import XCTest
@testable import DropTwoCore

final class FileNameParserTests: XCTestCase {

    // MARK: - Erfolgreiches Parsen

    func testParsesStandardFileName() {
        let result = FileNameParser.parse("SOMOS-9x16-v3-DE.mp4")

        guard case .parsed(let parsed) = result.outcome else {
            return XCTFail("Erwartete .parsed, bekam \(result.outcome)")
        }
        XCTAssertEqual(parsed.projectName, "SOMOS")
        XCTAssertEqual(parsed.sourceFormatToken, "9x16")
        XCTAssertEqual(parsed.remainder, "v3-DE")
        XCTAssertEqual(parsed.fileExtension, "mp4")
        XCTAssertEqual(parsed.originalFileName, "SOMOS-9x16-v3-DE.mp4")
        XCTAssertEqual(parsed.targetFileName, "SOMOS-4x5-v3-DE.mp4")
    }

    func testProjectNameWithHyphenIsPreserved() {
        let result = FileNameParser.parse("Somos-Pendant-9x16-v3-DE.mp4")

        guard case .parsed(let parsed) = result.outcome else {
            return XCTFail("Erwartete .parsed, bekam \(result.outcome)")
        }
        XCTAssertEqual(parsed.projectName, "Somos-Pendant")
        XCTAssertEqual(parsed.targetFileName, "Somos-Pendant-4x5-v3-DE.mp4")
    }

    func testLanguageSegmentWithHyphenIsPreserved() {
        let result = FileNameParser.parse("SOMOS-9x16-v3-EN-US.mp4")

        guard case .parsed(let parsed) = result.outcome else {
            return XCTFail("Erwartete .parsed, bekam \(result.outcome)")
        }
        XCTAssertEqual(parsed.projectName, "SOMOS")
        XCTAssertEqual(parsed.remainder, "v3-EN-US")
        XCTAssertEqual(parsed.targetFileName, "SOMOS-4x5-v3-EN-US.mp4")
    }

    func testCaseInsensitiveFormatTokenIsRecognized() {
        let result = FileNameParser.parse("somos-9X16-v3-de.mp4")

        guard case .parsed(let parsed) = result.outcome else {
            return XCTFail("Erwartete .parsed, bekam \(result.outcome)")
        }
        // Sonst unveränderte Schreibweise bleibt erhalten.
        XCTAssertEqual(parsed.projectName, "somos")
        XCTAssertEqual(parsed.sourceFormatToken, "9X16")
        XCTAssertEqual(parsed.remainder, "v3-de")
        XCTAssertEqual(parsed.targetFileName, "somos-4x5-v3-de.mp4")
    }

    func testFileExtensionIsPreservedVerbatim() {
        for ext in ["mp4", "mov", "mxf", "MOV"] {
            let fileName = "SOMOS-9x16-v3-DE.\(ext)"
            let result = FileNameParser.parse(fileName)

            guard case .parsed(let parsed) = result.outcome else {
                return XCTFail("Erwartete .parsed für \(fileName), bekam \(result.outcome)")
            }
            XCTAssertEqual(parsed.fileExtension, ext)
            XCTAssertEqual(parsed.targetFileName, "SOMOS-4x5-v3-DE.\(ext)")
        }
    }

    // MARK: - Skip

    func testAlreadyTargetFormatIsSkipped() {
        let result = FileNameParser.parse("SOMOS-4x5-v3-DE.mp4")

        XCTAssertEqual(result.outcome, .skipped(.alreadyTargetFormat))
    }

    // MARK: - Rejection

    func testMissingFormatSegmentIsRejected() {
        let result = FileNameParser.parse("SOMOS-v3-DE.mp4")

        XCTAssertEqual(result.outcome, .rejected(.formatSegmentMissing))
    }

    func testFinderDuplicateIsRejected() {
        let result = FileNameParser.parse("SOMOS-9x16-v3-DE (1).mp4")

        XCTAssertEqual(result.outcome, .rejected(.finderDuplicate))
    }

    func testFinderDuplicateTakesPriorityOverMissingFormatSegment() {
        // Beide Aussagen wären technisch wahr; die handlungsleitende
        // Meldung (falsche Kopie erwischt) muss gewinnen.
        let result = FileNameParser.parse("SOMOS-v3-DE (1).mp4")

        XCTAssertEqual(result.outcome, .rejected(.finderDuplicate))
    }

    // MARK: - a) Rechtestes Vorkommen gewinnt

    func testRightmostFormatOccurrenceWins() {
        let result = FileNameParser.parse("Kampagne-9x16-Teaser-9x16-v3-DE.mp4")

        guard case .parsed(let parsed) = result.outcome else {
            return XCTFail("Erwartete .parsed, bekam \(result.outcome)")
        }
        XCTAssertEqual(parsed.projectName, "Kampagne-9x16-Teaser")
        XCTAssertEqual(parsed.remainder, "v3-DE")
        XCTAssertEqual(parsed.targetFileName, "Kampagne-9x16-Teaser-4x5-v3-DE.mp4")
    }

    func testRightmostAlreadyTargetFormatOccurrenceWins() {
        let result = FileNameParser.parse("Kampagne-4x5-Teaser-4x5-v3-DE.mp4")

        XCTAssertEqual(result.outcome, .skipped(.alreadyTargetFormat))
    }

    // MARK: - b) Projekt und Rest müssen existieren

    func testRejectsWhenNoProjectSegment() {
        let result = FileNameParser.parse("9x16-v3-DE.mp4")

        XCTAssertEqual(result.outcome, .rejected(.formatSegmentMissing))
    }

    func testParsesWithoutRemainderSegment() {
        let result = FileNameParser.parse("SOMOS-9x16.mp4")

        guard case .parsed(let parsed) = result.outcome else {
            return XCTFail("Erwartete .parsed, bekam \(result.outcome)")
        }
        XCTAssertEqual(parsed.projectName, "SOMOS")
        XCTAssertEqual(parsed.remainder, "")
        XCTAssertEqual(parsed.targetFileName, "SOMOS-4x5.mp4")
    }

    // MARK: - d) Lockere Schreibweisen

    func testUnderscoreAndSpaceSeparatorsArePreserved() {
        let cases = [
            ("SOMOS_9x16_v3_DE.mp4", "SOMOS", "v3_DE", "SOMOS_4x5_v3_DE.mp4"),
            ("SOMOS 9x16 v3 DE.mov", "SOMOS", "v3 DE", "SOMOS 4x5 v3 DE.mov"),
            ("Somos Pendant - 9X16_v3-DE.mp4", "Somos Pendant", "v3-DE", "Somos Pendant - 4x5_v3-DE.mp4"),
            ("SOMOS-9×16-v3.mp4", "SOMOS", "v3", "SOMOS-4x5-v3.mp4"),
            ("SOMOS (9 x 16) v3.mp4", "SOMOS", "v3", "SOMOS (4x5) v3.mp4")
        ]
        for (fileName, project, remainder, target) in cases {
            guard case .parsed(let parsed) = FileNameParser.parse(fileName).outcome else {
                XCTFail("Erwartete .parsed für \(fileName)")
                continue
            }
            XCTAssertEqual(parsed.projectName, project, fileName)
            XCTAssertEqual(parsed.remainder, remainder, fileName)
            XCTAssertEqual(parsed.targetFileName, target, fileName)
        }
    }

    func testTokenInsideWordIsNotAFormat() {
        XCTAssertEqual(FileNameParser.parse("SOMOS-19x160-v3.mp4").outcome, .rejected(.formatSegmentMissing))
        XCTAssertEqual(FileNameParser.parse("SOMOSx9x16v3.mp4").outcome, .rejected(.formatSegmentMissing))
    }

    func testTargetFormatInAnySpellingIsSkipped() {
        for fileName in ["SOMOS_4X5_v3.mp4", "SOMOS 4x5.mp4", "SOMOS-4×5-v3-DE.mp4"] {
            XCTAssertEqual(FileNameParser.parse(fileName).outcome, .skipped(.alreadyTargetFormat), fileName)
        }
    }

    // MARK: - e) Format anhängen, wenn es fehlt

    func testAppendingFormatUsesWholeStemAsProject() {
        let parsed = FileNameParser.appendingTargetFormat(to: "Sommerfest Teaser.mov")

        XCTAssertEqual(parsed?.projectName, "Sommerfest Teaser")
        XCTAssertEqual(parsed?.targetFileName, "Sommerfest Teaser 4x5.mov")
        XCTAssertEqual(parsed?.originalFileName, "Sommerfest Teaser.mov")
    }

    func testAppendingFormatPicksSeparatorFromName() {
        XCTAssertEqual(FileNameParser.appendingTargetFormat(to: "SOMOS-v3-DE.mp4")?.targetFileName, "SOMOS-v3-DE-4x5.mp4")
        XCTAssertEqual(FileNameParser.appendingTargetFormat(to: "SOMOS_v3.mp4")?.targetFileName, "SOMOS_v3_4x5.mp4")
        XCTAssertEqual(FileNameParser.appendingTargetFormat(to: "SOMOS.mp4")?.targetFileName, "SOMOS-4x5.mp4")
    }

    func testAppendingFormatOnlyForMissingFormat() {
        XCTAssertNil(FileNameParser.appendingTargetFormat(to: "SOMOS-9x16-v3-DE.mp4"))
        XCTAssertNil(FileNameParser.appendingTargetFormat(to: "SOMOS-4x5-v3-DE.mp4"))
        XCTAssertNil(FileNameParser.appendingTargetFormat(to: "SOMOS-v3-DE (1).mp4"))
    }

    // MARK: - c) Format-Segment in der Ausgabe immer klein geschrieben

    func testTargetFormatTokenIsAlwaysLowercase() {
        let result = FileNameParser.parse("SOMOS-9X16-v3-DE.mp4")

        guard case .parsed(let parsed) = result.outcome else {
            return XCTFail("Erwartete .parsed, bekam \(result.outcome)")
        }
        XCTAssertEqual(parsed.sourceFormatToken, "9X16")
        XCTAssertTrue(parsed.targetFileName.contains("-4x5-"))
        XCTAssertFalse(parsed.targetFileName.contains("4X16"))
        XCTAssertEqual(parsed.targetFileName, "SOMOS-4x5-v3-DE.mp4")
    }
}