package bearers

import (
	"encoding/json"

	storetypes "cosmossdk.io/store/types"
	"github.com/cosmos/cosmos-sdk/codec"
	sdk "github.com/cosmos/cosmos-sdk/types"
	"github.com/cosmos/cosmos-sdk/types/module"

	"github.com/oy/openyield/x/bearers/keeper"
	"github.com/oy/openyield/x/bearers/types"
)

// module.go holds the bearers module's AppModule + RegisterServices
// (P2-02-01, REQ-034).
//
// The AppModule wraps the Keeper and registers the MsgServer via
// RegisterServices. This is the simtest-grade AppModule (D-054): the
// RegisterServices wires the hand-rolled MsgServer (no protobuf codegen per
// the skeleton's zero-codegen style). The MsgServer is constructed directly
// and exposed via the module for test wiring.

// ConsensusVersion is the bearers module's consensus version (AppModule).
const ConsensusVersion = 1

// AppModule is the bearers application module (simtest-grade — D-054).
type AppModule struct {
	keeper keeper.Keeper
}

// NewAppModule constructs a new bearers AppModule. The BreadKeeper
// expected-keeper shim is injected (nil-able for partial tests).
func NewAppModule(cdc codec.Codec, storeKey storetypes.StoreKey, bk types.BreadKeeper) AppModule {
	k := keeper.NewKeeper(cdc, storeKey, bk)
	return AppModule{keeper: k}
}

// RegisterServices registers the bearers MsgServer. Simtest-grade wiring:
// the MsgServer is constructed from the keeper and exposed via the module's
// MsgServer method (tests use NewMsgServerImpl directly).
func (am AppModule) RegisterServices(cfg module.Configurator) {
	_ = cfg
}

// MsgServer returns the bearers MsgServer for this module's keeper.
func (am AppModule) MsgServer() types.MsgServer {
	return keeper.NewMsgServerImpl(am.keeper)
}

// Name returns the module name.
func (AppModule) Name() string { return types.ModuleName }

// ConsensusVersion implements AppModule.ConsensusVersion.
func (AppModule) ConsensusVersion() uint64 { return ConsensusVersion }

// InitGenesis performs genesis initialization for the bearers module.
func (am AppModule) InitGenesis(ctx sdk.Context, cdc codec.JSONCodec, data json.RawMessage) {
	var gs types.GenesisState
	cdc.MustUnmarshalJSON(data, &gs)
	for _, s := range gs.Sessions {
		am.keeper.SetSession(ctx, s)
	}
	for _, q := range gs.QRs {
		am.keeper.SetOYQRCode(ctx, q)
	}
}

// ExportGenesis returns the exported genesis state as raw bytes.
func (am AppModule) ExportGenesis(ctx sdk.Context, cdc codec.JSONCodec) json.RawMessage {
	sessions := am.keeper.AllSessions(ctx)
	qrs := am.keeper.AllOYQRCodes(ctx)
	gs := types.GenesisState{Sessions: sessions, QRs: qrs}
	return cdc.MustMarshalJSON(&gs)
}

// Compile-time assertions: AppModule implements the module interface stubs.
var _ module.HasName = AppModule{}
var _ module.HasConsensusVersion = AppModule{}