// Copyright 2023 The XDC Network Authors
// This file is part of the XDC Network library.

package ethapi

import (
	"context"
	"math/big"
	"testing"

	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/common/hexutil"
)

func TestGetMasternodes(t *testing.T) {
	// Setup mock backend
	// This is a placeholder test - full implementation would use testutil
	
	t.Run("returns masternode list", func(t *testing.T) {
		// Test would verify GetMasternodes returns correct list
	})
	
	t.Run("handles empty epoch", func(t *testing.T) {
		// Test would verify behavior when epoch has no masternodes
	})
}

func TestGetCandidates(t *testing.T) {
	t.Run("returns candidate list", func(t *testing.T) {
		// Test would verify GetCandidates returns correct list
	})
}

func TestGetCandidateInfo(t *testing.T) {
	t.Run("returns candidate info", func(t *testing.T) {
		// Test would verify candidate info fields
	})
	
	t.Run("handles non-existent candidate", func(t *testing.T) {
		// Test error handling for invalid candidate
	})
}

func TestGetBlockSignersByNumber(t *testing.T) {
	t.Run("returns signers for block", func(t *testing.T) {
		// Test would verify signers list
	})
}

func TestXDCRewardCalculation(t *testing.T) {
	tests := []struct {
		name           string
		blockNumber    uint64
		expectedReward *big.Int
	}{
		{
			name:           "genesis block has no reward",
			blockNumber:    0,
			expectedReward: big.NewInt(0),
		},
		{
			name:           "regular block has standard reward",
			blockNumber:    100,
			expectedReward: new(big.Int).Mul(big.NewInt(250), big.NewInt(1e18)), // 250 XDC
		},
	}
	
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			// Test implementation would go here
		})
	}
}

func TestXDCEpochCalculation(t *testing.T) {
	epochSize := uint64(900)
	
	tests := []struct {
		blockNumber   uint64
		expectedEpoch uint64
	}{
		{0, 0},
		{899, 0},
		{900, 1},
		{1800, 2},
		{2700, 3},
	}
	
	for _, tt := range tests {
		epoch := tt.blockNumber / epochSize
		if epoch != tt.expectedEpoch {
			t.Errorf("Block %d: expected epoch %d, got %d", tt.blockNumber, tt.expectedEpoch, epoch)
		}
	}
}

func TestGapBlockCalculation(t *testing.T) {
	epochSize := uint64(900)
	gapSize := uint64(50)
	
	tests := []struct {
		blockNumber uint64
		isGapBlock  bool
	}{
		{0, false},
		{849, false},
		{850, true},  // epoch 1 gap block (900 - 50 = 850)
		{851, false},
		{1750, true}, // epoch 2 gap block (1800 - 50 = 1750)
	}
	
	for _, tt := range tests {
		isGap := tt.blockNumber % epochSize == epochSize - gapSize
		if isGap != tt.isGapBlock {
			t.Errorf("Block %d: expected isGapBlock=%v, got %v", tt.blockNumber, tt.isGapBlock, isGap)
		}
	}
}

func TestHexutilConversions(t *testing.T) {
	// Test hexutil conversions used in XDC API
	
	t.Run("uint64 conversion", func(t *testing.T) {
		val := uint64(12345)
		hex := hexutil.Uint64(val)
		if uint64(hex) != val {
			t.Errorf("Expected %d, got %d", val, uint64(hex))
		}
	})
	
	t.Run("big int conversion", func(t *testing.T) {
		val := big.NewInt(1000000000000000000)
		hex := (*hexutil.Big)(val)
		if hex.ToInt().Cmp(val) != 0 {
			t.Errorf("Big int conversion mismatch")
		}
	})
}

func TestMasternodeAddress(t *testing.T) {
	// Test masternode address validation
	validAddr := common.HexToAddress("0x0000000000000000000000000000000000000001")
	
	if validAddr == (common.Address{}) {
		t.Error("Expected non-zero address")
	}
}

// Mock backend for testing
type mockXDCBackend struct {
	masternodes map[uint64][]common.Address
	candidates  []common.Address
}

func newMockXDCBackend() *mockXDCBackend {
	return &mockXDCBackend{
		masternodes: make(map[uint64][]common.Address),
		candidates:  make([]common.Address, 0),
	}
}

func (b *mockXDCBackend) GetMasternodes(epoch uint64) []common.Address {
	return b.masternodes[epoch]
}

func (b *mockXDCBackend) GetCandidates() []common.Address {
	return b.candidates
}

func (b *mockXDCBackend) SetMasternodes(epoch uint64, addrs []common.Address) {
	b.masternodes[epoch] = addrs
}

func (b *mockXDCBackend) SetCandidates(addrs []common.Address) {
	b.candidates = addrs
}

// Benchmark tests
func BenchmarkGetMasternodes(b *testing.B) {
	backend := newMockXDCBackend()
	
	// Setup 150 masternodes
	masternodes := make([]common.Address, 150)
	for i := 0; i < 150; i++ {
		masternodes[i] = common.BigToAddress(big.NewInt(int64(i + 1)))
	}
	backend.SetMasternodes(1, masternodes)
	
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		_ = backend.GetMasternodes(1)
	}
}

func BenchmarkEpochCalculation(b *testing.B) {
	epochSize := uint64(900)
	
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		_ = uint64(i) / epochSize
	}
}

// Context helpers for tests
func testContext() context.Context {
	return context.Background()
}