// ==========================================================================
//  Squidex Headless CMS
// ==========================================================================
//  Copyright (c) Squidex UG (haftungsbeschraenkt)
//  All rights reserved. Licensed under the MIT license.
// ==========================================================================

using System.Text;
using System.Text.Json;
using Lucene.Net.Analysis.Standard;
using Lucene.Net.Analysis.Util;
using Lucene.Net.Util;
using MongoDB.Bson;
using Squidex.Domain.Apps.Entities.MongoDb.Text;
using Xunit;
using LuceneQueryAnalyzer = Lucene.Net.QueryParsers.Classic.QueryParser;

namespace Squidex.Domain.Apps.Entities.Contents.Text
{
    public class AtlasParsingTests
    {
        private static readonly LuceneQueryVisitor QueryVisitor = new LuceneQueryVisitor();
        private static readonly LuceneQueryAnalyzer QueryParser =
            new LuceneQueryAnalyzer(LuceneVersion.LUCENE_48, "*",
                new StandardAnalyzer(LuceneVersion.LUCENE_48, CharArraySet.EMPTY_SET));
        private static readonly JsonSerializerOptions JsonSerializerOptions = new JsonSerializerOptions
        {
            WriteIndented = true
        };

        [Fact]
        public void Should_parse_term_query()
        {
            var actual = ParseQuery("hello");

            var expected = CreateQuery(new
            {
                text = new
                {
                    path = new
                    {
                        wildcard = "*"
                    },
                    query = "hello"
                }
            });

            Assert.Equal(expected, actual);
        }

        [Fact]
        public void Should_parse_phrase_query()
        {
            var actual = ParseQuery("\"hello dolly\"");

            var expected = CreateQuery(new
            {
                phrase = new
                {
                    path = new
                    {
                        wildcard = "*"
                    },
                    query = new[] { "hello", "dolly" }
                }
            });

            Assert.Equal(expected, actual);
        }

        [Fact]
        public void Should_parse_compound_phrase_query()
        {
            var actual = ParseQuery("title:\"The Right Way\" AND text:go");

            var expected = CreateQuery(new
            {
                compound = new
                {
                    must = new object[]
                    {
                        new
                        {
                            phrase = new
                            {
                                path = "title",
                                query = new[]
                                {
                                    "the",
                                    "right",
                                    "way"
                                }
                            }
                        },
                        new
                        {
                            text = new
                            {
                                path = "text",
                                query = "go"
                            }
                        }
                    }
                }
            });

            Assert.Equal(expected, actual);
        }

        [Fact]
        public void Should_parse_compound_phrase_query_with_widldcard()
        {
            var actual = ParseQuery("title:\"Do it right\" AND right");

            var expected = CreateQuery(new
            {
                compound = new
                {
                    must = new object[]
                    {
                        new
                        {
                            phrase = new
                            {
                                path = "title",
                                query = new[]
                                {
                                    "do",
                                    "it",
                                    "right"
                                }
                            }
                        },
                        new
                        {
                            text = new
                            {
                                path = new
                                {
                                    wildcard = "*"
                                },
                                query = "right"
                            }
                        }
                    }
                }
            });

            Assert.Equal(expected, actual);
        }

        [Fact]
        public void Should_parse_wildcard_query()
        {
            var actual = ParseQuery("te?t");

            var expected = CreateQuery(new
            {
                wildcard = new
                {
                    path = new
                    {
                        wildcard = "*"
                    },
                    query = "te?t"
                }
            });

            Assert.Equal(expected, actual);
        }

        [Fact]
        public void Should_parse_prefix_query()
        {
            var actual = ParseQuery("test*");

            var expected = CreateQuery(new
            {
                wildcard = new
                {
                    path = new
                    {
                        wildcard = "*"
                    },
                    query = "test*"
                }
            });

            Assert.Equal(expected, actual);
        }

        [Fact]
        public void Should_parse_fuzzy_query()
        {
            var actual = ParseQuery("roam~");

            var expected = CreateQuery(new
            {
                text = new
                {
                    path = new
                    {
                        wildcard = "*"
                    },
                    query = "roam",
                    fuzzy = new
                    {
                        maxEdits = 2
                    }
                }
            });

            Assert.Equal(expected, actual);
        }

        [Fact]
        public void Should_parse_fuzzy_query_with_max_edits()
        {
            var actual = ParseQuery("roam~1");

            var expected = CreateQuery(new
            {
                text = new
                {
                    path = new
                    {
                        wildcard = "*"
                    },
                    query = "roam",
                    fuzzy = new
                    {
                        maxEdits = 1
                    }
                }
            });

            Assert.Equal(expected, actual);
        }

        [Fact]
        public void Should_parse_fuzzy_phrase_query_with_slop()
        {
            var actual = ParseQuery("\"jakarta apache\"~10");

            var expected = CreateQuery(new
            {
                phrase = new
                {
                    path = new
                    {
                        wildcard = "*"
                    },
                    query = new[]
                    {
                        "jakarta",
                        "apache"
                    },
                    slop = 10
                }
            });

            Assert.Equal(expected, actual);
        }

        [Fact]
        public void Should_parse_compound_query_with_brackets()
        {
            var actual = ParseQuery("(jakarta OR apache) AND website");

            var expected = CreateQuery(new
            {
                compound = new
                {
                    must = new object[]
                    {
                        new
                        {
                            compound = new
                            {
                                should = new object[]
                                {
                                    new
                                    {
                                        text = new
                                        {
                                            path = new
                                            {
                                                wildcard = "*"
                                            },
                                            query = "jakarta"
                                        }
                                    },
                                    new
                                    {
                                        text = new
                                        {
                                            path = new
                                            {
                                                wildcard = "*"
                                            },
                                            query = "apache"
                                        }
                                    }
                                }
                            }
                        },
                        new
                        {
                            text = new
                            {
                                path = new
                                {
                                    wildcard = "*"
                                },
                                query = "website"
                            }
                        }
                    }
                }
            });

            Assert.Equal(expected, actual);
        }

        [Fact]
        public void Should_parse_compound_query_and_optimize()
        {
            var actual = ParseQuery("title:(+return +\"pink panther\")");

            var expected = CreateQuery(new
            {
                compound = new
                {
                    must = new object[]
                    {
                        new
                        {
                            text = new
                            {
                                path = "title",
                                query = "return"
                            }
                        },
                        new
                        {
                            phrase = new
                            {
                                path = "title",
                                query = new[]
                                {
                                    "pink",
                                    "panther"
                                }
                            }
                        }
                    }
                }
            });

            Assert.Equal(expected, actual);
        }

        [Fact]
        public void Should_parse_range_query()
        {
            var actual = ParseQuery("mod_date:[20020101 TO 20030101]");

            var expected = CreateQuery(new
            {
                range = new
                {
                    path = "mod_date",
                    gte = 20020101,
                    lte = 20030101
                }
            });

            Assert.Equal(expected, actual);
        }

        [Fact]
        public void Should_parse_open_range_query()
        {
            var actual = ParseQuery("mod_date:{20020101 TO 20030101}");

            var expected = CreateQuery(new
            {
                range = new
                {
                    path = "mod_date",
                    gt = 20020101,
                    lt = 20030101
                }
            });

            Assert.Equal(expected, actual);
        }

        private static object CreateQuery(object query)
        {
            return JsonSerializer.Serialize(query, JsonSerializerOptions);
        }

        private static object ParseQuery(string query)
        {
            var luceneQuery = QueryParser.Parse(query);

            var rendered = QueryVisitor.Visit(luceneQuery);

            var jsonStream = new MemoryStream();
            var jsonDocument = JsonDocument.Parse(rendered.ToJson());

            var jsonWriter = new Utf8JsonWriter(jsonStream, new JsonWriterOptions { Indented = true });

            jsonDocument.WriteTo(jsonWriter);

            jsonWriter.Flush();

            return Encoding.UTF8.GetString(jsonStream.ToArray());
        }
    }
}