import Foundation
import SwiftUI

// MARK: - Training Plan

struct TrainingPlan: Identifiable, Equatable, Codable {
    let id: String
    let title: String
    let description: String
    let planType: PlanType
    let durationWeeks: Int
    let difficulty: Difficulty
    let startDate: Date
    let endDate: Date
    let weeklyWorkouts: [WeeklyWorkout]
    var progress: PlanProgress
    var isFollowing: Bool
    let createdAt: Date

    enum CodingKeys: String, CodingKey {
        case id, title, description, planType, durationWeeks, difficulty, startDate, endDate, weeklyWorkouts, progress, isFollowing, createdAt
    }

    init(
        id: String,
        title: String,
        description: String,
        planType: PlanType,
        durationWeeks: Int,
        difficulty: Difficulty,
        startDate: Date,
        endDate: Date,
        weeklyWorkouts: [WeeklyWorkout],
        progress: PlanProgress,
        isFollowing: Bool,
        createdAt: Date
    ) {
        self.id = id
        self.title = title
        self.description = description
        self.planType = planType
        self.durationWeeks = durationWeeks
        self.difficulty = difficulty
        self.startDate = startDate
        self.endDate = endDate
        self.weeklyWorkouts = weeklyWorkouts
        self.progress = progress
        self.isFollowing = isFollowing
        self.createdAt = createdAt
    }

    static func == (lhs: TrainingPlan, rhs: TrainingPlan) -> Bool {
        lhs.id == rhs.id
    }
}

// MARK: - Plan Type

enum PlanType: String, CaseIterable, Codable {
    case fiveK = "5K"
    case tenK = "10K"
    case halfMarathon = "HALF_MARATHON"
    case fullMarathon = "FULL_MARATHON"
    case custom = "CUSTOM"

    var displayName: String {
        switch self {
        case .fiveK: return "5K"
        case .tenK: return "10K"
        case .halfMarathon: return "Half Marathon"
        case .fullMarathon: return "Full Marathon"
        case .custom: return "Custom"
        }
    }

    var distanceKm: Double {
        switch self {
        case .fiveK: return 5.0
        case .tenK: return 10.0
        case .halfMarathon: return 21.1
        case .fullMarathon: return 42.2
        case .custom: return 0.0
        }
    }

    var icon: String {
        switch self {
        case .fiveK: return "figure.run"
        case .tenK: return "figure.run"
        case .halfMarathon: return "flag.fill"
        case .fullMarathon: return "flag.fill"
        case .custom: return "wrench.and.screwdriver"
        }
    }
}

// MARK: - Difficulty

enum Difficulty: String, CaseIterable, Codable {
    case beginner
    case intermediate
    case advanced
    case elite

    var displayName: String {
        switch self {
        case .beginner: return "Beginner"
        case .intermediate: return "Intermediate"
        case .advanced: return "Advanced"
        case .elite: return "Elite"
        }
    }

    var color: Color {
        switch self {
        case .beginner: return .green
        case .intermediate: return .blue
        case .advanced: return .orange
        case .elite: return .red
        }
    }
}

// MARK: - Weekly Workout

struct WeeklyWorkout: Identifiable, Codable {
    let id: String
    let weekNumber: Int
    let dailySessions: [DailySession]

    var completedSessions: Int {
        dailySessions.filter { $0.status == .completed }.count
    }

    var totalSessions: Int {
        dailySessions.count
    }

    var progressPercentage: Double {
        totalSessions == 0 ? 0 : Double(completedSessions) / Double(totalSessions) * 100
    }
}

// MARK: - Daily Session

struct DailySession: Identifiable, Codable {
    let id: String
    let dayOfWeek: DayOfWeek
    let workoutType: WorkoutType
    let title: String
    let description: String
    let targetDistanceKm: Double?
    let targetDurationMinutes: Int?
    let targetPaceMinPerKm: Double?
    let intensity: Intensity
    var status: SessionStatus
    var completedDistanceKm: Double?
    var completedDurationMinutes: Int?

    enum CodingKeys: String, CodingKey {
        case id, dayOfWeek, workoutType, title, description, targetDistanceKm, targetDurationMinutes, targetPaceMinPerKm, intensity, status, completedDistanceKm, completedDurationMinutes
    }
}

// MARK: - Day of Week

enum DayOfWeek: String, CaseIterable, Codable {
    case monday, tuesday, wednesday, thursday, friday, saturday, sunday

    var displayName: String {
        switch self {
        case .monday: return "Mon"
        case .tuesday: return "Tue"
        case .wednesday: return "Wed"
        case .thursday: return "Thu"
        case .friday: return "Fri"
        case .saturday: return "Sat"
        case .sunday: return "Sun"
        }
    }
}

// MARK: - Workout Type

enum WorkoutType: String, CaseIterable, Codable {
    case easyRun
    case tempoRun
    case intervalTraining
    case longRun
    case speedWork
    case recoveryRun
    case crossTraining
    case rest

    var displayName: String {
        switch self {
        case .easyRun: return "Easy Run"
        case .tempoRun: return "Tempo Run"
        case .intervalTraining: return "Intervals"
        case .longRun: return "Long Run"
        case .speedWork: return "Speed Work"
        case .recoveryRun: return "Recovery Run"
        case .crossTraining: return "Cross Train"
        case .rest: return "Rest"
        }
    }

    var icon: String {
        switch self {
        case .easyRun: return "figure.walk"
        case .tempoRun: return "figure.run"
        case .intervalTraining: return "bolt.fill"
        case .longRun: return "figure.run"
        case .speedWork: return "speedometer"
        case .recoveryRun: return "leaf.fill"
        case .crossTraining: return "dumbbell.fill"
        case .rest: return "moon.fill"
        }
    }

    var color: Color {
        switch self {
        case .easyRun: return .green
        case .tempoRun: return .blue
        case .intervalTraining: return .purple
        case .longRun: return .orange
        case .speedWork: return .red
        case .recoveryRun: return .mint
        case .crossTraining: return .gray
        case .rest: return .secondary
        }
    }
}

// MARK: - Intensity

enum Intensity: String, CaseIterable, Codable {
    case veryEasy
    case easy
    case moderate
    case hard
    case veryHard

    var displayName: String {
        switch self {
        case .veryEasy: return "Very Easy"
        case .easy: return "Easy"
        case .moderate: return "Moderate"
        case .hard: return "Hard"
        case .veryHard: return "Very Hard"
        }
    }
}

// MARK: - Session Status

enum SessionStatus: String, CaseIterable, Codable {
    case pending
    case inProgress
    case completed
    case skipped
}

// MARK: - Plan Progress

struct PlanProgress: Codable {
    let completedWeeks: Int
    let totalWeeks: Int
    let completedSessions: Int
    let totalSessions: Int
    let currentWeekNumber: Int

    var percentage: Double {
        totalWeeks == 0 ? 0 : Double(completedWeeks) / Double(totalWeeks) * 100
    }

    var sessionPercentage: Double {
        totalSessions == 0 ? 0 : Double(completedSessions) / Double(totalSessions) * 100
    }
}

// MARK: - AI Plan Generation Request

struct GeneratePlanRequest: Encodable {
    let planType: PlanType
    let difficulty: Difficulty
    let startDate: Date
    let currentWeeklyMileageKm: Double?
    let goalTimeMinutes: Int?
    let availableDays: [DayOfWeek]
}

// MARK: - API Response Types

struct TrainingPlanListResponse: Decodable {
    let plans: [TrainingPlan]
    let hasMore: Bool
}

struct TrainingPlanDetailResponse: Decodable {
    let plan: TrainingPlan
}

struct GeneratePlanResponse: Decodable {
    let plan: TrainingPlan
}

struct UpdateSessionStatusResponse: Decodable {
    let success: Bool
    let sessionId: String
    let status: SessionStatus
}