package staking

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

	gwruntime "github.com/grpc-ecosystem/grpc-gateway/runtime"
	"github.com/spf13/cobra"
	"google.golang.org/grpc"

	"cosmossdk.io/core/appmodule"
	"cosmossdk.io/core/legacy"
	"cosmossdk.io/core/registry"
	"cosmossdk.io/depinject"
	"cosmossdk.io/x/staking/client/cli"
	"cosmossdk.io/x/staking/keeper"
	"cosmossdk.io/x/staking/types"

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

const (
	consensusVersion uint64 = 6
)

var (
	_ module.AppModuleSimulation = AppModule{}
	_ module.HasAminoCodec       = AppModule{}
	_ module.HasGRPCGateway      = AppModule{}
	_ module.HasInvariants       = AppModule{}
	_ module.HasABCIGenesis      = AppModule{}
	_ module.HasABCIEndBlock     = AppModule{}

	_ appmodule.AppModule             = AppModule{}
	_ appmodule.HasServices           = AppModule{}
	_ appmodule.HasMigrations         = AppModule{}
	_ appmodule.HasRegisterInterfaces = AppModule{}

	_ depinject.OnePerModuleType = AppModule{}
)

// AppModule implements an application module for the staking module.
type AppModule struct {
	cdc           codec.Codec
	keeper        *keeper.Keeper
	accountKeeper types.AccountKeeper
	bankKeeper    types.BankKeeper
}

// NewAppModule creates a new AppModule object
func NewAppModule(
	cdc codec.Codec,
	keeper *keeper.Keeper,
	ak types.AccountKeeper,
	bk types.BankKeeper,
) AppModule {
	return AppModule{
		cdc:           cdc,
		keeper:        keeper,
		accountKeeper: ak,
		bankKeeper:    bk,
	}
}

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

// Name returns the staking module's name.
// Deprecated: kept for legacy reasons.
func (AppModule) Name() string {
	return types.ModuleName
}

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

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

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

// GetTxCmd returns the root tx command for the staking module.
func (AppModule) GetTxCmd() *cobra.Command {
	return cli.NewTxCmd()
}

// RegisterInvariants registers the staking module invariants.
func (am AppModule) RegisterInvariants(ir sdk.InvariantRegistry) {
	keeper.RegisterInvariants(ir, am.keeper)
}

// RegisterServices registers module services.
func (am AppModule) RegisterServices(registrar grpc.ServiceRegistrar) error {
	types.RegisterMsgServer(registrar, keeper.NewMsgServerImpl(am.keeper))
	types.RegisterQueryServer(registrar, keeper.NewQuerier(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)
	}
	if err := mr.Register(types.ModuleName, 2, m.Migrate2to3); err != nil {
		return fmt.Errorf("failed to migrate x/%s from version 2 to 3: %w", types.ModuleName, err)
	}
	if err := mr.Register(types.ModuleName, 3, m.Migrate3to4); err != nil {
		return fmt.Errorf("failed to migrate x/%s from version 3 to 4: %w", types.ModuleName, err)
	}
	if err := mr.Register(types.ModuleName, 4, m.Migrate4to5); err != nil {
		return fmt.Errorf("failed to migrate x/%s from version 4 to 5: %w", types.ModuleName, err)
	}
	if err := mr.Register(types.ModuleName, 5, m.Migrate5to6); err != nil {
		return fmt.Errorf("failed to migrate x/%s from version 5 to 6: %w", types.ModuleName, err)
	}

	return nil
}

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

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

	return ValidateGenesis(&data)
}

// InitGenesis performs genesis initialization for the staking module.
func (am AppModule) InitGenesis(ctx context.Context, data json.RawMessage) ([]appmodule.ValidatorUpdate, error) {
	var genesisState types.GenesisState
	am.cdc.MustUnmarshalJSON(data, &genesisState)
	return am.keeper.InitGenesis(ctx, &genesisState)
}

// ExportGenesis returns the exported genesis state as raw bytes for the staking module.
func (am AppModule) ExportGenesis(ctx context.Context) (json.RawMessage, error) {
	genesis, err := am.keeper.ExportGenesis(ctx)
	if err != nil {
		return nil, err
	}
	marshalJSON, err := am.cdc.MarshalJSON(genesis)
	if err != nil {
		return nil, err
	}
	return marshalJSON, nil
}

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

// EndBlock returns the end blocker for the staking module.
func (am AppModule) EndBlock(ctx context.Context) ([]appmodule.ValidatorUpdate, error) {
	return am.keeper.EndBlocker(ctx)
}