org/policy, which
// REPORTS the answers so an interface can hide a column. Nothing consulted it on a data path, so every
// candidate search returned every email address and every placement returned its margin, to every role, no
// matter what the owner had configured. An access control that only exists in the browser is not an access
// control: the answer was one curl away, and the settings screen was making a promise the API did not keep.
//
// ONE RESOLVER RATHER THAN ONE PER MODULE, deliberately. Contacts live in matching and rates live in
// recruiting, and two implementations of the same rule are two chances to get it different. This is the
// seam both call.

// Policy is what THIS caller may see, already decided. It carries no configuration: a consumer needs the
// answer, not the setting, and handing round the setting invites somebody to re derive the answer badly.
type Policy struct {
	CanSeeRates    bool
	CanSeeMargins  bool
	CanSeeContacts bool
}

// Unrestricted reports that nothing needs hiding, so a caller can skip a redaction walk entirely on the
// common path where an owner or an admin is reading.
func (p Policy) Unrestricted() bool { return p.CanSeeRates && p.CanSeeMargins && p.CanSeeContacts }

// ResolvePolicyTx resolves the caller's policy inside an existing tenant transaction.
//
// A NIL STORE RESOLVES TO THE SHIPPED DEFAULTS, not to permit everything and not to deny everything. Permit
// would reintroduce the hole this file closes. Deny would black out rates and contacts on a node that simply
// was not built with a settings store, which is a working configuration and must not become an empty product.
// The defaults are the same values the migration writes, so a node without a store behaves like a freshly
// provisioned organization, which is the only answer that is both safe and true.
//
// AN UNREADABLE SETTINGS ROW ALSO FALLS TO THE DEFAULTS rather than returning an error, and that is the
// deliberate choice: this is called from inside response assembly, where an error would turn a transient
// database hiccup into a failed page load. Falling to defaults degrades toward the restrictive side, which is
// the direction a failure in an access control is allowed to go.
func (s *Store) ResolvePolicyTx(ctx context.Context, tx pgx.Tx) Policy {
	st := Defaults()
	if s != nil {
		if loaded, err := s.LoadTx(ctx, tx); err == nil {
			st = loaded
		}
	}
	return policyFor(ctx, st)
}

// ResolvePolicy resolves the caller's policy in its own tenant transaction, for a caller that does not
// already hold one.
func (s *Store) ResolvePolicy(ctx context.Context) Policy {
	st := Defaults()
	if s != nil {
		if loaded, err := s.Load(ctx); err == nil {
			st = loaded
		}
	}
	return policyFor(ctx, st)
}

// policyFor asks the pure decision three times against the caller's role.
//
// NO PRINCIPAL DENIES EVERYTHING. That path should be unreachable, because every route that reaches here is
// behind the session resolver, but "should be unreachable" is not a reason to widen. An unauthenticated
// caller who somehow arrives here sees a record with no rate, no margin and no contact details rather than
// one with all three.
func policyFor(ctx context.Context, st Settings) Policy {
	p, ok := tenant.UserFromContext(ctx)
	if !ok {
		return Policy{}
	}
	role := security.Role(p.Role)
	return Policy{
		CanSeeRates:    security.CanSeeField(role, st.RateVisibility),
		CanSeeMargins:  security.CanSeeField(role, st.MarginVisibility),
		CanSeeContacts: security.CanSeeField(role, st.ContactVisibility),
	}
}