/*
 This source file is part of the Swift.org open source project

 Copyright (c) 2021-2022 Apple Inc. and the Swift project authors
 Licensed under Apache License v2.0 with Runtime Library Exception

 See https://swift.org/LICENSE.txt for license information
 See https://swift.org/CONTRIBUTORS.txt for Swift project authors
*/

import XCTest
@testable import SymbolKit

class SymbolTests: XCTestCase {
    
    func testIsDocCommentFromSameModuleAsSymbol() throws {
        // nil doc comment
        do {
            let jsonData = encodedSymbol(withDocComment: nil).data(using: .utf8)!
            let symbol = try JSONDecoder().decode(SymbolGraph.Symbol.self, from: jsonData)

            XCTAssertNil(symbol._isDocCommentFromSameModule)
            XCTAssertNil(symbol.isDocCommentFromSameModule(symbolModuleName: "Test"))
        }
        
        // without range information
        do {
            let jsonData = encodedSymbol(withDocComment:
                (lines: ["First line", "Second line"], rangeStart: nil, moduleName: nil, fileName: nil)
            ).data(using: .utf8)!
            let symbol = try JSONDecoder().decode(SymbolGraph.Symbol.self, from: jsonData)

            XCTAssertEqual(symbol._isDocCommentFromSameModule, false)
            XCTAssertEqual(symbol.isDocCommentFromSameModule(symbolModuleName: "Test"), false)
        }
        
        // with range information
        do {
            let jsonData = encodedSymbol(withDocComment:
                (lines: ["First line", "Second line"], rangeStart: (line: 2, character: 4), moduleName: nil, fileName: nil)
            ).data(using: .utf8)!
            let symbol = try JSONDecoder().decode(SymbolGraph.Symbol.self, from: jsonData)

            XCTAssertEqual(symbol._isDocCommentFromSameModule, true)
            XCTAssertEqual(symbol.isDocCommentFromSameModule(symbolModuleName: "Test"), true)
        }
        
        // empty doc comment
        do {
            let jsonData = encodedSymbol(withDocComment:
                (lines: [], rangeStart: (line: 2, character: 4), moduleName: nil, fileName: nil)
            ).data(using: .utf8)!
            let symbol = try JSONDecoder().decode(SymbolGraph.Symbol.self, from: jsonData)

            XCTAssertNil(symbol._isDocCommentFromSameModule)
            XCTAssertNil(symbol.isDocCommentFromSameModule(symbolModuleName: "Test"))
        }
    }
    
    func testDocCommentModuleInformation() throws {
        let jsonData = encodedSymbol(withDocComment:
            (lines: ["First line", "Second line"], rangeStart: nil, moduleName: "ModuleName", fileName: "file name")
        ).data(using: .utf8)!
        let symbol = try JSONDecoder().decode(SymbolGraph.Symbol.self, from: jsonData)

        XCTAssertEqual(symbol.docComment?.moduleName, "ModuleName")
        XCTAssertEqual(symbol.docComment?.url?.isFileURL, true)
        XCTAssertEqual(symbol.docComment?.url?.pathComponents.last, "file name")
        
        XCTAssertEqual(symbol.isDocCommentFromSameModule(symbolModuleName: "ModuleName"), true)
        XCTAssertEqual(symbol.isDocCommentFromSameModule(symbolModuleName: "Test"), false)
    }
    
    func testURIStringsThatAreNotValidURLs() throws {
        let uris = [
            "filename.swift",
            "relative/path/to/filename.swift",
            "/absolute/path/to/filename.swift",
            "file:///absolute/path/to/filename.swift",
            
            "relative/path with spaces/to/filename.swift",
            "/absolute/path with spaces/to/filename.swift",
            "file:///absolute/path with spaces/to/filename.swift",
            
            "filename with spaces.swift",
            "relative/path/to/filename with spaces.swift",
            "/absolute/path/to/filename with spaces.swift",
            "file:///absolute/path/to/filename with spaces.swift",
            
            "filename%20with%20escaped%20spaces.swift",
            "relative/path/to/filename%20with%20escaped%20spaces.swift",
            "/absolute/path/to/filename%20with%20escaped%20spaces.swift",
            "file:///absolute/path/to/filename%20with%20escaped%20spaces.swift",
        ]
        
        for uri in uris {
            let inputGraph = """
            {
              "accessLevel" : "public",
              "kind" : {
                "displayName" : "Instance Method",
                "identifier" : "swift.method"
              },
              "pathComponents" : [
                "ClassName",
                "something()"
              ],
              "identifier" : {
                "precise" : "precise-identifier",
                "interfaceLanguage" : "swift"
              },
              "names" : {
                "title" : "something()"
              },
              "location" : {
                "position" : {
                  "character" : 4,
                  "line" : 3
                },
                "uri" : "\(uri)"
              },
              "docComment" : {
                "lines" : [
                  {
                    "range" : {
                      "end" : {
                        "character" : 21,
                        "line": 2
                      },
                      "start" : {
                        "character" : 4,
                        "line" : 2
                      }
                    },
                    "text" : "Doc comment text."
                  }
                ],
                "module" : "SourceModuleName",
                "uri" : "\(uri)"
              },
              "declarationFragments" : [
                {
                  "kind" : "keyword",
                  "spelling" : "func"
                },
                {
                  "kind" : "text",
                  "spelling" : " "
                },
                {
                  "kind" : "identifier",
                  "spelling" : "something"
                },
                {
                  "kind" : "text",
                  "spelling" : "() -> "
                },
                {
                  "kind" : "keyword",
                  "spelling" : "Any"
                }
              ]
            }
            """.data(using: .utf8)!
            
            let symbol = try JSONDecoder().decode(SymbolGraph.Symbol.self, from: inputGraph)
            
            // This doesn't do full percent encoding to preserve the "file://" prefix.
            let expectedAbsoluteURLString = uri.replacingOccurrences(of: " ", with: "%20")
            
            let docComment = try XCTUnwrap(symbol.docComment)
            XCTAssertEqual(docComment.uri, uri)
            XCTAssertNotNil(docComment.url)
            XCTAssertEqual(false, docComment.url?.path.contains("%20"))
            XCTAssertEqual(docComment.url?.absoluteString, expectedAbsoluteURLString)
            
            let location = try XCTUnwrap(symbol.mixins[SymbolGraph.Symbol.Location.mixinKey] as? SymbolGraph.Symbol.Location)
            XCTAssertEqual(location.uri, uri)
            XCTAssertNotNil(location.url)
            XCTAssertEqual(false, location.url?.path.contains("%20"))
            XCTAssertEqual(location.url?.absoluteString, expectedAbsoluteURLString)
        }
    }

    /// Check that a Location mixin without position information still decodes a symbol graph without throwing.
    func testMalformedLocationDoesNotThrow() throws {
        let inputGraph = """
        {
          "accessLevel" : "public",
          "kind" : {
            "displayName" : "Instance Method",
            "identifier" : "swift.method"
          },
          "pathComponents" : [
            "ClassName",
            "something()"
          ],
          "identifier" : {
            "precise" : "precise-identifier",
            "interfaceLanguage" : "swift"
          },
          "names" : {
            "title" : "something()"
          },
          "location" : {
            "uri" : "file:///path/to/someSource.swift"
          },
          "declarationFragments" : [
            {
              "kind" : "keyword",
              "spelling" : "func"
            },
            {
              "kind" : "text",
              "spelling" : " "
            },
            {
              "kind" : "identifier",
              "spelling" : "something"
            },
            {
              "kind" : "text",
              "spelling" : "() -> "
            },
            {
              "kind" : "keyword",
              "spelling" : "Any"
            }
          ]
        }
        """.data(using: .utf8)!

        let symbol = try JSONDecoder().decode(SymbolGraph.Symbol.self, from: inputGraph)
        XCTAssertNil(symbol.mixins[SymbolGraph.Symbol.Location.mixinKey])
    }
 
    /// Check that an Extension mixin keeps the `typeKind` information if available and doesn't throw if it is absent.
    func testOptionalExtensionTypeKindCoding() throws {
        let inputGraphWithTypeKindInformation = """
        {
          "extendedModule": "ExtendedModule",
          "typeKind": "class"
        }
        """.data(using: .utf8)!
    
        let mixinWithTypeKind = try JSONDecoder().decode(SymbolGraph.Symbol.Swift.Extension.self, from: inputGraphWithTypeKindInformation)
        XCTAssert(mixinWithTypeKind.typeKind?.identifier == "class")
        
        let roundTripCodedMixinWithTypeKind = try JSONDecoder().decode(SymbolGraph.Symbol.Swift.Extension.self, from: try JSONEncoder().encode(mixinWithTypeKind))
        
        XCTAssert(roundTripCodedMixinWithTypeKind.typeKind?.identifier == "class")
        
        let inputGraphWithoutTypeKindInformation = """
        {
          "extendedModule": "ExtendedModule",
        }
        """.data(using: .utf8)!
    
        let mixinWithoutTypeKind = try JSONDecoder().decode(SymbolGraph.Symbol.Swift.Extension.self, from: inputGraphWithoutTypeKindInformation)
        XCTAssertNil(mixinWithoutTypeKind.typeKind)
    }
    
    /// Check that custom mixins can be decoded, manipulated, and encoded.
    func testCustomMixinRoundTrip() throws {
        let inputGraph = """
{
  "metadata" : {
    "generator" : "manual",
    "formatVersion" : {
      "major" : 0,
      "minor" : 5,
      "patch" : 3
    }
  },
  "module" : {
    "name" : "ModuleName",
    "platform" : {

    }
  },
  "symbols": [
    {
      "accessLevel" : "public",
      "kind" : {
        "displayName" : "Instance Method",
        "identifier" : "swift.method"
      },
      "pathComponents" : [
        "ClassName",
        "something()"
      ],
      "identifier" : {
        "precise" : "precise-identifier",
        "interfaceLanguage" : "swift"
      },
      "names" : {
        "title" : "something()"
      },
      "declarationFragments" : [
        {
          "kind" : "keyword",
          "spelling" : "func"
        },
        {
          "kind" : "text",
          "spelling" : " "
        },
        {
          "kind" : "identifier",
          "spelling" : "something"
        },
        {
          "kind" : "text",
          "spelling" : "() -> "
        },
        {
          "kind" : "keyword",
          "spelling" : "Any"
        }
      ],
      "custom-Int": {
        "value" : 1
      }
    }],
  "relationships": [
    {
      "kind" : "memberOf",
      "source" : "precise-source",
      "target" : "precise-target",
      "targetFallback" : "Swift.Int",
      "custom-String": {
        "value" : "relationship"
      }
    }]
}
""".data(using: .utf8)!
        
        // prepare encoder and decoder to deal with unknown mixins
        let decoder = JSONDecoder()
        decoder.register(symbolMixins: CustomMixin<Int>.self)
        decoder.register(relationshipMixins: CustomMixin<String>.self)
        
        let encoder = JSONEncoder()
        encoder.register(symbolMixins: CustomMixin<Int>.self, CustomMixin<String>.self)
        encoder.register(relationshipMixins: CustomMixin<String>.self)

        var graph = try decoder.decode(SymbolGraph.self, from: inputGraph)
        
        // check custom mixins are present
        XCTAssertEqual("relationship", graph.relationships[0][mixin: CustomMixin<String>.self]?.value)
        XCTAssertEqual(1, graph.symbols["precise-identifier"]![mixin: CustomMixin<Int>.self]?.value)
        
        // edit values + add new mixin of different type to symbol
        graph.relationships[0][mixin: CustomMixin<String>.self]?.value = "first-relationship"
        graph.symbols["precise-identifier"]![mixin: CustomMixin<Int>.self]?.value = 10
        graph.symbols["precise-identifier"]![mixin: CustomMixin<String>.self] = CustomMixin<String>(value: "second-relationship")
        
        // check edited/new data is found in encoded string
        let outputGraph = String(data: try encoder.encode(graph), encoding: .utf8)!
        XCTAssertTrue(outputGraph.contains("first-relationship"))
        XCTAssertTrue(outputGraph.contains("second-relationship"))
        XCTAssertTrue(outputGraph.contains("10"))
        
        // assert encoding and decoding with unprepared coders does not throw
        _ = try JSONDecoder().decode(SymbolGraph.self, from: inputGraph)
        _ = try JSONEncoder().encode(graph)
    }
}

// MARK: Test Data

private func encodedSymbol(withDocComment: (lines: [String], rangeStart: (line: Int, character: Int)?, moduleName: String?, fileName: String?)?) -> String {
    let docCommentJSON: String
    if let withDocComment = withDocComment {
        let lineList = SymbolGraph.LineList(withDocComment.lines.enumerated().map { index, text in
            let range = withDocComment.rangeStart.map { line, character in
                SymbolGraph.LineList.SourceRange(
                    start: SymbolGraph.LineList.SourceRange.Position(line: line + index, character: character),
                    end:   SymbolGraph.LineList.SourceRange.Position(line: line + index, character: character + text.count)
                )
            }
            return SymbolGraph.LineList.Line(text: text, range: range)
        }, uri: withDocComment.fileName.map({ "file:///path/to/" + $0 }), moduleName: withDocComment.moduleName)
        let encoder = JSONEncoder()
        encoder.outputFormatting = .prettyPrinted
        let data = try! encoder.encode(lineList)
        docCommentJSON = String(data: data, encoding: .utf8)!
    } else {
        docCommentJSON = "null"
    }
    
    return """
    {
      "accessLevel" : "public",
      "kind" : {
        "displayName" : "Instance Method",
        "identifier" : "swift.method"
      },
      "pathComponents" : [
        "ClassName",
        "something()"
      ],
      "identifier" : {
        "precise" : "precise-identifier",
        "interfaceLanguage" : "swift"
      },
      "names" : {
        "title" : "something()"
      },
      "docComment" : \(docCommentJSON),
      "declarationFragments" : [
        {
          "kind" : "keyword",
          "spelling" : "func"
        },
        {
          "kind" : "text",
          "spelling" : " "
        },
        {
          "kind" : "identifier",
          "spelling" : "something"
        },
        {
          "kind" : "text",
          "spelling" : "() -> "
        },
        {
          "kind" : "keyword",
          "spelling" : "Any"
        }
      ]
    }
    """
}

private struct CustomMixin<T>: Mixin where T: Codable {
    static var mixinKey: String { "custom-\(T.self)" }
    
    var value: T
}