package cache

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

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

	"github.com/your-org/mev-bot/pkg/types"
)

func createTestPool(address, token0, token1 string, protocol types.ProtocolType) *types.PoolInfo {
	return &types.PoolInfo{
		Address:        common.HexToAddress(address),
		Protocol:       protocol,
		Token0:         common.HexToAddress(token0),
		Token1:         common.HexToAddress(token1),
		Token0Decimals: 18,
		Token1Decimals: 6,
		Reserve0:       big.NewInt(1000000),
		Reserve1:       big.NewInt(500000),
		Liquidity:      big.NewInt(100000),
		IsActive:       true,
	}
}

func TestNewPoolCache(t *testing.T) {
	cache := NewPoolCache()
	if cache == nil {
		t.Fatal("NewPoolCache returned nil")
	}
}

func TestPoolCache_Add(t *testing.T) {
	ctx := context.Background()
	cache := NewPoolCache()

	pool := createTestPool("0x1111", "0x2222", "0x3333", types.ProtocolUniswapV2)

	err := cache.Add(ctx, pool)
	if err != nil {
		t.Fatalf("Add() failed: %v", err)
	}

	// Verify it was added
	retrieved, err := cache.GetByAddress(ctx, pool.Address)
	if err != nil {
		t.Fatalf("GetByAddress() failed: %v", err)
	}

	if retrieved.Address != pool.Address {
		t.Errorf("Retrieved pool address = %v, want %v", retrieved.Address, pool.Address)
	}
}

func TestPoolCache_Add_NilPool(t *testing.T) {
	ctx := context.Background()
	cache := NewPoolCache()

	err := cache.Add(ctx, nil)
	if err == nil {
		t.Error("Add(nil) expected error, got nil")
	}
}

func TestPoolCache_Add_InvalidPool(t *testing.T) {
	ctx := context.Background()
	cache := NewPoolCache()

	// Pool with zero address
	pool := createTestPool("0x0000", "0x2222", "0x3333", types.ProtocolUniswapV2)
	pool.Address = common.Address{}

	err := cache.Add(ctx, pool)
	if err == nil {
		t.Error("Add(invalid pool) expected error, got nil")
	}
}

func TestPoolCache_Add_Update(t *testing.T) {
	ctx := context.Background()
	cache := NewPoolCache()

	pool := createTestPool("0x1111", "0x2222", "0x3333", types.ProtocolUniswapV2)

	// Add pool
	err := cache.Add(ctx, pool)
	if err != nil {
		t.Fatalf("Add() failed: %v", err)
	}

	// Update pool (same address, different reserves)
	updatedPool := createTestPool("0x1111", "0x2222", "0x3333", types.ProtocolUniswapV2)
	updatedPool.Reserve0 = big.NewInt(2000000)

	err = cache.Add(ctx, updatedPool)
	if err != nil {
		t.Fatalf("Add(update) failed: %v", err)
	}

	// Verify it was updated
	retrieved, err := cache.GetByAddress(ctx, pool.Address)
	if err != nil {
		t.Fatalf("GetByAddress() failed: %v", err)
	}

	if retrieved.Reserve0.Cmp(big.NewInt(2000000)) != 0 {
		t.Errorf("Updated pool reserve0 = %v, want %v", retrieved.Reserve0, big.NewInt(2000000))
	}
}

func TestPoolCache_GetByAddress(t *testing.T) {
	ctx := context.Background()
	cache := NewPoolCache()

	pool := createTestPool("0x1111", "0x2222", "0x3333", types.ProtocolUniswapV2)
	cache.Add(ctx, pool)

	tests := []struct {
		name    string
		address common.Address
		wantErr bool
	}{
		{
			name:    "existing pool",
			address: common.HexToAddress("0x1111"),
			wantErr: false,
		},
		{
			name:    "non-existing pool",
			address: common.HexToAddress("0x9999"),
			wantErr: true,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got, err := cache.GetByAddress(ctx, tt.address)

			if tt.wantErr {
				if err == nil {
					t.Error("GetByAddress() expected error, got nil")
				}
				if got != nil {
					t.Error("GetByAddress() expected nil pool on error")
				}
			} else {
				if err != nil {
					t.Errorf("GetByAddress() unexpected error: %v", err)
				}
				if got == nil {
					t.Error("GetByAddress() returned nil pool")
				}
			}
		})
	}
}

func TestPoolCache_GetByTokenPair(t *testing.T) {
	ctx := context.Background()
	cache := NewPoolCache()

	// Add pools with same token pair
	pool1 := createTestPool("0x1111", "0x2222", "0x3333", types.ProtocolUniswapV2)
	pool2 := createTestPool("0x4444", "0x2222", "0x3333", types.ProtocolUniswapV3)

	cache.Add(ctx, pool1)
	cache.Add(ctx, pool2)

	tests := []struct {
		name      string
		token0    common.Address
		token1    common.Address
		wantCount int
	}{
		{
			name:      "existing pair",
			token0:    common.HexToAddress("0x2222"),
			token1:    common.HexToAddress("0x3333"),
			wantCount: 2,
		},
		{
			name:      "existing pair (reversed)",
			token0:    common.HexToAddress("0x3333"),
			token1:    common.HexToAddress("0x2222"),
			wantCount: 2,
		},
		{
			name:      "non-existing pair",
			token0:    common.HexToAddress("0x9999"),
			token1:    common.HexToAddress("0x8888"),
			wantCount: 0,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			pools, err := cache.GetByTokenPair(ctx, tt.token0, tt.token1)
			if err != nil {
				t.Fatalf("GetByTokenPair() error: %v", err)
			}

			if len(pools) != tt.wantCount {
				t.Errorf("GetByTokenPair() count = %d, want %d", len(pools), tt.wantCount)
			}
		})
	}
}

func TestPoolCache_GetByProtocol(t *testing.T) {
	ctx := context.Background()
	cache := NewPoolCache()

	// Add pools with different protocols
	pool1 := createTestPool("0x1111", "0x2222", "0x3333", types.ProtocolUniswapV2)
	pool2 := createTestPool("0x4444", "0x5555", "0x6666", types.ProtocolUniswapV2)
	pool3 := createTestPool("0x7777", "0x8888", "0x9999", types.ProtocolUniswapV3)

	cache.Add(ctx, pool1)
	cache.Add(ctx, pool2)
	cache.Add(ctx, pool3)

	tests := []struct {
		name      string
		protocol  types.ProtocolType
		wantCount int
	}{
		{
			name:      "uniswap v2",
			protocol:  types.ProtocolUniswapV2,
			wantCount: 2,
		},
		{
			name:      "uniswap v3",
			protocol:  types.ProtocolUniswapV3,
			wantCount: 1,
		},
		{
			name:      "curve (none)",
			protocol:  types.ProtocolCurve,
			wantCount: 0,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			pools, err := cache.GetByProtocol(ctx, tt.protocol)
			if err != nil {
				t.Fatalf("GetByProtocol() error: %v", err)
			}

			if len(pools) != tt.wantCount {
				t.Errorf("GetByProtocol() count = %d, want %d", len(pools), tt.wantCount)
			}
		})
	}
}

func TestPoolCache_GetByLiquidity(t *testing.T) {
	ctx := context.Background()
	cache := NewPoolCache()

	// Add pools with different liquidity
	pool1 := createTestPool("0x1111", "0x2222", "0x3333", types.ProtocolUniswapV2)
	pool1.Liquidity = big.NewInt(1000)

	pool2 := createTestPool("0x4444", "0x5555", "0x6666", types.ProtocolUniswapV2)
	pool2.Liquidity = big.NewInt(5000)

	pool3 := createTestPool("0x7777", "0x8888", "0x9999", types.ProtocolUniswapV3)
	pool3.Liquidity = big.NewInt(10000)

	cache.Add(ctx, pool1)
	cache.Add(ctx, pool2)
	cache.Add(ctx, pool3)

	tests := []struct {
		name         string
		minLiquidity *big.Int
		limit        int
		wantCount    int
		wantFirst    *big.Int // Expected liquidity of first result
	}{
		{
			name:         "all pools",
			minLiquidity: big.NewInt(0),
			limit:        0,
			wantCount:    3,
			wantFirst:    big.NewInt(10000),
		},
		{
			name:         "min 2000",
			minLiquidity: big.NewInt(2000),
			limit:        0,
			wantCount:    2,
			wantFirst:    big.NewInt(10000),
		},
		{
			name:         "limit 2",
			minLiquidity: big.NewInt(0),
			limit:        2,
			wantCount:    2,
			wantFirst:    big.NewInt(10000),
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			pools, err := cache.GetByLiquidity(ctx, tt.minLiquidity, tt.limit)
			if err != nil {
				t.Fatalf("GetByLiquidity() error: %v", err)
			}

			if len(pools) != tt.wantCount {
				t.Errorf("GetByLiquidity() count = %d, want %d", len(pools), tt.wantCount)
			}

			if len(pools) > 0 && pools[0].Liquidity.Cmp(tt.wantFirst) != 0 {
				t.Errorf("GetByLiquidity() first liquidity = %v, want %v", pools[0].Liquidity, tt.wantFirst)
			}
		})
	}
}

func TestPoolCache_Update(t *testing.T) {
	ctx := context.Background()
	cache := NewPoolCache()

	pool := createTestPool("0x1111", "0x2222", "0x3333", types.ProtocolUniswapV2)
	cache.Add(ctx, pool)

	// Update reserves
	err := cache.Update(ctx, pool.Address, func(p *types.PoolInfo) error {
		p.Reserve0 = big.NewInt(9999999)
		return nil
	})

	if err != nil {
		t.Fatalf("Update() failed: %v", err)
	}

	// Verify update
	retrieved, err := cache.GetByAddress(ctx, pool.Address)
	if err != nil {
		t.Fatalf("GetByAddress() failed: %v", err)
	}

	if retrieved.Reserve0.Cmp(big.NewInt(9999999)) != 0 {
		t.Errorf("Update() reserve0 = %v, want %v", retrieved.Reserve0, big.NewInt(9999999))
	}
}

func TestPoolCache_Update_NonExistent(t *testing.T) {
	ctx := context.Background()
	cache := NewPoolCache()

	err := cache.Update(ctx, common.HexToAddress("0x9999"), func(p *types.PoolInfo) error {
		return nil
	})

	if err == nil {
		t.Error("Update(non-existent) expected error, got nil")
	}
}

func TestPoolCache_Update_Error(t *testing.T) {
	ctx := context.Background()
	cache := NewPoolCache()

	pool := createTestPool("0x1111", "0x2222", "0x3333", types.ProtocolUniswapV2)
	cache.Add(ctx, pool)

	// Update with error
	testErr := fmt.Errorf("test error")
	err := cache.Update(ctx, pool.Address, func(p *types.PoolInfo) error {
		return testErr
	})

	if err != testErr {
		t.Errorf("Update() error = %v, want %v", err, testErr)
	}
}

func TestPoolCache_Update_InvalidAfterUpdate(t *testing.T) {
	ctx := context.Background()
	cache := NewPoolCache()

	pool := createTestPool("0x1111", "0x2222", "0x3333", types.ProtocolUniswapV2)
	cache.Add(ctx, pool)

	// Make pool invalid
	err := cache.Update(ctx, pool.Address, func(p *types.PoolInfo) error {
		p.Token0Decimals = 0 // Invalid
		return nil
	})

	if err == nil {
		t.Error("Update(invalid) expected error, got nil")
	}
}

func TestPoolCache_Remove(t *testing.T) {
	ctx := context.Background()
	cache := NewPoolCache()

	pool := createTestPool("0x1111", "0x2222", "0x3333", types.ProtocolUniswapV2)
	cache.Add(ctx, pool)

	// Remove pool
	err := cache.Remove(ctx, pool.Address)
	if err != nil {
		t.Fatalf("Remove() failed: %v", err)
	}

	// Verify removal
	_, err = cache.GetByAddress(ctx, pool.Address)
	if err == nil {
		t.Error("GetByAddress() after Remove() expected error, got nil")
	}

	// Verify removed from token pair index
	pools, _ := cache.GetByTokenPair(ctx, pool.Token0, pool.Token1)
	if len(pools) != 0 {
		t.Error("Pool still in token pair index after removal")
	}

	// Verify removed from protocol index
	pools, _ = cache.GetByProtocol(ctx, pool.Protocol)
	if len(pools) != 0 {
		t.Error("Pool still in protocol index after removal")
	}
}

func TestPoolCache_Remove_NonExistent(t *testing.T) {
	ctx := context.Background()
	cache := NewPoolCache()

	err := cache.Remove(ctx, common.HexToAddress("0x9999"))
	if err == nil {
		t.Error("Remove(non-existent) expected error, got nil")
	}
}

func TestPoolCache_Count(t *testing.T) {
	ctx := context.Background()
	cache := NewPoolCache()

	// Initially empty
	count, err := cache.Count(ctx)
	if err != nil {
		t.Fatalf("Count() failed: %v", err)
	}
	if count != 0 {
		t.Errorf("Count() = %d, want 0", count)
	}

	// Add pools
	pool1 := createTestPool("0x1111", "0x2222", "0x3333", types.ProtocolUniswapV2)
	pool2 := createTestPool("0x4444", "0x5555", "0x6666", types.ProtocolUniswapV3)

	cache.Add(ctx, pool1)
	cache.Add(ctx, pool2)

	count, err = cache.Count(ctx)
	if err != nil {
		t.Fatalf("Count() failed: %v", err)
	}
	if count != 2 {
		t.Errorf("Count() = %d, want 2", count)
	}
}

func TestPoolCache_Clear(t *testing.T) {
	ctx := context.Background()
	cache := NewPoolCache()

	// Add pools
	pool1 := createTestPool("0x1111", "0x2222", "0x3333", types.ProtocolUniswapV2)
	pool2 := createTestPool("0x4444", "0x5555", "0x6666", types.ProtocolUniswapV3)

	cache.Add(ctx, pool1)
	cache.Add(ctx, pool2)

	// Clear cache
	err := cache.Clear(ctx)
	if err != nil {
		t.Fatalf("Clear() failed: %v", err)
	}

	// Verify cleared
	count, _ := cache.Count(ctx)
	if count != 0 {
		t.Errorf("Count() after Clear() = %d, want 0", count)
	}
}

func Test_makeTokenPairKey(t *testing.T) {
	token0 := common.HexToAddress("0x1111")
	token1 := common.HexToAddress("0x2222")

	// Should be consistent regardless of order
	key1 := makeTokenPairKey(token0, token1)
	key2 := makeTokenPairKey(token1, token0)

	if key1 != key2 {
		t.Errorf("makeTokenPairKey() not consistent: %s != %s", key1, key2)
	}
}

func Test_removePoolFromSlice(t *testing.T) {
	pool1 := createTestPool("0x1111", "0x2222", "0x3333", types.ProtocolUniswapV2)
	pool2 := createTestPool("0x4444", "0x5555", "0x6666", types.ProtocolUniswapV3)
	pool3 := createTestPool("0x7777", "0x8888", "0x9999", types.ProtocolCurve)

	pools := []*types.PoolInfo{pool1, pool2, pool3}

	// Remove middle pool
	result := removePoolFromSlice(pools, pool2.Address)

	if len(result) != 2 {
		t.Errorf("removePoolFromSlice() length = %d, want 2", len(result))
	}

	if result[0].Address != pool1.Address || result[1].Address != pool3.Address {
		t.Error("removePoolFromSlice() incorrect pools remaining")
	}

	// Remove non-existent pool
	result = removePoolFromSlice(result, common.HexToAddress("0x9999"))
	if len(result) != 2 {
		t.Errorf("removePoolFromSlice(non-existent) length = %d, want 2", len(result))
	}
}