package gg

import (
	"bytes"
	"strconv"
	"testing"

	. "code.betamike.com/mediocregopher/ginger/gg/grammar"
	"code.betamike.com/mediocregopher/ginger/graph"
	"github.com/stretchr/testify/assert"
)

func TestDecoder(t *testing.T) {
	type test struct {
		in     string
		exp    Located[Value]
		expErr string
	}

	runTests := func(
		t *testing.T, name string, sym Symbol[Located[Value]], tests []test,
	) {
		t.Run(name, func(t *testing.T) {
			for i, test := range tests {
				t.Run(strconv.Itoa(i), func(t *testing.T) {
					r := NewReader(bytes.NewBufferString(test.in))
					got, err := sym.Decode(r)
					if test.expErr != "" {
						assert.Error(t, err)
						assert.Equal(t, test.expErr, err.Error())
					} else if assert.NoError(t, err) {
						assert.True(t,
							test.exp.Value.Equal(got.Value),
							"\nexp:%v\ngot:%v", test.exp, got,
						)
						assert.Equal(t, test.exp.Location, got.Location)
					}
				})
			}
		})
	}

	expNum := func(row, col int, n int64) Located[Value] {
		return Located[Value]{Location{row, col}, Number(n)}
	}

	runTests(t, "number", number, []test{
		{in: `0`, exp: expNum(1, 1, 0)},
		{in: `100`, exp: expNum(1, 1, 100)},
		{in: `-100`, exp: expNum(1, 1, -100)},
		{in: `0foo`, exp: expNum(1, 1, 0)},
		{in: `100foo`, exp: expNum(1, 1, 100)},
	})

	expName := func(row, col int, name string) Located[Value] {
		return Located[Value]{Location{row, col}, Name(name)}
	}

	expGraph := func(row, col int, g *Graph) Located[Value] {
		return Located[Value]{Location{row, col}, Value{Graph: g}}
	}

	runTests(t, "name", name, []test{
		{in: `a`, exp: expName(1, 1, "a")},
		{in: `ab`, exp: expName(1, 1, "ab")},
		{in: `ab2c`, exp: expName(1, 1, "ab2c")},
		{in: `ab2c,`, exp: expName(1, 1, "ab2c")},
	})

	runTests(t, "graph", graphSym, []test{
		{in: `{}`, exp: expGraph(1, 1, new(Graph))},
		{in: `{`, expErr: `1:2: expected '}' or name`},
		{in: `{a}`, expErr: `1:3: expected '='`},
		{in: `{a=}`, expErr: `1:4: expected name or number or graph or tuple`},
		{
			in: `{foo=a}`,
			exp: expGraph(
				1, 1, new(Graph).
					AddValueIn(Name("foo"), graph.ValueOut(None, Name("a"))),
			),
		},
		{
			in: `{ foo = a }`,
			exp: expGraph(
				1, 1, new(Graph).
					AddValueIn(Name("foo"), graph.ValueOut(None, Name("a"))),
			),
		},
		{in: `{1=a}`, expErr: `1:2: expected '}' or name`},
		{in: `{foo=a ,}`, expErr: `1:8: expected '}' or ';' or '<'`},
		{in: `{foo=a`, expErr: `1:7: expected '}' or ';' or '<'`},
		{
			in: `{foo=a<b}`,
			exp: expGraph(
				1, 1, new(Graph).
					AddValueIn(
						Name("foo"),
						graph.ValueOut(Some(Name("a")), Name("b")),
					),
			),
		},
		{
			in: `{foo=a< b <c}`,
			exp: expGraph(
				1, 1, new(Graph).
					AddValueIn(
						Name("foo"),
						graph.TupleOut(
							Some(Name("a")),
							graph.ValueOut(
								Some(Name("b")),
								Name("c"),
							),
						),
					),
			),
		},
		{
			in: `{foo =a<b<c<1 }`,
			exp: expGraph(
				1, 1, new(Graph).
					AddValueIn(
						Name("foo"),
						graph.TupleOut(
							Some(Name("a")),
							graph.TupleOut(
								Some(Name("b")),
								graph.ValueOut(
									Some(Name("c")),
									Number(1),
								),
							),
						),
					),
			),
		},
		{
			in: `{foo=a<b ; }`,
			exp: expGraph(
				1, 1, new(Graph).
					AddValueIn(
						Name("foo"),
						graph.ValueOut(
							Some(Name("a")),
							Name("b"),
						),
					),
			),
		},
		{
			in: `{foo=a<b;bar=c}`,
			exp: expGraph(
				1, 1, new(Graph).
					AddValueIn(
						Name("foo"),
						graph.ValueOut(
							Some(Name("a")),
							Name("b"),
						),
					).
					AddValueIn(
						Name("bar"),
						graph.ValueOut(None, Name("c")),
					),
			),
		},
		{
			in: `{foo= a<{ baz=1 } ; bar=c}`,
			exp: expGraph(
				1, 1, new(Graph).
					AddValueIn(
						Name("foo"),
						graph.ValueOut(
							Some(Name("a")),
							Value{Graph: new(Graph).AddValueIn(
								Name("baz"),
								graph.ValueOut(None, Number(1)),
							)},
						),
					).
					AddValueIn(
						Name("bar"),
						graph.ValueOut(None, Name("c")),
					),
			),
		},
		{
			in: `{foo= {baz=1} <a; bar=c}`,
			exp: expGraph(
				1, 1, new(Graph).
					AddValueIn(
						Name("foo"),
						graph.ValueOut(
							Some(Value{Graph: new(Graph).AddValueIn(
								Name("baz"),
								graph.ValueOut(None, Number(1)),
							)}),
							Name("a"),
						),
					).
					AddValueIn(
						Name("bar"),
						graph.ValueOut(None, Name("c")),
					),
			),
		},
	})

	runTests(t, "tuple", graphSym, []test{
		{
			in: `{foo=(a)}`,
			exp: expGraph(
				1, 1, new(Graph).
					AddValueIn(
						Name("foo"),
						graph.ValueOut(None, Name("a")),
					),
			),
		},
		{
			in: `{foo=(a<b)}`,
			exp: expGraph(
				1, 1, new(Graph).
					AddValueIn(
						Name("foo"),
						graph.ValueOut(
							Some(Name("a")),
							Name("b"),
						),
					),
			),
		},
		{
			in: `{foo=a<(b)}`,
			exp: expGraph(
				1, 1, new(Graph).
					AddValueIn(
						Name("foo"),
						graph.ValueOut(
							Some(Name("a")),
							Name("b"),
						),
					),
			),
		},
		{
			in: `{foo=a<(b,c)}`,
			exp: expGraph(
				1, 1, new(Graph).
					AddValueIn(
						Name("foo"),
						graph.TupleOut(
							Some(Name("a")),
							graph.ValueOut(None, Name("b")),
							graph.ValueOut(None, Name("c")),
						),
					),
			),
		},
		{
			in: `{foo=a<(b<c)}`,
			exp: expGraph(
				1, 1, new(Graph).
					AddValueIn(
						Name("foo"),
						graph.TupleOut(
							Some(Name("a")),
							graph.TupleOut(
								Some(Name("b")),
								graph.ValueOut(None, Name("c")),
							),
						),
					),
			),
		},
		{
			in: `{foo=a<(b<(c))}`,
			exp: expGraph(
				1, 1, new(Graph).
					AddValueIn(
						Name("foo"),
						graph.TupleOut(
							Some(Name("a")),
							graph.TupleOut(
								Some(Name("b")),
								graph.ValueOut(None, Name("c")),
							),
						),
					),
			),
		},
		{
			in: `{foo=a<(b<(c,d<1))}`,
			exp: expGraph(
				1, 1, new(Graph).
					AddValueIn(
						Name("foo"),
						graph.TupleOut(
							Some(Name("a")),
							graph.TupleOut(
								Some(Name("b")),
								graph.ValueOut(None, Name("c")),
								graph.ValueOut(
									Some(Name("d")),
									Number(1),
								),
							),
						),
					),
			),
		},
		{
			in: `{foo=a<(b<( ( (c) ) ))}`,
			exp: expGraph(
				1, 1, new(Graph).
					AddValueIn(
						Name("foo"),
						graph.TupleOut(
							Some(Name("a")),
							graph.TupleOut(
								Some(Name("b")),
								graph.ValueOut(None, Name("c")),
							),
						),
					),
			),
		},
	})

	runTests(t, "comment", graphSym, []test{
		{
			in:  "*\n{}",
			exp: expGraph(2, 1, new(Graph)),
		},
		{
			in:  "* ignore me!\n{}",
			exp: expGraph(2, 1, new(Graph)),
		},
		{
			in:  "{* ignore me!\n}",
			exp: expGraph(1, 1, new(Graph)),
		},
		{
			in: "{foo* ignore me!\n  =  a}",
			exp: expGraph(
				1, 1, new(Graph).
					AddValueIn(
						Name("foo"),
						graph.ValueOut(None, Name("a")),
					),
			),
		},
		{
			in: "{foo  =  a* ignore me!\n}",
			exp: expGraph(
				1, 1, new(Graph).
					AddValueIn(
						Name("foo"),
						graph.ValueOut(None, Name("a")),
					),
			),
		},
	})
}