// Copyright 2018 The CUE Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package cue

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

	"cuelang.org/go/cue/ast"
	"cuelang.org/go/cue/errors"
)

func TestConvert(t *testing.T) {
	i34 := big.NewInt(34)
	d34 := mkBigInt(34)
	f34 := big.NewFloat(34.0000)
	testCases := []struct {
		goVal interface{}
		want  string
	}{{
		nil, "null",
	}, {
		true, "true",
	}, {
		false, "false",
	}, {
		errors.New("oh noes"), "_|_(oh noes)",
	}, {
		"foo", `"foo"`,
	}, {
		3, "3",
	}, {
		uint(3), "3",
	}, {
		uint8(3), "3",
	}, {
		uint16(3), "3",
	}, {
		uint32(3), "3",
	}, {
		uint64(3), "3",
	}, {
		int8(-3), "-3",
	}, {
		int16(-3), "-3",
	}, {
		int32(-3), "-3",
	}, {
		int64(-3), "-3",
	}, {
		float64(3.1), "3.1",
	}, {
		&i34, "34",
	}, {
		&f34, "34",
	}, {
		&d34, "34",
	}, {
		[]int{1, 2, 3, 4}, "[1,2,3,4]",
	}, {
		[]interface{}{}, "[]",
	}, {
		map[string][]int{
			"a": []int{1},
			"b": []int{3, 4},
		}, "<0>{a: [1], b: [3,4]}",
	}, {
		map[int]int{}, "_|_(builtin map key not a string, but unsupported type int)",
	}, {
		map[int]int{1: 2}, "_|_(builtin map key not a string, but unsupported type int)",
	}, {
		struct {
			a int
			b int
		}{3, 4},
		"<0>{}",
	}, {
		struct {
			A int
			B int
		}{3, 4},
		"<0>{A: 3, B: 4}",
	}, {
		struct {
			A int `json:"a"`
			B int `cue:"b"`
		}{3, 4},
		"<0>{a: 3, b: 4}",
	}, {
		struct {
			A int `json:",bb" cue:"" protobuf:"aa"`
			B int `json:"cc" cue:"bb" protobuf:"aa"`
		}{3, 4},
		"<0>{aa: 3, bb: 4}",
	}, {
		&struct{ A int }{3}, "<0>{A: 3}",
	}, {
		(*struct{ A int })(nil), "null",
	}, {
		reflect.ValueOf(3), "3",
	}}
	inst := getInstance(t, "foo")
	b := ast.NewIdent("dummy")
	for _, tc := range testCases {
		ctx := inst.newContext()
		t.Run("", func(t *testing.T) {
			v := convert(ctx, newNode(b), tc.goVal)
			got := debugStr(ctx, v)
			if got != tc.want {
				t.Errorf("got %q; want %q", got, tc.want)
			}
		})
	}
}

func TestBuiltins(t *testing.T) {
	test := func(pkg, expr string) []*bimport {
		return []*bimport{&bimport{"",
			[]string{fmt.Sprintf("import %q\n(%s)", pkg, expr)},
		}}
	}
	testExpr := func(expr string) []*bimport {
		return []*bimport{&bimport{"",
			[]string{fmt.Sprintf("(%s)", expr)},
		}}
	}
	testCases := []struct {
		instances []*bimport
		emit      string
	}{{
		test("math", "math.Pi"),
		`3.14159265358979323846264338327950288419716939937510582097494459`,
	}, {
		test("math", "math.Floor(math.Pi)"),
		`3`,
	}, {
		test("math", "math.Pi(3)"),
		`_|_(<0>.Pi:cannot call non-function 3.14159265358979323846264338327950288419716939937510582097494459 (type float))`,
	}, {
		test("math", "math.Floor(3, 5)"),
		`_|_(<0>.Floor (3,5):number of arguments does not match (1 vs 2))`,
	}, {
		test("math", `math.Floor("foo")`),
		`_|_(<0>.Floor ("foo"):argument 1 requires type number, found string)`,
	}, {
		test("encoding/hex", `hex.Encode("foo")`),
		`"666f6f"`,
	}, {
		test("encoding/hex", `hex.Decode(hex.Encode("foo"))`),
		`'foo'`,
	}, {
		test("encoding/hex", `hex.Decode("foo")`),
		`_|_(<0>.Decode ("foo"):call error: encoding/hex: invalid byte: U+006F 'o')`,
	}, {
		test("strconv", `strconv.FormatUint(64, 16)`),
		`"40"`,
	}, {
		// Find a better alternative, as this call should go.
		test("strconv", `strconv.FormatFloat(3.02, 300, 4, 64)`),
		`_|_(<0>.FormatFloat (3.02,300,4,64):argument 1 out of range: has 9 > 8 bits)`,
	}, {
		// Find a better alternative, as this call should go.
		test("strconv", `strconv.FormatFloat(3.02, -1, 4, 64)`),
		`_|_(<0>.FormatFloat (3.02,-1,4,64):argument 1 must be a positive integer)`,
	}, {
		// Find a better alternative, as this call should go.
		test("strconv", `strconv.FormatFloat(3.02, 1.0, 4, 64)`),
		`_|_(<0>.FormatFloat (3.02,1.0,4,64):argument 2 requires type int, found float)`,
	}, {
		// Panics
		test("math", `math.Jacobi(1000, 2000)`),
		`_|_(<0>.Jacobi (1000,2000):call error: big: invalid 2nd argument to Int.Jacobi: need odd integer but got 2000)`,
	}, {
		test("math", `math.Jacobi(1000, 201)`),
		`1`,
	}, {
		test("math", `math.Asin(2.0e400)`),
		`_|_(<0>.Asin (2.0e+400):invalid argument 0: cue: value was rounded up)`,
	}, {
		test("encoding/csv", `csv.Decode("1,2,3\n4,5,6")`),
		`[["1","2","3"],["4","5","6"]]`,
	}, {
		test("strconv", `strconv.FormatBool(true)`),
		`"true"`,
	}, {
		test("strings", `strings.Join(["Hello", "World!"], " ")`),
		`"Hello World!"`,
	}, {
		test("strings", `strings.Join([1, 2], " ")`),
		`_|_(<0>.Join ([1,2]," "):list element 1: not of right kind (number vs string))`,
	}, {
		test("math/bits", `bits.Or(0x8, 0x1)`),
		`9`,
	}, {
		testExpr(`len({})`),
		`0`,
	}, {
		testExpr(`len({a: 1, b: 2, <foo>: int, _c: 3})`),
		`2`,
	}, {
		testExpr(`len([1, 2, 3])`),
		`3`,
	}, {
		testExpr(`len("foo")`),
		`3`,
	}, {
		testExpr(`len('f\x20\x20')`),
		`3`,
	}}
	for _, tc := range testCases {
		t.Run("", func(t *testing.T) {
			insts := Build(makeInstances(tc.instances))
			if err := insts[0].Err; err != nil {
				t.Fatal(err)
			}
			got := strings.TrimSpace(fmt.Sprintf("%s\n", insts[0].Value()))
			if got != tc.emit {
				t.Errorf("\n got: %s\nwant: %s", got, tc.emit)
			}
		})
	}
}