package compiler_test

import (
	"fmt"
	"math/big"
	"os"
	"strings"
	"testing"

	"github.com/nspcc-dev/neo-go/pkg/compiler"
	"github.com/nspcc-dev/neo-go/pkg/vm/opcode"
	"github.com/stretchr/testify/require"
)

func checkCallCount(t *testing.T, src string, expectedCall, expectedInitSlot, expectedLocalsMain int) {
	checkInstrCount(t, src, -1, expectedCall, expectedInitSlot, expectedLocalsMain)
}

func checkInstrCount(t *testing.T, src string, expectedSSlotCount, expectedCall, expectedInitSlot, expectedLocalsMain int) {
	v, sp, _ := vmAndCompileInterop(t, src)
	v.PrintOps(os.Stdout)
	mainStart := -1
	for _, m := range sp.info.Methods {
		if m.Name.Name == "main" {
			mainStart = int(m.Range.Start)
		}
	}
	require.True(t, mainStart >= 0)

	ctx := v.Context()
	actualCall := 0
	actualInitSlot := 0

	for op, param, err := ctx.Next(); ; op, param, err = ctx.Next() {
		require.NoError(t, err)
		switch op {
		case opcode.INITSSLOT:
			if expectedSSlotCount == -1 {
				continue
			}
			if expectedSSlotCount == 0 {
				t.Fatalf("no INITSSLOT expected, found at %d with %d cells", ctx.IP(), param[0])
			}
			require.Equal(t, expectedSSlotCount, int(param[0]))
		case opcode.CALL, opcode.CALLL:
			actualCall++
		case opcode.INITSLOT:
			actualInitSlot++
			if ctx.IP() == mainStart && expectedLocalsMain >= 0 {
				require.Equal(t, expectedLocalsMain, int(param[0]))
			}
		}
		if ctx.IP() == ctx.LenInstr() {
			break
		}
	}
	if expectedCall != -1 {
		require.Equal(t, expectedCall, actualCall)
	}
	if expectedInitSlot != -1 {
		require.Equal(t, expectedInitSlot, actualInitSlot)
	}
}

func TestInline(t *testing.T) {
	srcTmpl := `package foo
	import "github.com/nspcc-dev/neo-go/pkg/compiler/testdata/inline"
	import "github.com/nspcc-dev/neo-go/pkg/compiler/testdata/foo"
	var _ = foo.Dummy
	type pair struct { a, b int }
	type triple struct {
		a int
		b pair
	}
	var Num = 1
	func Main() int {
		%s
	}
	// local alias
	func sum(a, b int) int {
		return 42
	}`
	t.Run("no return", func(t *testing.T) {
		src := fmt.Sprintf(srcTmpl, `inline.NoArgsNoReturn()
			return 1`)
		checkCallCount(t, src, 0, 0, 0)
		eval(t, src, big.NewInt(1))
	})
	t.Run("has return, dropped", func(t *testing.T) {
		src := fmt.Sprintf(srcTmpl, `inline.NoArgsReturn1()
			return 2`)
		checkCallCount(t, src, 0, 0, 0)
		eval(t, src, big.NewInt(2))
	})
	t.Run("drop twice", func(t *testing.T) {
		src := fmt.Sprintf(srcTmpl, `inline.DropInsideInline()
			return 42`)
		checkCallCount(t, src, 0, 0, 0)
		eval(t, src, big.NewInt(42))
	})
	t.Run("no args return 1", func(t *testing.T) {
		src := fmt.Sprintf(srcTmpl, `return inline.NoArgsReturn1()`)
		checkCallCount(t, src, 0, 0, 0)
		eval(t, src, big.NewInt(1))
	})
	t.Run("sum", func(t *testing.T) {
		src := fmt.Sprintf(srcTmpl, `return inline.Sum(1, 2)`)
		checkCallCount(t, src, 0, 0, 0)
		eval(t, src, big.NewInt(3))
	})
	t.Run("sum squared (nested inline)", func(t *testing.T) {
		src := fmt.Sprintf(srcTmpl, `return inline.SumSquared(1, 2)`)
		checkCallCount(t, src, 0, 0, 0)
		eval(t, src, big.NewInt(9))
	})
	t.Run("inline function in inline function parameter", func(t *testing.T) {
		src := fmt.Sprintf(srcTmpl, `return inline.Sum(inline.SumSquared(1, 2), inline.Sum(3, 4))`)
		checkCallCount(t, src, 0, 1, 2)
		eval(t, src, big.NewInt(9+3+4))
	})
	t.Run("global name clash", func(t *testing.T) {
		src := fmt.Sprintf(srcTmpl, `return inline.GetSumSameName()`)
		checkCallCount(t, src, 0, 0, 0)
		eval(t, src, big.NewInt(42))
	})
	t.Run("local name clash", func(t *testing.T) {
		src := fmt.Sprintf(srcTmpl, `return inline.Sum(inline.SumSquared(1, 2), sum(3, 4))`)
		checkCallCount(t, src, 1, 2, 2)
		eval(t, src, big.NewInt(51))
	})
	t.Run("var args, empty", func(t *testing.T) {
		src := fmt.Sprintf(srcTmpl, `return inline.VarSum(11)`)
		checkCallCount(t, src, 0, 1, 3)
		eval(t, src, big.NewInt(11))
	})
	t.Run("var args, direct", func(t *testing.T) {
		src := fmt.Sprintf(srcTmpl, `return inline.VarSum(11, 14, 17)`)
		checkCallCount(t, src, 0, 1, 3)
		eval(t, src, big.NewInt(42))
	})
	t.Run("var args, array", func(t *testing.T) {
		src := fmt.Sprintf(srcTmpl, `arr := []int{14, 17} 
			return inline.VarSum(11, arr...)`)
		checkCallCount(t, src, 0, 1, 3)
		eval(t, src, big.NewInt(42))
	})
	t.Run("globals", func(t *testing.T) {
		src := fmt.Sprintf(srcTmpl, `return inline.Concat(Num)`)
		checkCallCount(t, src, 0, 0, 0)
		eval(t, src, big.NewInt(221))
	})
	t.Run("locals, alias", func(t *testing.T) {
		src := fmt.Sprintf(srcTmpl, `num := 1; return inline.Concat(num)`)
		checkCallCount(t, src, 0, 1, 1)
		eval(t, src, big.NewInt(221))
	})
	t.Run("selector, global", func(t *testing.T) {
		src := fmt.Sprintf(srcTmpl, `return inline.Sum(inline.A, 2)`)
		checkCallCount(t, src, 0, 0, 0)
		eval(t, src, big.NewInt(3))
	})
	t.Run("selector, struct, simple", func(t *testing.T) {
		src := fmt.Sprintf(srcTmpl, `x := pair{a: 1, b: 2}; return inline.Sum(x.b, 1)`)
		checkCallCount(t, src, 0, 1, 1)
		eval(t, src, big.NewInt(3))
	})
	t.Run("selector, struct, complex", func(t *testing.T) {
		src := fmt.Sprintf(srcTmpl, `x := triple{a: 1, b: pair{a: 2, b: 3}}
				return inline.Sum(x.b.a, 1)`)
		checkCallCount(t, src, 0, 1, 1)
		eval(t, src, big.NewInt(3))
	})
	t.Run("expression", func(t *testing.T) {
		src := fmt.Sprintf(srcTmpl, `x, y := 1, 2
				return inline.Sum(x+y, y*2)`)
		checkCallCount(t, src, 0, 1, 2)
		eval(t, src, big.NewInt(7))
	})
	t.Run("foreign package call", func(t *testing.T) {
		src := fmt.Sprintf(srcTmpl, `return inline.Sum(foo.Bar(), foo.Dummy+1)`)
		checkCallCount(t, src, 1, 1, 1)
		eval(t, src, big.NewInt(3))
	})
}

func TestIssue1879(t *testing.T) {
	src := `package foo
	import "github.com/nspcc-dev/neo-go/pkg/interop/runtime"
	func Main() int {
		data := "main is called"
		runtime.Log("log " + string(data))
		return 42
	}`
	checkCallCount(t, src, 0, 1, 1)
}

func TestInlineInLoop(t *testing.T) {
	t.Run("simple", func(t *testing.T) {
		src := `package foo
		import "github.com/nspcc-dev/neo-go/pkg/interop/storage"
		import "github.com/nspcc-dev/neo-go/pkg/compiler/testdata/inline"
		func Main() int {
			sum := 0
			values := []int{10, 11}
			for _, v := range values {
				_ = v // use 'v'
				storage.GetContext() // push something on stack to check it's dropped
				sum += inline.VarSum(1, 2, 3, 4)
			}
			return sum
		}`
		eval(t, src, big.NewInt(20))
	})
	t.Run("inlined argument", func(t *testing.T) {
		src := `package foo
		import "github.com/nspcc-dev/neo-go/pkg/interop/runtime"
		import "github.com/nspcc-dev/neo-go/pkg/interop/storage"
		import "github.com/nspcc-dev/neo-go/pkg/compiler/testdata/inline"
		func Main() int {
			sum := 0
			values := []int{10, 11}
			for _, v := range values {
				_  = v // use 'v'
				storage.GetContext() // push something on stack to check it's dropped
				sum += inline.VarSum(1, 2, 3, runtime.GetTime()) // runtime.GetTime always returns 4 in these tests
			}
			return sum
		}`
		eval(t, src, big.NewInt(20))
	})
	t.Run("check clean stack on return", func(t *testing.T) {
		src := `package foo
		import "github.com/nspcc-dev/neo-go/pkg/interop/storage"
		import "github.com/nspcc-dev/neo-go/pkg/compiler/testdata/inline"
		func Main() int {
			values := []int{10, 11, 12}
			for _, v := range values {
				storage.GetContext() // push something on stack to check it's dropped
				if v == 11 {
					return inline.VarSum(2, 20, 200)
				}
			}
			return 0
		}`
		eval(t, src, big.NewInt(222))
	})
}

func TestInlineInSwitch(t *testing.T) {
	src := `package foo
	import "github.com/nspcc-dev/neo-go/pkg/compiler/testdata/inline"
	func Main() int {
		switch inline.VarSum(1, 2) {
		case inline.VarSum(3, 1):
			return 10
		case inline.VarSum(4, -1):
			return 11
		default:
			return 12
		}
	}`
	eval(t, src, big.NewInt(11))
}

func TestInlineGlobalVariable(t *testing.T) {
	t.Run("simple", func(t *testing.T) {
		src := `package foo
		import "github.com/nspcc-dev/neo-go/pkg/compiler/testdata/inline"
		var a = inline.Sum(1, 2)
		func Main() int {
			return a
		}`
		eval(t, src, big.NewInt(3))
	})
	t.Run("complex", func(t *testing.T) {
		src := `package foo
		import "github.com/nspcc-dev/neo-go/pkg/compiler/testdata/inline"
		var a = inline.Sum(3, 4)
		var b = inline.SumSquared(1, 2) 
		var c = a + b
		func init() {
			c--
		}
		func Main() int {
			return c
		}`
		eval(t, src, big.NewInt(15))
	})
}

func TestInlineVariadicInInlinedCall(t *testing.T) {
	src := `package foo
		import "github.com/nspcc-dev/neo-go/pkg/compiler/testdata/inline"
		func Main() int {
			return inline.SumSquared(inline.SumVar(3, 4) - 2, 3)
		}`
	eval(t, src, big.NewInt(64))
}

func TestInlineConversion(t *testing.T) {
	src1 := `package foo
	import "github.com/nspcc-dev/neo-go/pkg/compiler/testdata/inline"
	var _ = inline.A
	func Main() int {
		a := 2
		return inline.SumSquared(1, a)
	}`
	b1, err := compiler.Compile("foo.go", strings.NewReader(src1))
	require.NoError(t, err)

	src2 := `package foo
	import "github.com/nspcc-dev/neo-go/pkg/compiler/testdata/inline"
	var _ = inline.A
	func Main() int {
		a := 2
		{
			return (1 + a) * (1 + a)
		}
	}`
	b2, err := compiler.Compile("foo.go", strings.NewReader(src2))
	require.NoError(t, err)
	require.Equal(t, b2, b1)
}

func TestInlineConversionQualified(t *testing.T) {
	src1 := `package foo
	import "github.com/nspcc-dev/neo-go/pkg/compiler/testdata/inline"
	var A = 1
	func Main() int {
		return inline.Concat(A)
	}`
	b1, err := compiler.Compile("foo.go", strings.NewReader(src1))
	require.NoError(t, err)

	src2 := `package foo
	import "github.com/nspcc-dev/neo-go/pkg/compiler/testdata/inline"
	import "github.com/nspcc-dev/neo-go/pkg/compiler/testdata/inline/b"
	var A = 1
	func Main() int {
		return A * 100 + b.A * 10 + inline.A
	}`
	b2, err := compiler.Compile("foo.go", strings.NewReader(src2))
	require.NoError(t, err)
	require.Equal(t, b2, b1)
}

func TestPackageVarsInInlinedCalls(t *testing.T) {
	src := `package foo
		import "github.com/nspcc-dev/neo-go/pkg/compiler/testdata/inline"
		import "github.com/nspcc-dev/neo-go/pkg/compiler/testdata/inline/b"
		func Main() int {
			return inline.Sum(inline.A, b.A)
		}`
	eval(t, src, big.NewInt(13))
}

func TestInlinedMethod(t *testing.T) {
	src := `package foo
	import "github.com/nspcc-dev/neo-go/pkg/compiler/testdata/inline"
	func Main() int {
		// It's important for this variable to not be named 't'.
		var z inline.T
		i := z.Inc(42)
		if i != 0 || z.N != 42 {
			return 0
		}
		i = z.Inc(100500)
		if i != 42 {
			return 0
		}
		return z.N
	}`
	eval(t, src, big.NewInt(100542))
}

func TestInlinedMethodWithPointer(t *testing.T) {
	src := `package foo
	import "github.com/nspcc-dev/neo-go/pkg/compiler/testdata/inline"
	func Main() int {
		// It's important for this variable to not be named 't'.
		var z = &inline.T{}
		i := z.Inc(42)
		if i != 0 || z.N != 42 {
			return 0
		}
		i = z.Inc(100500)
		if i != 42 {
			return 0
		}
		return z.N
	}`
	eval(t, src, big.NewInt(100542))
}

func TestInlineConditionalReturn(t *testing.T) {
	srcTmpl := `package foo
	import "github.com/nspcc-dev/neo-go/pkg/compiler/testdata/inline/c"
	func Main() int {
		x := %d
		if c.Is42(x) {
			return 100
		}
		return 10
	}`
	t.Run("true", func(t *testing.T) {
		eval(t, fmt.Sprintf(srcTmpl, 123), big.NewInt(10))
	})
	t.Run("false", func(t *testing.T) {
		eval(t, fmt.Sprintf(srcTmpl, 42), big.NewInt(100))
	})
}

func TestInlineDoubleConditionalReturn(t *testing.T) {
	srcTmpl := `package foo
	import "github.com/nspcc-dev/neo-go/pkg/compiler/testdata/inline/c"
	func Main() int {
		return c.Transform(%d, %d)
	}`

	testCase := []struct {
		name         string
		a, b, result int
	}{
		{"true, true, small", 42, 3, 6},
		{"true, true, big", 42, 15, 15},
		{"true, false", 42, 42, 42},
		{"false, true", 3, 11, 6},
		{"false, false", 3, 42, 6},
	}

	for _, tc := range testCase {
		t.Run(tc.name, func(t *testing.T) {
			eval(t, fmt.Sprintf(srcTmpl, tc.a, tc.b), big.NewInt(int64(tc.result)))
		})
	}
}