package keeper

// msg_server.go implements the cover module's MsgServer (REQ-046, REQ-047,
// REQ-049, REQ-050, REQ-052, REQ-055, REQ-056, REQ-062, REQ-048, D-077,
// D-079, D-086, D-088, D-089, D-090). The MsgServer wraps the Keeper + the
// four expected-keeper shims (already on the Keeper: StandingKeeper,
// WatcherKeeper, BondKeeper, StillKeeper).
//
// Each method returns a (*Response, error). Handler state-machine ordering
// is enforced: ValidateBasic -> handler authz/gate -> state mutation ->
// ctx.EventManager().EmitEvent.
//
// P1 handler set:
//   - LaunchCoverPool: D-086 category phase check + D-077 Standing gate +
//     reserve floor + Watcher attestation; persists the CoverPool.
//   - RouteCoverFee: D-079 Anti-Crowding-Out firewall + category-tag match +
//     below-floor auto-pause + StillKeeper invocation; emits the routing
//     event.
//   - FileCoverCall: P1 scaffold — persists the CoverCall + emits an event;
//     P4 adds the Voucher adjudication + no-self-adjudication + slashing.
//
// P2 handler set:
//   - SignCoverCharter: D-090(1) Bill of Rights gate (ValidateBasic) +
//     idempotency + Watcher attestation; persists the CoverCharter.
//   - AmendCoverCharter: creates a CharterAmendment with Status=Proposed;
//     the 7-day cooling is enforced by CoolCharterAmendment /
//     RatifyCharterAmendment (keeper helpers).
//   - ElectPoolMason: loads/creates the PoolCouncil + adds the Mason (max
//     3 — a 4th is REJECTED).
//   - VoteCoverCall: loads the CoverCall + Watcher-observer-present check
//     for a CallVoteYes; persists the CoverCallVote.
//   - AmendPoolStandingGate: D-090(3) dual check (ValidateBasic + handler
//     re-check) + updates the pool's PoolStandingGate.
//   - EscalateReserveCeiling: 12-month age check + Watcher attestation +
//     sets the pool's reserve target to CoverReserveCeilingAnnualContribX.
//
// Nil-shim behavior (simtest wiring): a nil StandingKeeper skips the D-077
// gate (the handler still mutates state — the simtest documents the wiring
// contract); a nil WatcherKeeper skips the launch/charter/escalation
// attestation; a nil StillKeeper skips the auto-Still recording (the pool's
// PoolPaused flag is still set, just the Still event is not recorded in a
// still store); a nil BondKeeper is the P1 default (the P4 handler will
// reject a nil shim as a wiring error when the P4 MAB check is wired).

import (
	"fmt"

	sdk "github.com/cosmos/cosmos-sdk/types"

	"github.com/oy/openyield/x/cover/firewall"
	"github.com/oy/openyield/x/cover/types"
)

// msgServer is the concrete MsgServer implementation wrapping the Keeper.
type msgServer struct {
	Keeper
}

// NewMsgServerImpl returns the cover MsgServer for the provided Keeper.
func NewMsgServerImpl(k Keeper) types.MsgServer {
	return &msgServer{Keeper: k}
}

var _ types.MsgServer = msgServer{}

// unwrapCtx extracts the sdk.Context from the interface-typed ctx.
func unwrapCtx(ctx interface{}) sdk.Context {
	if c, ok := ctx.(sdk.Context); ok {
		return c
	}
	panic(fmt.Sprintf("cover: expected sdk.Context, got %T", ctx))
}

// gateForCategory returns the locked Standing gate floor for a Cover
// category (D-077). HealthMCS demands the Preferred gate (4.5); Travel +
// IncomePause use the Trusted gate (4.0) as the default. Other Phase2
// categories (none in P1) would also use the Trusted gate; the handler
// rejects out-of-phase categories BEFORE reaching this helper (the D-086
// phase check runs first), so this helper is only called for in-phase
// categories.
func gateForCategory(cat types.CoverCategory) float64 {
	if cat == types.CatHealthMCS {
		return types.CoverStandingGatePreferred
	}
	return types.CoverStandingGateTrusted
}

// bucketMeetsGate reports whether a Standing bucket string + score meet the
// locked gate floor (D-077). The bucket string is one of "New", "Trusted",
// "Preferred", "Top", "Slashed" (cross-doc to x/standing.StandingBucket).
// "Trusted" or higher ("Preferred", "Top") meets a Trusted gate; "Preferred"
// or higher ("Top") meets a Preferred gate. The score is a secondary check
// (defense in depth: the bucket is the primary gate, the score confirms).
// "New" or "Slashed" never meets either gate.
func bucketMeetsGate(bucket string, score float64, gate float64) bool {
	switch bucket {
	case "Top":
		return true
	case "Preferred":
		return gate <= types.CoverStandingGatePreferred && score >= gate
	case "Trusted":
		return gate <= types.CoverStandingGateTrusted && score >= gate
	}
	return false
}

// --- LaunchCoverPool ----------------------------------------------------------

// LaunchCoverPool launches a Cover Pool (REQ-046, REQ-047, REQ-049, D-077,
// D-086). The handler enforces:
//  1. ValidateBasic (stateless — floor check on ReserveAnnualContribRatio).
//  2. Idempotency: pool-id must not already exist.
//  3. D-086 category phase check: each category's phase must be in the
//     pool's FactoryAllowedPhases (P1 default = [Phase2] only — so only
//     Travel/HealthMCS/IncomePause allowed in P1; Phase3/Phase4 categories
//     REJECTED).
//  4. D-090(3) dual gate check: the Params.PoolStandingGate >= the protocol
//     minimum (CoverStandingGateTrusted) — a pool may tighten the gate but
//     never lower it.
//  5. D-077 Standing gate: for each category, query
//     StandingKeeper.GetStandingBucket(hostReachID, category). Compare the
//     returned bucket + score against the locked gate (Trusted for Travel/
//     IncomePause; Preferred for HealthMCS). A nil StandingKeeper skips
//     the gate check (simtest wiring).
//  6. Reserve floor re-check (REQ-047 defense in depth):
//     ReserveAnnualContribRatio >= CoverReserveFloorAnnualContribX.
//  7. Watcher attestation (REQ-046): WatcherKeeper.Attest(poolID, payload).
//     A nil WatcherKeeper skips (simtest).
//  8. Persist the CoverPool (PoolPaused = false, FactoryAllowedPhases +
//     PoolStandingGate from Params).
//
// On success an event is emitted.
func (s msgServer) LaunchCoverPool(ctx interface{}, msg *types.MsgLaunchCoverPool) (*types.MsgLaunchCoverPoolResponse, error) {
	if err := msg.ValidateBasic(); err != nil {
		return nil, err
	}
	sdkCtx := unwrapCtx(ctx)

	// Idempotency: pool-id must not already exist.
	if _, ok := s.Keeper.GetCoverPool(sdkCtx, msg.PoolID); ok {
		return nil, fmt.Errorf("cover: pool %q already exists", msg.PoolID)
	}

	// Load the Params (the effective Params: the override if set, else
	// DefaultParams). The D-086 simtest case (f) uses the override to
	// restrict FactoryAllowedPhases to [Phase2, Phase3] only and reject a
	// Phase4 launch. A future P2+ will load the Params from the params
	// store; for now the keeper holds the override.
	params := s.Keeper.Params()
	if err := params.Validate(); err != nil {
		return nil, fmt.Errorf("cover: params invalid: %w", err)
	}

	// D-086 category phase check: each category's phase must be in the
	// FactoryAllowedPhases (P1 default = [Phase2] only).
	allowed := make(map[types.CoverCategoryPhase]bool, len(params.FactoryAllowedPhases))
	for _, ph := range params.FactoryAllowedPhases {
		allowed[ph] = true
	}
	for _, cat := range msg.Categories {
		ph := types.CoverCategoryPhaseFor(cat)
		if ph == "" {
			return nil, fmt.Errorf("cover: unknown category %q (D-086 phase check)", cat)
		}
		if !allowed[ph] {
			return nil, fmt.Errorf("cover: category %q is phase %q, not in FactoryAllowedPhases %v (D-086: P1 allows %v only)", cat, ph, params.FactoryAllowedPhases, params.FactoryAllowedPhases)
		}
	}

	// D-077 Standing gate: for each category, query the host's Standing
	// bucket + score and compare against the locked gate. A nil
	// StandingKeeper skips the gate check (simtest wiring — documented).
	if s.Keeper.standingKeeper != nil {
		for _, cat := range msg.Categories {
			gate := gateForCategory(cat)
			bucket, score, err := s.Keeper.standingKeeper.GetStandingBucket(msg.HostReachID, string(cat))
			if err != nil {
				return nil, fmt.Errorf("cover: Standing lookup for host %q category %q: %w (D-077 gate)", msg.HostReachID, cat, err)
			}
			if !bucketMeetsGate(bucket, score, gate) {
				return nil, fmt.Errorf("cover: host %q Standing bucket %q score %.2f for category %q does not meet the locked gate %.2f (D-077)", msg.HostReachID, bucket, score, cat, gate)
			}
		}
	}

	// Reserve floor re-check (defense in depth — ValidateBasic already
	// checked this statelessly).
	if msg.ReserveAnnualContribRatio < types.CoverReserveFloorAnnualContribX {
		return nil, fmt.Errorf("cover: ReserveAnnualContribRatio %.2f < floor %.2f (REQ-047 handler re-check)", msg.ReserveAnnualContribRatio, types.CoverReserveFloorAnnualContribX)
	}

	// Watcher attestation (REQ-046). A nil WatcherKeeper skips (simtest).
	if s.Keeper.watcherKeeper != nil {
		payload := []byte(fmt.Sprintf("cover.launch:%s:%s:%v:%.2f", msg.PoolID, msg.HostReachID, msg.Categories, msg.ReserveAnnualContribRatio))
		if _, err := s.Keeper.watcherKeeper.Attest(msg.PoolID, payload); err != nil {
			return nil, fmt.Errorf("cover: Watcher attestation for pool %q: %w (REQ-046)", msg.PoolID, err)
		}
	}

	pool := types.CoverPool{
		PoolID:                    msg.PoolID,
		HostReachID:               msg.HostReachID,
		Categories:                msg.Categories,
		ReserveAnnualContribRatio: msg.ReserveAnnualContribRatio,
		ReserveAccount:            msg.ReserveAccount,
		PoolPaused:                false,
		CharterHash:               msg.CharterHash,
		FactoryAllowedPhases:      params.FactoryAllowedPhases,
		PoolStandingGate:          params.PoolStandingGate,
		CreatedAt:                 sdkCtx.BlockTime().Unix(),
	}
	s.Keeper.SetCoverPool(sdkCtx, pool)

	sdkCtx.EventManager().EmitEvent(sdk.NewEvent(
		"cover.pool_launched",
		sdk.NewAttribute("pool_id", msg.PoolID),
		sdk.NewAttribute("host_reach_id", msg.HostReachID),
		sdk.NewAttribute("reserve_annual_contrib_ratio", fmt.Sprintf("%.2f", msg.ReserveAnnualContribRatio)),
	))
	return &types.MsgLaunchCoverPoolResponse{}, nil
}

// --- RouteCoverFee ------------------------------------------------------------

// RouteCoverFee routes a Cover-Fee into a pool's reserve (REQ-050, D-079
// firewall, REQ-047 below-floor auto-pause). The handler enforces:
//  1. ValidateBasic (stateless).
//  2. Load the CoverPool. If not found, REJECT.
//  3. Below-floor pause check (REQ-047): if pool.PoolPaused == true, REJECT
//     with "pool paused (below reserve floor)".
//  4. D-079 Anti-Crowding-Out firewall: call
//     firewall.CheckCoverFeeRouting(pool.ReserveAccount). If the firewall
//     rejects (the destination is NOT permitted — e.g. the pool's
//     ReserveAccount is the Root-Pool operating-expenses holder), REJECT.
//  5. Category-tag validation (REQ-050, FR-COVER-11): the CategoryTag must
//     match one of the Pool's Categories. Mismatch -> REJECT.
//  6. Reserve floor check (REQ-047): if pool.ReserveAnnualContribRatio <
//     floor, REJECT the routing AND set pool.PoolPaused = true (auto-pause)
//     AND invoke StillKeeper.Still(poolID, "below reserve floor") (D-089(1)
//     — nil StillKeeper skips). Persist the paused pool. Emit
//     cover.pool_below_floor.
//  7. Otherwise: emit cover.cover_fee_routed (the routing is the event; the
//     reserve balance update is a simtest-grade stub).
func (s msgServer) RouteCoverFee(ctx interface{}, msg *types.MsgRouteCoverFee) (*types.MsgRouteCoverFeeResponse, error) {
	if err := msg.ValidateBasic(); err != nil {
		return nil, err
	}
	sdkCtx := unwrapCtx(ctx)

	pool, ok := s.Keeper.GetCoverPool(sdkCtx, msg.PoolID)
	if !ok {
		return nil, fmt.Errorf("cover: pool %q not found (RouteCoverFee rejected)", msg.PoolID)
	}

	// Below-floor pause check: a paused pool rejects all routing.
	if pool.PoolPaused {
		return nil, fmt.Errorf("cover: pool %q paused (below reserve floor) — routing rejected", msg.PoolID)
	}

	// D-079 Anti-Crowding-Out firewall: the destination (the pool's
	// ReserveAccount) must be a permitted routing destination. The firewall
	// is the second-layer defense (the first layer is the handler's own
	// destination-match check — the destination IS pool.ReserveAccount by
	// construction; the firewall catches a pool misconfigured to route to
	// the Root-Pool operating-expenses holder).
	if err := firewall.CheckCoverFeeRouting(pool.ReserveAccount); err != nil {
		return nil, fmt.Errorf("cover: %w (pool %q ReserveAccount %q)", err, msg.PoolID, pool.ReserveAccount)
	}

	// Category-tag validation (REQ-050, FR-COVER-11): the CategoryTag must
	// match one of the Pool's Categories.
	tagMatched := false
	for _, cat := range pool.Categories {
		if string(cat) == msg.CategoryTag {
			tagMatched = true
			break
		}
	}
	if !tagMatched {
		return nil, fmt.Errorf("cover: CategoryTag %q does not match any of pool %q categories %v (REQ-050)", msg.CategoryTag, msg.PoolID, pool.Categories)
	}

	// Reserve floor check (REQ-047): if the pool's ReserveAnnualContribRatio
	// is below the floor, REJECT the routing AND auto-pause the pool AND
	// invoke StillKeeper.Still (D-089(1)). A nil StillKeeper skips the
	// Still recording (the pool's PoolPaused flag is still set).
	if pool.ReserveAnnualContribRatio < types.CoverReserveFloorAnnualContribX {
		pool.PoolPaused = true
		s.Keeper.SetCoverPool(sdkCtx, pool)
		if s.Keeper.stillKeeper != nil {
			if err := s.Keeper.stillKeeper.Still(msg.PoolID, "below reserve floor"); err != nil {
				return nil, fmt.Errorf("cover: Still invocation for pool %q (below reserve floor): %w (D-089(1))", msg.PoolID, err)
			}
		}
		sdkCtx.EventManager().EmitEvent(sdk.NewEvent(
			"cover.pool_below_floor",
			sdk.NewAttribute("pool_id", msg.PoolID),
			sdk.NewAttribute("reserve_annual_contrib_ratio", fmt.Sprintf("%.2f", pool.ReserveAnnualContribRatio)),
			sdk.NewAttribute("floor", fmt.Sprintf("%.2f", types.CoverReserveFloorAnnualContribX)),
		))
		return nil, fmt.Errorf("cover: pool %q below reserve floor (%.2f < %.2f) — routing rejected, pool auto-paused (REQ-047)", msg.PoolID, pool.ReserveAnnualContribRatio, types.CoverReserveFloorAnnualContribX)
	}

	// Success: the routing is the event (the reserve balance update is a
	// simtest-grade stub — P2 may add a CoverFeeRouting record).
	sdkCtx.EventManager().EmitEvent(sdk.NewEvent(
		"cover.cover_fee_routed",
		sdk.NewAttribute("pool_id", msg.PoolID),
		sdk.NewAttribute("category_tag", msg.CategoryTag),
		sdk.NewAttribute("grain_amount", fmt.Sprintf("%d", msg.GrainAmount)),
		sdk.NewAttribute("reserve_account", pool.ReserveAccount),
	))
	return &types.MsgRouteCoverFeeResponse{}, nil
}

// --- FileCoverCall ------------------------------------------------------------

// FileCoverCall files a Cover Call against a pool's category (REQ-055 P1
// scaffold — the Voucher adjudication lands in P4). The handler enforces:
//  1. ValidateBasic (stateless).
//  2. Load the CoverPool. If not found, REJECT.
//  3. The category must match one of the Pool's Categories.
//  4. Persist the CoverCall. Emit cover.cover_call_filed.
//
// P4 adds: the Voucher assignment + no-self-adjudication (the
// ClaimantReachID must not be the adjudicating Voucher) + the MAB misuse
// auto-Still (D-089(1) — a Voucher whose MAB is slashed triggers the
// StillKeeper).
func (s msgServer) FileCoverCall(ctx interface{}, msg *types.MsgFileCoverCall) (*types.MsgFileCoverCallResponse, error) {
	if err := msg.ValidateBasic(); err != nil {
		return nil, err
	}
	sdkCtx := unwrapCtx(ctx)

	pool, ok := s.Keeper.GetCoverPool(sdkCtx, msg.PoolID)
	if !ok {
		return nil, fmt.Errorf("cover: pool %q not found (FileCoverCall rejected)", msg.PoolID)
	}

	// The category must match one of the Pool's Categories.
	catMatched := false
	for _, cat := range pool.Categories {
		if cat == msg.Category {
			catMatched = true
			break
		}
	}
	if !catMatched {
		return nil, fmt.Errorf("cover: category %q does not match any of pool %q categories %v", msg.Category, msg.PoolID, pool.Categories)
	}

	call := types.CoverCall{
		CallID:          msg.CallID,
		PoolID:          msg.PoolID,
		ClaimantReachID: msg.ClaimantReachID,
		Category:        msg.Category,
		AmountGrain:     msg.AmountGrain,
		FiledAt:         sdkCtx.BlockHeight(),
	}
	s.Keeper.SetCoverCall(sdkCtx, call)

	sdkCtx.EventManager().EmitEvent(sdk.NewEvent(
		"cover.cover_call_filed",
		sdk.NewAttribute("call_id", msg.CallID),
		sdk.NewAttribute("pool_id", msg.PoolID),
		sdk.NewAttribute("claimant_reach_id", msg.ClaimantReachID),
		sdk.NewAttribute("category", string(msg.Category)),
		sdk.NewAttribute("amount_grain", fmt.Sprintf("%d", msg.AmountGrain)),
	))
	return &types.MsgFileCoverCallResponse{}, nil
}

// --- P2: SignCoverCharter -----------------------------------------------------

// SignCoverCharter signs a Cover-Charter for a Pool (REQ-052, REQ-056,
// D-090(1)). The handler enforces:
//  1. ValidateBasic (stateless — includes the D-090(1) Bill of Rights
//     gate: any WaivedRights element REJECTS the signing).
//  2. Idempotency: CharterID must not already exist.
//  3. The referenced Pool must exist (the charter binds to a pool).
//  4. WatcherKeeper.Attest on the charter witness hash (a nil WatcherKeeper
//     skips; an empty WatcherWitnessHash skips).
//  5. Persist the CoverCharter + link the pool's CharterRef.
//  6. Emit cover.charter_signed.
func (s msgServer) SignCoverCharter(ctx interface{}, msg *types.MsgSignCoverCharter) (*types.MsgSignCoverCharterResponse, error) {
	if err := msg.ValidateBasic(); err != nil {
		return nil, err
	}
	sdkCtx := unwrapCtx(ctx)

	// Idempotency: charter-id must not already exist.
	if _, ok := s.Keeper.GetCoverCharter(sdkCtx, msg.CharterID); ok {
		return nil, fmt.Errorf("cover: charter %q already exists", msg.CharterID)
	}

	// The referenced pool must exist (the charter binds to a pool).
	pool, ok := s.Keeper.GetCoverPool(sdkCtx, msg.PoolID)
	if !ok {
		return nil, fmt.Errorf("cover: pool %q not found (SignCoverCharter rejected)", msg.PoolID)
	}

	// Watcher attestation over the witness hash (REQ-052). A nil
	// WatcherKeeper skips; an empty WatcherWitnessHash skips (the charter
	// may be signed without a witness in simtest).
	if s.Keeper.watcherKeeper != nil && len(msg.WatcherWitnessHash) > 0 {
		if _, err := s.Keeper.watcherKeeper.Attest(msg.PoolID, msg.WatcherWitnessHash); err != nil {
			return nil, fmt.Errorf("cover: Watcher attestation for charter %q: %w (REQ-052)", msg.CharterID, err)
		}
	}

	charter := types.CoverCharter{
		CharterID:              msg.CharterID,
		PoolID:                 msg.PoolID,
		StatementOfBeliefsHash: msg.StatementOfBeliefsHash,
		DisputePath:            msg.DisputePath,
		Gate:                   msg.Gate,
		HoldingPeriodDays:      msg.HoldingPeriodDays,
		HostReachID:            msg.HostReachID,
		WatcherWitnessHash:     msg.WatcherWitnessHash,
		Amendments:             []types.CharterAmendment{},
		WaivedRights:           msg.WaivedRights,
	}
	s.Keeper.SetCoverCharter(sdkCtx, charter)

	// Link the pool's CharterRef.
	pool.CharterRef = msg.CharterID
	s.Keeper.SetCoverPool(sdkCtx, pool)

	sdkCtx.EventManager().EmitEvent(sdk.NewEvent(
		"cover.charter_signed",
		sdk.NewAttribute("charter_id", msg.CharterID),
		sdk.NewAttribute("pool_id", msg.PoolID),
		sdk.NewAttribute("host_reach_id", msg.HostReachID),
	))
	return &types.MsgSignCoverCharterResponse{}, nil
}

// --- P2: AmendCoverCharter ----------------------------------------------------

// AmendCoverCharter files a Charter amendment (REQ-052). The handler
// enforces:
//  1. ValidateBasic (stateless).
//  2. The referenced charter must exist.
//  3. Create a CharterAmendment with Status=AmendmentProposed,
//     ProposedAt=now. Persist the amendment + append to the charter's
//     Amendments slice.
//  4. Emit cover.charter_amend_proposed.
//
// The 7-day cooling is enforced by CoolCharterAmendment /
// RatifyCharterAmendment (keeper helpers) — a simtest time-advance or a
// separate handler transitions the amendment to Cooled then Ratified.
func (s msgServer) AmendCoverCharter(ctx interface{}, msg *types.MsgAmendCoverCharter) (*types.MsgAmendCoverCharterResponse, error) {
	if err := msg.ValidateBasic(); err != nil {
		return nil, err
	}
	sdkCtx := unwrapCtx(ctx)

	charter, ok := s.Keeper.GetCoverCharter(sdkCtx, msg.CharterID)
	if !ok {
		return nil, fmt.Errorf("cover: charter %q not found (AmendCoverCharter rejected)", msg.CharterID)
	}

	// Idempotency: amendment-id must not already exist.
	if _, ok := s.Keeper.GetCharterAmendment(sdkCtx, msg.AmendmentID); ok {
		return nil, fmt.Errorf("cover: amendment %q already exists", msg.AmendmentID)
	}

	amendment := types.CharterAmendment{
		AmendmentID: msg.AmendmentID,
		Description: msg.Description,
		Status:      types.AmendmentProposed,
		ProposedAt:  sdkCtx.BlockTime().Unix(),
	}
	s.Keeper.SetCharterAmendment(sdkCtx, amendment)

	// Append the amendment to the charter's Amendments slice + persist.
	charter.Amendments = append(charter.Amendments, amendment)
	s.Keeper.SetCoverCharter(sdkCtx, charter)

	sdkCtx.EventManager().EmitEvent(sdk.NewEvent(
		"cover.charter_amend_proposed",
		sdk.NewAttribute("charter_id", msg.CharterID),
		sdk.NewAttribute("amendment_id", msg.AmendmentID),
	))
	return &types.MsgAmendCoverCharterResponse{}, nil
}

// --- P2: ElectPoolMason -------------------------------------------------------

// ElectPoolMason elects a Mason to the Pool Council (REQ-062). The
// handler enforces:
//  1. ValidateBasic (stateless).
//  2. The referenced pool must exist.
//  3. Load or create the PoolCouncil. Add the MasonReachID to
//     ElectedMasonReachIDs (max PoolCouncilMaxMasons = 3 — a 4th is
//     REJECTED). Reject a duplicate MasonReachID (already elected).
//  4. Persist the PoolCouncil + link the pool's CouncilRef.
//  5. Emit cover.pool_mason_elected.
func (s msgServer) ElectPoolMason(ctx interface{}, msg *types.MsgElectPoolMason) (*types.MsgElectPoolMasonResponse, error) {
	if err := msg.ValidateBasic(); err != nil {
		return nil, err
	}
	sdkCtx := unwrapCtx(ctx)

	pool, ok := s.Keeper.GetCoverPool(sdkCtx, msg.PoolID)
	if !ok {
		return nil, fmt.Errorf("cover: pool %q not found (ElectPoolMason rejected)", msg.PoolID)
	}

	council, exists := s.Keeper.GetPoolCouncil(sdkCtx, msg.PoolID)
	if !exists {
		council = types.PoolCouncil{
			PoolID:               msg.PoolID,
			HostReachID:          pool.HostReachID,
			ElectedMasonReachIDs: [3]string{},
		}
	}

	// Reject a duplicate MasonReachID (already elected).
	for _, m := range council.ElectedMasonReachIDs {
		if m == msg.MasonReachID {
			return nil, fmt.Errorf("cover: mason %q already elected to pool %q council (REQ-062)", msg.MasonReachID, msg.PoolID)
		}
	}

	// Find the first empty slot; if all 3 are filled, REJECT (max
	// PoolCouncilMaxMasons).
	slotIdx := -1
	for i, m := range council.ElectedMasonReachIDs {
		if m == "" {
			slotIdx = i
			break
		}
	}
	if slotIdx == -1 {
		return nil, fmt.Errorf("cover: pool %q council already has %d masons (REQ-062 max %d)", msg.PoolID, types.PoolCouncilMaxMasons, types.PoolCouncilMaxMasons)
	}
	council.ElectedMasonReachIDs[slotIdx] = msg.MasonReachID
	s.Keeper.SetPoolCouncil(sdkCtx, council)

	// Link the pool's CouncilRef (the council is keyed by pool-id, so the
	// ref is the pool-id itself).
	pool.CouncilRef = msg.PoolID
	s.Keeper.SetCoverPool(sdkCtx, pool)

	sdkCtx.EventManager().EmitEvent(sdk.NewEvent(
		"cover.pool_mason_elected",
		sdk.NewAttribute("pool_id", msg.PoolID),
		sdk.NewAttribute("mason_reach_id", msg.MasonReachID),
		sdk.NewAttribute("slot", fmt.Sprintf("%d", slotIdx)),
	))
	return &types.MsgElectPoolMasonResponse{}, nil
}

// --- P2: VoteCoverCall --------------------------------------------------------

// VoteCoverCall votes on a Cover Call (REQ-062). The handler enforces:
//  1. ValidateBasic (stateless — includes the valid VoteOption check).
//  2. The referenced CoverCall must exist.
//  3. The Watcher-observer-present check: if VoteOption == CallVoteYes and
//     WatcherObserverPresent == false, REJECT (majority requires observer
//     present — REQ-062).
//  4. Idempotency: VoteID must not already exist.
//  5. Persist the CoverCallVote. Emit cover.cover_call_voted.
func (s msgServer) VoteCoverCall(ctx interface{}, msg *types.MsgVoteCoverCall) (*types.MsgVoteCoverCallResponse, error) {
	if err := msg.ValidateBasic(); err != nil {
		return nil, err
	}
	sdkCtx := unwrapCtx(ctx)

	// The referenced CoverCall must exist.
	if _, ok := s.Keeper.GetCoverCall(sdkCtx, msg.CallID); !ok {
		return nil, fmt.Errorf("cover: call %q not found (VoteCoverCall rejected)", msg.CallID)
	}

	// The Watcher-observer-present check (REQ-062): a CallVoteYes requires
	// the Watcher observer to be present. A CallVoteNo / CallVoteAbstain
	// does NOT require the observer (only an affirmative vote demands the
	// witness).
	if msg.VoteOption == types.CallVoteYes && !msg.WatcherObserverPresent {
		return nil, fmt.Errorf("cover: CallVoteYes on call %q requires Watcher observer present (REQ-062)", msg.CallID)
	}

	// Idempotency: vote-id must not already exist.
	if _, ok := s.Keeper.GetCoverCallVote(sdkCtx, msg.VoteID); ok {
		return nil, fmt.Errorf("cover: vote %q already exists", msg.VoteID)
	}

	vote := types.CoverCallVote{
		VoteID:                 msg.VoteID,
		CallID:                 msg.CallID,
		PoolID:                 msg.PoolID,
		VoterReachID:           msg.VoterReachID,
		VoteOption:             msg.VoteOption,
		WatcherObserverPresent: msg.WatcherObserverPresent,
		VotedAt:                sdkCtx.BlockTime().Unix(),
	}
	s.Keeper.SetCoverCallVote(sdkCtx, vote)

	sdkCtx.EventManager().EmitEvent(sdk.NewEvent(
		"cover.cover_call_voted",
		sdk.NewAttribute("vote_id", msg.VoteID),
		sdk.NewAttribute("call_id", msg.CallID),
		sdk.NewAttribute("pool_id", msg.PoolID),
		sdk.NewAttribute("voter_reach_id", msg.VoterReachID),
		sdk.NewAttribute("vote_option", string(msg.VoteOption)),
	))
	return &types.MsgVoteCoverCallResponse{}, nil
}

// --- P2: AmendPoolStandingGate ------------------------------------------------

// AmendPoolStandingGate amends a Pool's Standing gate (D-090(3)). The
// handler enforces:
//  1. ValidateBasic (stateless — includes the D-090(3) dual check:
//     NewGate >= CoverStandingGateTrusted).
//  2. The referenced pool must exist.
//  3. D-090(3) handler re-check (defense in depth): NewGate >=
//     CoverStandingGateTrusted. ValidateBasic already checked, but the
//     handler re-checks in case of a future Params-bypass.
//  4. Update the pool's PoolStandingGate. Persist.
//  5. Emit cover.pool_standing_gate_amended.
func (s msgServer) AmendPoolStandingGate(ctx interface{}, msg *types.MsgAmendPoolStandingGate) (*types.MsgAmendPoolStandingGateResponse, error) {
	if err := msg.ValidateBasic(); err != nil {
		return nil, err
	}
	sdkCtx := unwrapCtx(ctx)

	pool, ok := s.Keeper.GetCoverPool(sdkCtx, msg.PoolID)
	if !ok {
		return nil, fmt.Errorf("cover: pool %q not found (AmendPoolStandingGate rejected)", msg.PoolID)
	}

	// D-090(3) handler re-check (defense in depth — ValidateBasic already
	// checked, but the handler re-checks in case of a future Params-bypass).
	if msg.NewGate < types.CoverStandingGateTrusted {
		return nil, fmt.Errorf("cover: NewGate %.2f < CoverStandingGateTrusted %.2f (D-090(3) handler re-check: a pool may tighten the gate but never lower it)", msg.NewGate, types.CoverStandingGateTrusted)
	}

	pool.PoolStandingGate = msg.NewGate
	s.Keeper.SetCoverPool(sdkCtx, pool)

	sdkCtx.EventManager().EmitEvent(sdk.NewEvent(
		"cover.pool_standing_gate_amended",
		sdk.NewAttribute("pool_id", msg.PoolID),
		sdk.NewAttribute("new_gate", fmt.Sprintf("%.2f", msg.NewGate)),
	))
	return &types.MsgAmendPoolStandingGateResponse{}, nil
}

// --- P2: EscalateReserveCeiling -----------------------------------------------

// EscalateReserveCeiling escalates a Pool's reserve target to the
// CoverReserveCeilingAnnualContribX (REQ-048). The handler enforces:
//  1. ValidateBasic (stateless).
//  2. The referenced pool must exist.
//  3. 12-month age check: now - pool.CreatedAt >= ReserveCeilingAgeSeconds
//     (365 days). A fresh pool is REJECTED. NOTE: pool.CreatedAt is set to
//     sdkCtx.BlockHeight() at launch in P1; for the age check we use
//     BlockTime().Unix() - pool.CreatedAt where pool.CreatedAt is
//     interpreted as a unix timestamp (the simtest sets CreatedAt to a
//     unix timestamp to satisfy this check).
//  4. Set the pool's ReserveAnnualContribRatio to
//     CoverReserveCeilingAnnualContribX (2.5).
//  5. WatcherKeeper.Attest (a nil WatcherKeeper skips).
//  6. Persist the updated pool. Emit cover.reserve_ceiling_escalated.
func (s msgServer) EscalateReserveCeiling(ctx interface{}, msg *types.MsgEscalateReserveCeiling) (*types.MsgEscalateReserveCeilingResponse, error) {
	if err := msg.ValidateBasic(); err != nil {
		return nil, err
	}
	sdkCtx := unwrapCtx(ctx)

	pool, ok := s.Keeper.GetCoverPool(sdkCtx, msg.PoolID)
	if !ok {
		return nil, fmt.Errorf("cover: pool %q not found (EscalateReserveCeiling rejected)", msg.PoolID)
	}

	// 12-month age check (REQ-048): the pool must have >= 365 days of
	// operating history before the reserve target can be escalated to the
	// ceiling. pool.CreatedAt is interpreted as a unix timestamp (the
	// simtest sets it accordingly).
	now := sdkCtx.BlockTime().Unix()
	if now-pool.CreatedAt < types.ReserveCeilingAgeSeconds {
		return nil, fmt.Errorf("cover: pool %q age %d seconds < %d seconds (REQ-048: 12-month operating history required for reserve ceiling escalation)", msg.PoolID, now-pool.CreatedAt, types.ReserveCeilingAgeSeconds)
	}

	// Set the pool's reserve target to the ceiling.
	pool.ReserveAnnualContribRatio = types.CoverReserveCeilingAnnualContribX

	// Watcher attestation (REQ-048). A nil WatcherKeeper skips.
	if s.Keeper.watcherKeeper != nil {
		payload := []byte(fmt.Sprintf("cover.escalate:%s:%.2f", msg.PoolID, types.CoverReserveCeilingAnnualContribX))
		if _, err := s.Keeper.watcherKeeper.Attest(msg.PoolID, payload); err != nil {
			return nil, fmt.Errorf("cover: Watcher attestation for reserve ceiling escalation on pool %q: %w (REQ-048)", msg.PoolID, err)
		}
	}

	s.Keeper.SetCoverPool(sdkCtx, pool)

	sdkCtx.EventManager().EmitEvent(sdk.NewEvent(
		"cover.reserve_ceiling_escalated",
		sdk.NewAttribute("pool_id", msg.PoolID),
		sdk.NewAttribute("reserve_annual_contrib_ratio", fmt.Sprintf("%.2f", types.CoverReserveCeilingAnnualContribX)),
	))
	return &types.MsgEscalateReserveCeilingResponse{}, nil
}