//
// StarterGalleryView.swift
// Workouts
//
// Copyright 2026 Rouslan Zenetl. All Rights Reserved.
//

import SwiftUI
import SwiftData

/// Every bundled starter routine — including ones the user has deleted — with a
/// per-seed Add/Restore action and a bulk "re-add everything missing" fallback. Unlike
/// `RoutinesLibraryView` (which only ever shows *live* routines), this reads straight
/// from `SeedLibrary.seeds`, the bundle-derived source of truth, so a deleted starter
/// still has a row here. Pushed from that view's "Browse Starter Routines" entry.
struct StarterGalleryView: View {
    @Environment(SyncEngine.self) private var sync

    @Query(sort: [SortDescriptor(\Routine.order), SortDescriptor(\Routine.name)])
    private var routines: [Routine]

    @State private var isRestoringAll = false
    @State private var restoreAllMessage: String?

    var body: some View {
        List {
            Section {
                ForEach(SeedLibrary.seeds, id: \.id) { seed in
                    row(for: seed)
                }
            } footer: {
                Text("Every routine Workouts ships with, whether or not you've kept it. Adding one never touches a routine you've created or edited.")
            }

            Section {
                Button {
                    Task {
                        isRestoringAll = true
                        restoreAllMessage = nil
                        let n = await sync.restoreSeeds()
                        isRestoringAll = false
                        restoreAllMessage = n == 0
                            ? "All starter routines are already present."
                            : "Restored \(n) starter routine\(n == 1 ? "" : "s")."
                    }
                } label: {
                    HStack {
                        Label("Re-add All Missing Starters", systemImage: "arrow.counterclockwise")
                        if isRestoringAll {
                            Spacer()
                            ProgressView()
                        }
                    }
                }
                .disabled(isRestoringAll || sync.iCloudStatus != .available)
            } footer: {
                if let restoreAllMessage {
                    Text(restoreAllMessage)
                }
            }
        }
        .listStyle(.insetGrouped)
        .navigationTitle("Starter Routines")
        .navigationBarTitleDisplayMode(.inline)
    }

    // MARK: - Row

    /// One seed's row: always navigable (to the live detail once added, otherwise the
    /// read-only preview), with a state-appropriate trailing accessory — a checkmark
    /// once added, an inline Add button while restorable (a `.borderless` button style
    /// keeps its tap from also firing the row's `NavigationLink`), or nothing extra
    /// when blocked (the preview screen explains why).
    @ViewBuilder
    private func row(for seed: SeedLibrary.Seed) -> some View {
        switch seed.state(among: routines) {
        case .added(let routine):
            NavigationLink {
                RoutineDetailView(routine: routine)
            } label: {
                HStack {
                    content(for: seed.doc)
                    Spacer()
                    Image(systemName: "checkmark.circle.fill")
                        .foregroundStyle(.green)
                }
            }
        case .nameTaken:
            NavigationLink {
                StarterPreviewView(seed: seed)
            } label: {
                content(for: seed.doc, caption: "A routine named \"\(seed.doc.name)\" already exists")
            }
        case .restorable:
            NavigationLink {
                StarterPreviewView(seed: seed)
            } label: {
                HStack {
                    content(for: seed.doc)
                    Spacer()
                    Button("Add") {
                        Task { _ = await sync.restoreSeed(id: seed.id) }
                    }
                    .buttonStyle(.borderless)
                    .disabled(sync.iCloudStatus != .available)
                }
            }
        }
    }

    /// The row's icon badge + name + caption — the same visual language as
    /// `RoutinesLibraryView`'s `RoutineRow`, but built from the seed's `RoutineDocument`
    /// rather than a live `Routine` (a not-yet-added seed has no entity to read).
    /// `caption` overrides the default exercise count when the row needs to explain
    /// itself instead.
    private func content(for doc: RoutineDocument, caption: String? = nil) -> some View {
        HStack(spacing: 12) {
            Image(systemName: doc.systemImage)
                .font(.title3)
                .foregroundStyle(Color.color(from: doc.color))
                .frame(width: 36, height: 36)
                .background(Color.color(from: doc.color).opacity(0.12), in: RoundedRectangle(cornerRadius: 8))

            VStack(alignment: .leading, spacing: 2) {
                Text(doc.name)
                    .foregroundStyle(.primary)
                Text(caption ?? "\(doc.exercises.count) exercises")
                    .font(.caption)
                    .foregroundStyle(.secondary)
            }
        }
        .padding(.vertical, 2)
    }
}