import Foundation
import Testing
@testable import Music

struct SmartPlaylistTests {
    // Creates a SmartPlaylist in memory and verifies its properties.
    @Test func smartPlaylistProperties() throws {
        let sp = SmartPlaylist(
            id: nil,
            name: "Miles Davis",
            searchQuery: "miles davis",
            createdAt: Date(),
            conditions: nil
        )
        #expect(sp.name == "Miles Davis")
        #expect(sp.searchQuery == "miles davis")
        #expect(sp.isSmartPlaylist == true)
    }

    // Creates a smart playlist in the database and fetches it back.
    @Test func createAndFetchSmartPlaylist() throws {
        let db = try DatabaseService(inMemory: true)
        let sp = try db.createSmartPlaylist(name: "Jazz Vibes", searchQuery: "jazz")

        #expect(sp.id != nil)
        #expect(sp.name == "Jazz Vibes")
        #expect(sp.searchQuery == "jazz")

        let all = try db.fetchSmartPlaylists()
        #expect(all.count == 1)
        #expect(all[0].name == "Jazz Vibes")
    }

    // Renames a smart playlist and verifies the new name persists.
    @Test func renameSmartPlaylist() throws {
        let db = try DatabaseService(inMemory: true)
        let sp = try db.createSmartPlaylist(name: "Old Name", searchQuery: "old")
        try db.renameSmartPlaylist(id: sp.id!, name: "New Name")

        let all = try db.fetchSmartPlaylists()
        #expect(all[0].name == "New Name")
    }

    // Updates the search query of a smart playlist.
    @Test func updateSmartPlaylistQuery() throws {
        let db = try DatabaseService(inMemory: true)
        let sp = try db.createSmartPlaylist(name: "Jazz", searchQuery: "jazz")
        try db.updateSmartPlaylistQuery(id: sp.id!, searchQuery: "jazz fusion")

        let all = try db.fetchSmartPlaylists()
        #expect(all[0].searchQuery == "jazz fusion")
    }

    // Deletes a smart playlist and verifies it's gone.
    @Test func deleteSmartPlaylist() throws {
        let db = try DatabaseService(inMemory: true)
        let sp = try db.createSmartPlaylist(name: "To Delete", searchQuery: "delete")
        try db.deleteSmartPlaylist(id: sp.id!)

        let all = try db.fetchSmartPlaylists()
        #expect(all.isEmpty)
    }

    // Verifies smart playlist tracks are computed via FTS5 search (not stored).
    @Test func smartPlaylistReturnsDynamicResults() throws {
        let db = try DatabaseService(inMemory: true)
        var t1 = Track.fixture(fileURL: "/a.mp3", title: "Kind of Blue", artist: "Miles Davis")
        var t2 = Track.fixture(fileURL: "/b.mp3", title: "Hotel California", artist: "Eagles")
        var t3 = Track.fixture(fileURL: "/c.mp3", title: "Bitches Brew", artist: "Miles Davis")
        try db.insert(&t1)
        try db.insert(&t2)
        try db.insert(&t3)

        // Smart playlist uses the existing fetchTracks with its searchQuery
        let results = try db.fetchTracks(search: "miles davis", sortColumn: "title", ascending: true)
        #expect(results.count == 2)
        #expect(results[0].title == "Bitches Brew")
        #expect(results[1].title == "Kind of Blue")
    }

    // Creates a SmartPlaylist fixture with conditions and verifies the conditions
    // field is preserved and the isSmartPlaylist flag is true.
    @Test func smartPlaylistWithConditions() throws {
        let conditions = [SmartPlaylistCondition(field: .artist, op: .equals, value: .string("Miles Davis"))]
        let sp = SmartPlaylist.fixture(conditions: conditions)
        #expect(sp.conditions?.count == 1)
        #expect(sp.conditions?[0].field == .artist)
        #expect(sp.isSmartPlaylist == true)
    }

    // Encodes and decodes a SmartPlaylistCondition to/from JSON,
    // verifying that all fields survive the round-trip.
    @Test func conditionCodableRoundTrip() throws {
        let condition = SmartPlaylistCondition(
            field: .artist,
            op: .equals,
            value: .string("Miles Davis")
        )
        let data = try JSONEncoder().encode(condition)
        let decoded = try JSONDecoder().decode(SmartPlaylistCondition.self, from: data)
        #expect(decoded.field == .artist)
        #expect(decoded.op == .equals)
        if case .string(let s) = decoded.value {
            #expect(s == "Miles Davis")
        } else {
            Issue.record("Expected string value")
        }
    }

    // Encodes and decodes an array of conditions with mixed value types.
    @Test func conditionsArrayCodableRoundTrip() throws {
        let conditions: [SmartPlaylistCondition] = [
            SmartPlaylistCondition(field: .artist, op: .startsWith, value: .string("Miles")),
            SmartPlaylistCondition(field: .year, op: .greaterThan, value: .int(1960)),
            SmartPlaylistCondition(field: .dateAdded, op: .lessThan, value: .date(Date(timeIntervalSince1970: 0)))
        ]
        let data = try JSONEncoder().encode(conditions)
        let decoded = try JSONDecoder().decode([SmartPlaylistCondition].self, from: data)
        #expect(decoded.count == 3)
        #expect(decoded[0].field == .artist)
        #expect(decoded[1].op == .greaterThan)
        if case .int(let y) = decoded[1].value { #expect(y == 1960) } else { Issue.record("Expected int") }
        if case .date(let d) = decoded[2].value { #expect(d == Date(timeIntervalSince1970: 0)) } else { Issue.record("Expected date") }
    }

    // Creates an in-memory DB (which runs all migrations including v5) and verifies
    // that existing FTS smart playlists (conditions = nil) still load correctly.
    @Test func existingFTSPlaylistSurvivesMigration() throws {
        // Step 1: Create DB — migration v5 runs automatically, adding the conditions column
        // Step 2: Create a FTS smart playlist using the old searchQuery path
        // Step 3: Fetch it back and verify conditions is nil, searchQuery is intact
        let db = try DatabaseService(inMemory: true)
        _ = try db.createSmartPlaylist(name: "Jazz", searchQuery: "jazz")
        let all = try db.fetchSmartPlaylists()
        #expect(all.count == 1)
        #expect(all[0].searchQuery == "jazz")
        #expect(all[0].conditions == nil)
    }

    // Inserts two tracks with different artists, fetches with an equals condition
    // on artist, and verifies only the matching track is returned.
    @Test func fetchTracksWithEqualsCondition() throws {
        // Step 1: Insert two tracks with different artists
        // Step 2: Build a condition: artist equals "Miles Davis"
        // Step 3: Fetch tracks with that condition and verify only one returned
        let db = try DatabaseService(inMemory: true)
        var t1 = Track.fixture(fileURL: "/a.mp3", title: "Kind of Blue", artist: "Miles Davis")
        var t2 = Track.fixture(fileURL: "/b.mp3", title: "Hotel California", artist: "Eagles")
        try db.insert(&t1)
        try db.insert(&t2)
        let conditions = [SmartPlaylistCondition(field: .artist, op: .equals, value: .string("Miles Davis"))]
        let results = try db.fetchTracks(conditions: conditions, sortColumn: "title", ascending: true)
        #expect(results.count == 1)
        #expect(results[0].artist == "Miles Davis")
    }

    // Verifies that string equals matching is case-insensitive.
    @Test func fetchTracksEqualsIsCaseInsensitive() throws {
        // Step 1: Insert a track with mixed-case artist "Miles Davis"
        // Step 2: Fetch using lowercase "miles davis"
        // Step 3: Verify the track is returned
        let db = try DatabaseService(inMemory: true)
        var t = Track.fixture(fileURL: "/a.mp3", artist: "Miles Davis")
        try db.insert(&t)
        let conditions = [SmartPlaylistCondition(field: .artist, op: .equals, value: .string("miles davis"))]
        let results = try db.fetchTracks(conditions: conditions, sortColumn: "title", ascending: true)
        #expect(results.count == 1)
    }

    // Verifies that startsWith matches case-insensitively on the leading prefix.
    @Test func fetchTracksWithStartsWithCondition() throws {
        // Step 1: Insert a Miles Davis track and an Eagles track
        // Step 2: Fetch with artist startsWith "miles" (lowercase)
        // Step 3: Verify only Miles Davis is returned
        let db = try DatabaseService(inMemory: true)
        var t1 = Track.fixture(fileURL: "/a.mp3", artist: "Miles Davis")
        var t2 = Track.fixture(fileURL: "/b.mp3", artist: "Eagles")
        try db.insert(&t1)
        try db.insert(&t2)
        let conditions = [SmartPlaylistCondition(field: .artist, op: .startsWith, value: .string("miles"))]
        let results = try db.fetchTracks(conditions: conditions, sortColumn: "title", ascending: true)
        #expect(results.count == 1)
        #expect(results[0].artist == "Miles Davis")
    }

    // Verifies that greaterThan on an integer field returns only tracks strictly
    // above the threshold value.
    @Test func fetchTracksWithGreaterThanCondition() throws {
        // Step 1: Insert tracks with years 1990, 2010, 2020
        // Step 2: Fetch with year > 2000
        // Step 3: Verify 2010 and 2020 are returned; 1990 is not
        let db = try DatabaseService(inMemory: true)
        var t1 = Track.fixture(fileURL: "/a.mp3", year: 1990)
        var t2 = Track.fixture(fileURL: "/b.mp3", year: 2010)
        var t3 = Track.fixture(fileURL: "/c.mp3", year: 2020)
        try db.insert(&t1)
        try db.insert(&t2)
        try db.insert(&t3)
        let conditions = [SmartPlaylistCondition(field: .year, op: .greaterThan, value: .int(2000))]
        let results = try db.fetchTracks(conditions: conditions, sortColumn: "title", ascending: true)
        #expect(results.count == 2)
        #expect(results.allSatisfy { ($0.year ?? 0) > 2000 })
    }

    // Verifies that multiple conditions are AND-ed: only tracks matching all
    // conditions are returned.
    @Test func fetchTracksWithMultipleAndConditions() throws {
        // Step 1: Insert three tracks — two Miles Davis (1959, 1970) and one Eagles (1975)
        // Step 2: Fetch with artist = "Miles Davis" AND year > 1960
        // Step 3: Verify only the 1970 Miles Davis track is returned
        let db = try DatabaseService(inMemory: true)
        var t1 = Track.fixture(fileURL: "/a.mp3", title: "Kind of Blue", artist: "Miles Davis", year: 1959)
        var t2 = Track.fixture(fileURL: "/b.mp3", title: "Bitches Brew", artist: "Miles Davis", year: 1970)
        var t3 = Track.fixture(fileURL: "/c.mp3", title: "Hotel California", artist: "Eagles", year: 1975)
        try db.insert(&t1)
        try db.insert(&t2)
        try db.insert(&t3)
        let conditions = [
            SmartPlaylistCondition(field: .artist, op: .equals, value: .string("Miles Davis")),
            SmartPlaylistCondition(field: .year, op: .greaterThan, value: .int(1960))
        ]
        let results = try db.fetchTracks(conditions: conditions, sortColumn: "title", ascending: true)
        #expect(results.count == 1)
        #expect(results[0].title == "Bitches Brew")
    }

    // Creates a conditions-based smart playlist, fetches it back, and verifies the
    // conditions survive the JSON round-trip through GRDB's Codable synthesis.
    @Test func createSmartPlaylistWithConditionsPersists() throws {
        // Step 1: Create a conditions-based playlist with artist equals and year > conditions
        // Step 2: Fetch all smart playlists
        // Step 3: Verify both conditions survived the DB round-trip intact
        let db = try DatabaseService(inMemory: true)
        let conditions = [
            SmartPlaylistCondition(field: .artist, op: .equals, value: .string("Miles Davis")),
            SmartPlaylistCondition(field: .year, op: .greaterThan, value: .int(1960))
        ]
        _ = try db.createSmartPlaylist(name: "Late Miles", conditions: conditions)
        let all = try db.fetchSmartPlaylists()
        #expect(all.count == 1)
        #expect(all[0].conditions?.count == 2)
        #expect(all[0].conditions?[0].field == .artist)
        #expect(all[0].conditions?[1].op == .greaterThan)
        if case .int(let y) = all[0].conditions?[1].value {
            #expect(y == 1960)
        } else {
            Issue.record("Expected int value")
        }
    }

    // Verifies that lessThan on an integer field returns only tracks strictly
    // below the threshold value.
    @Test func fetchTracksWithLessThanCondition() throws {
        // Step 1: Insert tracks with years 1990, 2010, 2020
        // Step 2: Fetch with year < 2000
        // Step 3: Verify only the 1990 track is returned
        let db = try DatabaseService(inMemory: true)
        var t1 = Track.fixture(fileURL: "/a.mp3", year: 1990)
        var t2 = Track.fixture(fileURL: "/b.mp3", year: 2010)
        var t3 = Track.fixture(fileURL: "/c.mp3", year: 2020)
        try db.insert(&t1)
        try db.insert(&t2)
        try db.insert(&t3)
        let conditions = [SmartPlaylistCondition(field: .year, op: .lessThan, value: .int(2000))]
        let results = try db.fetchTracks(conditions: conditions, sortColumn: "title", ascending: true)
        #expect(results.count == 1)
        #expect((results[0].year ?? 0) < 2000)
    }

    // Verifies that the startsWith operator treats % and _ as literal characters,
    // not LIKE wildcards — confirming the ESCAPE clause in buildWhereClause works.
    @Test func startsWithEscapesLIKEMetachars() throws {
        // Step 1: Insert a track whose artist literally contains "%" and one whose
        //         artist matches the % wildcard pattern but not the literal prefix
        // Step 2: Search with startsWith "A%B" — only the literal match should return
        // Step 3: Verify only the literal "A%B Band" track is returned, not "AXB Band"
        let db = try DatabaseService(inMemory: true)
        var t1 = Track.fixture(fileURL: "/a.mp3", artist: "A%B Band")
        var t2 = Track.fixture(fileURL: "/b.mp3", artist: "AXB Band")
        try db.insert(&t1)
        try db.insert(&t2)
        let conditions = [SmartPlaylistCondition(field: .artist, op: .startsWith, value: .string("A%B"))]
        let results = try db.fetchTracks(conditions: conditions, sortColumn: "title", ascending: true)
        #expect(results.count == 1)
        #expect(results[0].artist == "A%B Band")
    }

    // Updates the conditions of a structured smart playlist and verifies the updated
    // conditions are persisted and fetch back correctly.
    @Test func updateSmartPlaylistConditionsPersists() throws {
        // Step 1: Create a playlist with artist = "Eagles"
        // Step 2: Update its conditions to genre startsWith "Jazz"
        // Step 3: Fetch and verify the updated conditions are stored
        let db = try DatabaseService(inMemory: true)
        let sp = try db.createSmartPlaylist(
            name: "Test",
            conditions: [SmartPlaylistCondition(field: .artist, op: .equals, value: .string("Eagles"))]
        )
        let newConditions = [SmartPlaylistCondition(field: .genre, op: .startsWith, value: .string("Jazz"))]
        try db.updateSmartPlaylistConditions(id: sp.id!, conditions: newConditions)
        let all = try db.fetchSmartPlaylists()
        #expect(all[0].conditions?.count == 1)
        #expect(all[0].conditions?[0].field == .genre)
    }
}