package poj

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

	"cosmossdk.io/core/appmodule"
	"github.com/cosmos/cosmos-sdk/client"
	"github.com/cosmos/cosmos-sdk/codec"
	codectypes "github.com/cosmos/cosmos-sdk/codec/types"
	sdk "github.com/cosmos/cosmos-sdk/types"
	"github.com/cosmos/cosmos-sdk/types/module"
	"github.com/grpc-ecosystem/grpc-gateway/runtime"
	"google.golang.org/grpc"

	"mukan/x/poj/keeper"
	"mukan/x/poj/types"
	"mukan/x/poj/client/cli"
	"github.com/spf13/cobra"
)

var (
	_ module.AppModuleBasic = (*AppModule)(nil)
	_ module.AppModule      = (*AppModule)(nil)
	_ module.HasGenesis     = (*AppModule)(nil)

	_ appmodule.AppModule       = (*AppModule)(nil)
	_ appmodule.HasBeginBlocker = (*AppModule)(nil)
	_ appmodule.HasEndBlocker   = (*AppModule)(nil)
)

// AppModule implements the AppModule interface that defines the inter-dependent methods that modules need to implement
type AppModule struct {
	cdc           codec.Codec
	keeper        keeper.Keeper
	authKeeper    types.AuthKeeper
	bankKeeper    types.BankKeeper
	stakingKeeper types.StakingKeeper
}

func NewAppModule(
	cdc codec.Codec,
	keeper keeper.Keeper,
	authKeeper types.AuthKeeper,
	bankKeeper types.BankKeeper,
	stakingKeeper types.StakingKeeper,
) AppModule {
	return AppModule{
		cdc:           cdc,
		keeper:        keeper,
		authKeeper:    authKeeper,
		bankKeeper:    bankKeeper,
		stakingKeeper: stakingKeeper,
	}
}

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

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

// RegisterLegacyAminoCodec registers the amino codec
func (AppModule) RegisterLegacyAminoCodec(*codec.LegacyAmino) {}

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

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

// GetQueryCmd returns the root query command for the module.
func (AppModule) GetQueryCmd() *cobra.Command {
	return nil
}

// RegisterInterfaces registers a module's interface types and their concrete implementations as proto.Message.
func (AppModule) RegisterInterfaces(registrar codectypes.InterfaceRegistry) {
	types.RegisterInterfaces(registrar)
}

// RegisterServices registers a gRPC query service to respond to the module-specific gRPC queries
func (am AppModule) RegisterServices(registrar grpc.ServiceRegistrar) error {
	types.RegisterMsgServer(registrar, keeper.NewMsgServerImpl(am.keeper))
	types.RegisterQueryServer(registrar, keeper.NewQueryServerImpl(am.keeper))

	return nil
}

// DefaultGenesis returns a default GenesisState for the module, marshalled to json.RawMessage.
// The default GenesisState need to be defined by the module developer and is primarily used for testing.
func (am AppModule) DefaultGenesis(codec.JSONCodec) json.RawMessage {
	return am.cdc.MustMarshalJSON(types.DefaultGenesis())
}

// ValidateGenesis used to validate the GenesisState, given in its json.RawMessage form.
func (am AppModule) ValidateGenesis(_ codec.JSONCodec, _ client.TxEncodingConfig, bz json.RawMessage) error {
	var genState types.GenesisState
	if err := am.cdc.UnmarshalJSON(bz, &genState); err != nil {
		return fmt.Errorf("failed to unmarshal %s genesis state: %w", types.ModuleName, err)
	}

	return genState.Validate()
}

// InitGenesis performs the module's genesis initialization. It returns no validator updates.
func (am AppModule) InitGenesis(ctx sdk.Context, _ codec.JSONCodec, gs json.RawMessage) {
	var genState types.GenesisState
	// Initialize global index to index in genesis state
	if err := am.cdc.UnmarshalJSON(gs, &genState); err != nil {
		panic(fmt.Errorf("failed to unmarshal %s genesis state: %w", types.ModuleName, err))
	}

	if err := am.keeper.InitGenesis(ctx, genState); err != nil {
		panic(fmt.Errorf("failed to initialize %s genesis state: %w", types.ModuleName, err))
	}
}

// ExportGenesis returns the module's exported genesis state as raw JSON bytes.
func (am AppModule) ExportGenesis(ctx sdk.Context, _ codec.JSONCodec) json.RawMessage {
	genState, err := am.keeper.ExportGenesis(ctx)
	if err != nil {
		panic(fmt.Errorf("failed to export %s genesis state: %w", types.ModuleName, err))
	}

	bz, err := am.cdc.MarshalJSON(genState)
	if err != nil {
		panic(fmt.Errorf("failed to marshal %s genesis state: %w", types.ModuleName, err))
	}

	return bz
}

// ConsensusVersion is a sequence number for state-breaking change of the module.
// It should be incremented on each consensus-breaking change introduced by the module.
// To avoid wrong/empty versions, the initial version should be set to 1.
func (AppModule) ConsensusVersion() uint64 { return 1 }

// BeginBlock contains the logic that is automatically triggered at the beginning of each block.
// The begin block implementation is optional.
func (am AppModule) BeginBlock(ctx context.Context) error {
	sdkCtx := sdk.UnwrapSDKContext(ctx)
	proposerAddr := sdkCtx.BlockHeader().ProposerAddress
	if proposerAddr == nil {
		return nil
	}

	// Map ConsAddress to Validator and then to AccountAddress
	validator, err := am.stakingKeeper.ValidatorByConsAddr(sdkCtx, proposerAddr)
	if err != nil {
		// If not found, skip (might happen in genesis or non-validator blocks)
		return nil
	}

	// Operator address is usually what we want to reward
	operatorAddr := validator.GetOperator()
	
	// Convert operator address (valoper) to account address (acc)
	// In Cosmos SDK, operator and account share the same public key but different prefix.
	// For now, we use the string directly if it's already a valid address string, 
	// or we can convert it. 
	// The doc says "Madenci cüzdan adresi".
	
	// Implementation Detail: GetOperator() returns the valoper address.
	// We should convert it to a standard account address for the reward.
	// However, many chains just send to the account associated with the valoper.
	
	// Let's use a helper if available, or just convert via bytes.
	valAddr, err := sdk.ValAddressFromBech32(operatorAddr)
	if err != nil {
		return nil
	}
	accAddr := sdk.AccAddress(valAddr)
	minerAddr := accAddr.String()

	// 1. Apply PoJ logic
	if am.keeper.ProcessBlockReward(ctx, minerAddr) {
		reward := am.keeper.GetBlockReward(ctx)
		// Mint and send reward to miner
		err := am.bankKeeper.MintCoins(sdkCtx, types.ModuleName, sdk.NewCoins(reward))
		if err != nil {
			return err
		}

		err = am.bankKeeper.SendCoinsFromModuleToAccount(sdkCtx, types.ModuleName, accAddr, sdk.NewCoins(reward))
		if err != nil {
			return err
		}
	}

	return nil
}

// EndBlock contains the logic that is automatically triggered at the end of each block.
func (am AppModule) EndBlock(ctx context.Context) error {
	sdkCtx := sdk.UnwrapSDKContext(ctx)
	
	// SAFU Check: If no miner won this block, reward goes to the Törük (Wealth Fund)
	hasWinner := am.keeper.HasBlockWinner(ctx, sdkCtx.BlockHeight())
	if !hasWinner {
		params := am.keeper.GetParams(ctx)
		torukAddr, err := sdk.AccAddressFromBech32(params.TorukAddress)
		if err == nil {
			reward := am.keeper.GetBlockReward(ctx)
			// Mint and send reward to Törük
			err = am.bankKeeper.MintCoins(sdkCtx, types.ModuleName, sdk.NewCoins(reward))
			if err == nil {
				_ = am.bankKeeper.SendCoinsFromModuleToAccount(sdkCtx, types.ModuleName, torukAddr, sdk.NewCoins(reward))
			}
		}
	}

	return nil
}