//
//  StubDataProvider.swift
//  SportsTime
//
//  Provides real data from bundled JSON files for Simulator testing
//

import Foundation
import CryptoKit

actor StubDataProvider: DataProvider {

    // MARK: - JSON Models

    private struct JSONGame: Codable {
        let id: String
        let sport: String
        let season: String
        let date: String
        let time: String?
        let home_team: String
        let away_team: String
        let home_team_abbrev: String
        let away_team_abbrev: String
        let venue: String
        let source: String
        let is_playoff: Bool
        let broadcast: String?
    }

    private struct JSONStadium: Codable {
        let id: String
        let name: String
        let city: String
        let state: String
        let latitude: Double
        let longitude: Double
        let capacity: Int
        let sport: String
        let team_abbrevs: [String]
        let source: String
        let year_opened: Int?
    }

    // MARK: - Cached Data

    private var cachedGames: [Game]?
    private var cachedTeams: [Team]?
    private var cachedStadiums: [Stadium]?
    private var teamsByAbbrev: [String: Team] = [:]
    private var stadiumsByVenue: [String: Stadium] = [:]

    // MARK: - DataProvider Protocol

    func fetchTeams(for sport: Sport) async throws -> [Team] {
        try await loadAllDataIfNeeded()
        return cachedTeams?.filter { $0.sport == sport } ?? []
    }

    func fetchAllTeams() async throws -> [Team] {
        try await loadAllDataIfNeeded()
        return cachedTeams ?? []
    }

    func fetchStadiums() async throws -> [Stadium] {
        try await loadAllDataIfNeeded()
        return cachedStadiums ?? []
    }

    func fetchGames(sports: Set<Sport>, startDate: Date, endDate: Date) async throws -> [Game] {
        try await loadAllDataIfNeeded()

        return (cachedGames ?? []).filter { game in
            sports.contains(game.sport) &&
            game.dateTime >= startDate &&
            game.dateTime <= endDate
        }
    }

    func fetchGame(by id: UUID) async throws -> Game? {
        try await loadAllDataIfNeeded()
        return cachedGames?.first { $0.id == id }
    }

    func fetchRichGames(sports: Set<Sport>, startDate: Date, endDate: Date) async throws -> [RichGame] {
        try await loadAllDataIfNeeded()

        let games = try await fetchGames(sports: sports, startDate: startDate, endDate: endDate)
        let teamsById = Dictionary(uniqueKeysWithValues: (cachedTeams ?? []).map { ($0.id, $0) })
        let stadiumsById = Dictionary(uniqueKeysWithValues: (cachedStadiums ?? []).map { ($0.id, $0) })

        return games.compactMap { game in
            guard let homeTeam = teamsById[game.homeTeamId],
                  let awayTeam = teamsById[game.awayTeamId],
                  let stadium = stadiumsById[game.stadiumId] else {
                return nil
            }
            return RichGame(game: game, homeTeam: homeTeam, awayTeam: awayTeam, stadium: stadium)
        }
    }

    // MARK: - Data Loading

    private func loadAllDataIfNeeded() async throws {
        guard cachedGames == nil else { return }

        // Load stadiums first
        let jsonStadiums = try loadStadiumsJSON()
        cachedStadiums = jsonStadiums.map { convertStadium($0) }

        // Build stadium lookup by venue name
        for stadium in cachedStadiums ?? [] {
            stadiumsByVenue[stadium.name.lowercased()] = stadium
        }

        // Load games and extract teams
        let jsonGames = try loadGamesJSON()

        // Build teams from games data
        var teamsDict: [String: Team] = [:]
        for jsonGame in jsonGames {
            let sport = parseSport(jsonGame.sport)

            // Home team
            let homeKey = "\(sport.rawValue)_\(jsonGame.home_team_abbrev)"
            if teamsDict[homeKey] == nil {
                let stadiumId = findStadiumId(venue: jsonGame.venue, sport: sport)
                let team = Team(
                    id: deterministicUUID(from: homeKey),
                    name: extractTeamName(from: jsonGame.home_team),
                    abbreviation: jsonGame.home_team_abbrev,
                    sport: sport,
                    city: extractCity(from: jsonGame.home_team),
                    stadiumId: stadiumId
                )
                teamsDict[homeKey] = team
                teamsByAbbrev[homeKey] = team
            }

            // Away team
            let awayKey = "\(sport.rawValue)_\(jsonGame.away_team_abbrev)"
            if teamsDict[awayKey] == nil {
                // Away teams might not have a stadium in our data yet
                let team = Team(
                    id: deterministicUUID(from: awayKey),
                    name: extractTeamName(from: jsonGame.away_team),
                    abbreviation: jsonGame.away_team_abbrev,
                    sport: sport,
                    city: extractCity(from: jsonGame.away_team),
                    stadiumId: UUID() // Placeholder, will be updated when they're home team
                )
                teamsDict[awayKey] = team
                teamsByAbbrev[awayKey] = team
            }
        }
        cachedTeams = Array(teamsDict.values)

        // Convert games (deduplicate by ID - JSON may have duplicate entries)
        var seenGameIds = Set<String>()
        let uniqueJsonGames = jsonGames.filter { game in
            if seenGameIds.contains(game.id) {
                return false
            }
            seenGameIds.insert(game.id)
            return true
        }
        cachedGames = uniqueJsonGames.compactMap { convertGame($0) }

        print("StubDataProvider loaded: \(cachedGames?.count ?? 0) games, \(cachedTeams?.count ?? 0) teams, \(cachedStadiums?.count ?? 0) stadiums")
    }

    private func loadGamesJSON() throws -> [JSONGame] {
        guard let url = Bundle.main.url(forResource: "games", withExtension: "json") else {
            print("Warning: games.json not found in bundle")
            return []
        }
        let data = try Data(contentsOf: url)
        do {
            return try JSONDecoder().decode([JSONGame].self, from: data)
        } catch let DecodingError.keyNotFound(key, context) {
            print("❌ Games JSON missing key '\(key.stringValue)' at path: \(context.codingPath.map { $0.stringValue }.joined(separator: "."))")
            throw DecodingError.keyNotFound(key, context)
        } catch let DecodingError.typeMismatch(type, context) {
            print("❌ Games JSON type mismatch for \(type) at path: \(context.codingPath.map { $0.stringValue }.joined(separator: "."))")
            throw DecodingError.typeMismatch(type, context)
        } catch {
            print("❌ Games JSON decode error: \(error)")
            throw error
        }
    }

    private func loadStadiumsJSON() throws -> [JSONStadium] {
        guard let url = Bundle.main.url(forResource: "stadiums", withExtension: "json") else {
            print("Warning: stadiums.json not found in bundle")
            return []
        }
        let data = try Data(contentsOf: url)
        do {
            return try JSONDecoder().decode([JSONStadium].self, from: data)
        } catch let DecodingError.keyNotFound(key, context) {
            print("❌ Stadiums JSON missing key '\(key.stringValue)' at path: \(context.codingPath.map { $0.stringValue }.joined(separator: "."))")
            throw DecodingError.keyNotFound(key, context)
        } catch let DecodingError.typeMismatch(type, context) {
            print("❌ Stadiums JSON type mismatch for \(type) at path: \(context.codingPath.map { $0.stringValue }.joined(separator: "."))")
            throw DecodingError.typeMismatch(type, context)
        } catch {
            print("❌ Stadiums JSON decode error: \(error)")
            throw error
        }
    }

    // MARK: - Conversion Helpers

    private func convertStadium(_ json: JSONStadium) -> Stadium {
        Stadium(
            id: deterministicUUID(from: json.id),
            name: json.name,
            city: json.city,
            state: json.state.isEmpty ? stateFromCity(json.city) : json.state,
            latitude: json.latitude,
            longitude: json.longitude,
            capacity: json.capacity,
            yearOpened: json.year_opened
        )
    }

    private func convertGame(_ json: JSONGame) -> Game? {
        let sport = parseSport(json.sport)

        let homeKey = "\(sport.rawValue)_\(json.home_team_abbrev)"
        let awayKey = "\(sport.rawValue)_\(json.away_team_abbrev)"

        guard let homeTeam = teamsByAbbrev[homeKey],
              let awayTeam = teamsByAbbrev[awayKey] else {
            return nil
        }

        let stadiumId = findStadiumId(venue: json.venue, sport: sport)

        guard let dateTime = parseDateTime(date: json.date, time: json.time ?? "7:00p") else {
            return nil
        }

        return Game(
            id: deterministicUUID(from: json.id),
            homeTeamId: homeTeam.id,
            awayTeamId: awayTeam.id,
            stadiumId: stadiumId,
            dateTime: dateTime,
            sport: sport,
            season: json.season,
            isPlayoff: json.is_playoff,
            broadcastInfo: json.broadcast
        )
    }

    private func parseSport(_ sport: String) -> Sport {
        switch sport.uppercased() {
        case "MLB": return .mlb
        case "NBA": return .nba
        case "NHL": return .nhl
        case "NFL": return .nfl
        case "MLS": return .mls
        default: return .mlb
        }
    }

    private func parseDateTime(date: String, time: String) -> Date? {
        let formatter = DateFormatter()
        formatter.locale = Locale(identifier: "en_US_POSIX")

        // Parse date
        formatter.dateFormat = "yyyy-MM-dd"
        guard let dateOnly = formatter.date(from: date) else { return nil }

        // Parse time (e.g., "7:30p", "10:00p", "1:05p")
        var hour = 12
        var minute = 0

        let cleanTime = time.lowercased().replacingOccurrences(of: " ", with: "")
        let isPM = cleanTime.contains("p")
        let timeWithoutAMPM = cleanTime.replacingOccurrences(of: "p", with: "").replacingOccurrences(of: "a", with: "")

        let components = timeWithoutAMPM.split(separator: ":")
        if !components.isEmpty, let h = Int(components[0]) {
            hour = h
            if isPM && hour != 12 {
                hour += 12
            } else if !isPM && hour == 12 {
                hour = 0
            }
        }
        if components.count > 1, let m = Int(components[1]) {
            minute = m
        }

        return Calendar.current.date(bySettingHour: hour, minute: minute, second: 0, of: dateOnly)
    }

    // Venue name aliases for stadiums that changed names
    private static let venueAliases: [String: String] = [
        "daikin park": "minute maid park",                    // Houston Astros (renamed 2024)
        "rate field": "guaranteed rate field",                // Chicago White Sox
        "george m. steinbrenner field": "tropicana field",    // Tampa Bay spring training → main stadium
        "loandepot park": "loandepot park",                   // Miami - ensure case match
    ]

    private func findStadiumId(venue: String, sport: Sport) -> UUID {
        var venueLower = venue.lowercased()

        // Check for known aliases
        if let aliasedName = Self.venueAliases[venueLower] {
            venueLower = aliasedName
        }

        // Try exact match
        if let stadium = stadiumsByVenue[venueLower] {
            return stadium.id
        }

        // Try partial match
        for (name, stadium) in stadiumsByVenue {
            if name.contains(venueLower) || venueLower.contains(name) {
                return stadium.id
            }
        }

        // Generate deterministic ID for unknown venues
        print("[StubDataProvider] No stadium match for venue: '\(venue)'")
        return deterministicUUID(from: "venue_\(venue)")
    }

    private func deterministicUUID(from string: String) -> UUID {
        // Create a deterministic UUID using SHA256 (truly deterministic across launches)
        let data = Data(string.utf8)
        let hash = SHA256.hash(data: data)
        let hashBytes = Array(hash)

        // Use first 16 bytes of SHA256 hash
        var bytes = Array(hashBytes.prefix(16))

        // Set UUID version (4) and variant bits
        bytes[6] = (bytes[6] & 0x0F) | 0x40
        bytes[8] = (bytes[8] & 0x3F) | 0x80

        return UUID(uuid: (
            bytes[0], bytes[1], bytes[2], bytes[3],
            bytes[4], bytes[5], bytes[6], bytes[7],
            bytes[8], bytes[9], bytes[10], bytes[11],
            bytes[12], bytes[13], bytes[14], bytes[15]
        ))
    }

    private func extractTeamName(from fullName: String) -> String {
        // "Boston Celtics" -> "Celtics"
        let parts = fullName.split(separator: " ")
        if parts.count > 1 {
            return parts.dropFirst().joined(separator: " ")
        }
        return fullName
    }

    private func extractCity(from fullName: String) -> String {
        // "Boston Celtics" -> "Boston"
        // "New York Knicks" -> "New York"
        // "Los Angeles Lakers" -> "Los Angeles"
        let knownCities = [
            "New York", "Los Angeles", "San Francisco", "San Diego", "San Antonio",
            "New Orleans", "Oklahoma City", "Salt Lake City", "Kansas City",
            "St. Louis", "St Louis"
        ]

        for city in knownCities {
            if fullName.hasPrefix(city) {
                return city
            }
        }

        // Default: first word
        return String(fullName.split(separator: " ").first ?? Substring(fullName))
    }

    private func stateFromCity(_ city: String) -> String {
        let cityToState: [String: String] = [
            "Atlanta": "GA", "Boston": "MA", "Brooklyn": "NY", "Charlotte": "NC",
            "Chicago": "IL", "Cleveland": "OH", "Dallas": "TX", "Denver": "CO",
            "Detroit": "MI", "Houston": "TX", "Indianapolis": "IN", "Los Angeles": "CA",
            "Memphis": "TN", "Miami": "FL", "Milwaukee": "WI", "Minneapolis": "MN",
            "New Orleans": "LA", "New York": "NY", "Oklahoma City": "OK", "Orlando": "FL",
            "Philadelphia": "PA", "Phoenix": "AZ", "Portland": "OR", "Sacramento": "CA",
            "San Antonio": "TX", "San Francisco": "CA", "Seattle": "WA", "Toronto": "ON",
            "Washington": "DC", "Las Vegas": "NV", "Tampa": "FL", "Pittsburgh": "PA",
            "Baltimore": "MD", "Cincinnati": "OH", "St. Louis": "MO", "Kansas City": "MO",
            "Arlington": "TX", "Anaheim": "CA", "Oakland": "CA", "San Diego": "CA",
            "Tampa Bay": "FL", "St Petersburg": "FL", "Salt Lake City": "UT"
        ]
        return cityToState[city] ?? ""
    }
}