package mint

import (
	"context"
	"encoding/json"
	"fmt"

	gwruntime "github.com/grpc-ecosystem/grpc-gateway/runtime"
	"google.golang.org/grpc"

	"cosmossdk.io/core/appmodule"
	"cosmossdk.io/x/mint/keeper"
	"cosmossdk.io/x/mint/simulation"
	"cosmossdk.io/x/mint/types"

	"github.com/cosmos/cosmos-sdk/client"
	"github.com/cosmos/cosmos-sdk/codec"
	cdctypes "github.com/cosmos/cosmos-sdk/codec/types"
	"github.com/cosmos/cosmos-sdk/types/module"
	simtypes "github.com/cosmos/cosmos-sdk/types/simulation"
)

// ConsensusVersion defines the current x/mint module consensus version.
const ConsensusVersion = 2

var (
	_ module.HasName               = AppModule{}
	_ module.HasAminoCodec         = AppModule{}
	_ module.HasGRPCGateway        = AppModule{}
	_ module.HasRegisterInterfaces = AppModule{}
	_ module.AppModuleSimulation   = AppModule{}
	_ module.HasGenesis            = AppModule{}

	_ appmodule.AppModule       = AppModule{}
	_ appmodule.HasBeginBlocker = AppModule{}
	_ appmodule.HasServices     = AppModule{}
	_ appmodule.HasMigrations   = AppModule{}
)

// AppModule implements an application module for the mint module.
type AppModule struct {
	cdc        codec.Codec
	keeper     keeper.Keeper
	authKeeper types.AccountKeeper

	// inflationCalculator is used to calculate the inflation rate during BeginBlock.
	// If inflationCalculator is nil, the default inflation calculation logic is used.
	inflationCalculator types.InflationCalculationFn
}

// NewAppModule creates a new AppModule object.
// If the InflationCalculationFn argument is nil, then the SDK's default inflation function will be used.
func NewAppModule(
	cdc codec.Codec,
	keeper keeper.Keeper,
	ak types.AccountKeeper,
	ic types.InflationCalculationFn,
) AppModule {
	if ic == nil {
		ic = types.DefaultInflationCalculationFn
	}

	return AppModule{
		cdc:                 cdc,
		keeper:              keeper,
		authKeeper:          ak,
		inflationCalculator: ic,
	}
}

// IsAppModule implements the appmodule.AppModule interface.
func (AppModule) IsAppModule() {}

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

// RegisterLegacyAminoCodec registers the mint module's types on the given LegacyAmino codec.
func (AppModule) RegisterLegacyAminoCodec(cdc *codec.LegacyAmino) {
	types.RegisterLegacyAminoCodec(cdc)
}

// RegisterInterfaces registers the module's interface types
func (AppModule) RegisterInterfaces(registry cdctypes.InterfaceRegistry) {
	types.RegisterInterfaces(registry)
}

// RegisterGRPCGatewayRoutes registers the gRPC Gateway routes for the mint module.
func (AppModule) RegisterGRPCGatewayRoutes(clientCtx client.Context, mux *gwruntime.ServeMux) {
	if err := types.RegisterQueryHandlerClient(context.Background(), mux, types.NewQueryClient(clientCtx)); err != nil {
		panic(err)
	}
}

// RegisterServices registers module services.
func (am AppModule) RegisterServices(registrar grpc.ServiceRegistrar) error {
	types.RegisterMsgServer(registrar, keeper.NewMsgServerImpl(am.keeper))
	types.RegisterQueryServer(registrar, keeper.NewQueryServerImpl(am.keeper))

	return nil
}

// RegisterMigrations registers module migrations.
func (am AppModule) RegisterMigrations(mr appmodule.MigrationRegistrar) error {
	m := keeper.NewMigrator(am.keeper)

	if err := mr.Register(types.ModuleName, 1, m.Migrate1to2); err != nil {
		return fmt.Errorf("failed to migrate x/%s from version 1 to 2: %w", types.ModuleName, err)
	}

	return nil
}

// DefaultGenesis returns default genesis state as raw bytes for the mint module.
func (AppModule) DefaultGenesis(cdc codec.JSONCodec) json.RawMessage {
	return cdc.MustMarshalJSON(types.DefaultGenesisState())
}

// ValidateGenesis performs genesis state validation for the mint module.
func (AppModule) ValidateGenesis(cdc codec.JSONCodec, config client.TxEncodingConfig, bz json.RawMessage) error {
	var data types.GenesisState
	if err := cdc.UnmarshalJSON(bz, &data); err != nil {
		return fmt.Errorf("failed to unmarshal %s genesis state: %w", types.ModuleName, err)
	}

	return types.ValidateGenesis(data)
}

// InitGenesis performs genesis initialization for the mint module.
func (am AppModule) InitGenesis(ctx context.Context, cdc codec.JSONCodec, data json.RawMessage) {
	var genesisState types.GenesisState
	cdc.MustUnmarshalJSON(data, &genesisState)

	am.keeper.InitGenesis(ctx, am.authKeeper, &genesisState)
}

// ExportGenesis returns the exported genesis state as raw bytes for the mint
// module.
func (am AppModule) ExportGenesis(ctx context.Context, cdc codec.JSONCodec) json.RawMessage {
	gs := am.keeper.ExportGenesis(ctx)
	return cdc.MustMarshalJSON(gs)
}

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

// BeginBlock returns the begin blocker for the mint module.
func (am AppModule) BeginBlock(ctx context.Context) error {
	return am.keeper.BeginBlocker(ctx, am.inflationCalculator)
}

// AppModuleSimulation functions

// GenerateGenesisState creates a randomized GenState of the mint module.
func (AppModule) GenerateGenesisState(simState *module.SimulationState) {
	simulation.RandomizedGenState(simState)
}

// ProposalMsgs returns msgs used for governance proposals for simulations.
func (AppModule) ProposalMsgs(simState module.SimulationState) []simtypes.WeightedProposalMsg {
	return simulation.ProposalMsgs()
}

// RegisterStoreDecoder registers a decoder for mint module's types.
func (am AppModule) RegisterStoreDecoder(sdr simtypes.StoreDecoderRegistry) {
	sdr[types.StoreKey] = simtypes.NewStoreDecoderFuncFromCollectionsSchema(am.keeper.Schema)
}

// WeightedOperations doesn't return any mint module operation.
func (AppModule) WeightedOperations(_ module.SimulationState) []simtypes.WeightedOperation {
	return nil
}