// Auteur : Simon-Pierre Boucher — contact@spboucher.ai
// HomeView.swift — l'accueil VIVANT : salutation selon l'heure, suggestions
// contextuelles (restos le soir, sorties le week-end, emplois le matin…) avec
// du VRAI contenu en direct, et le pouls de l'écosystème (compteurs live).
import SwiftUI

struct HomeView: View {
    @State private var featured: [(universe: Universe, items: [KAItem])] = []
    @State private var pulse: [(Universe, Int)] = []
    @State private var loading = true
    @AppStorage("ka.favUniverses") private var favUniversesRaw = ""
    @EnvironmentObject private var favorites: FavoritesStore
    @EnvironmentObject private var recents: RecentsStore
    @State private var editorialItems: [String: [KAItem]] = [:]
    @Environment(\.colorScheme) private var scheme

    var body: some View {
        NavigationStack {
            ScrollView {
                VStack(alignment: .leading, spacing: 22) {
                    header
                    pulseStrip
                    resumeStrip
                    ForEach(featured, id: \.universe.id) { section in
                        featuredSection(section.universe, section.items)
                    }
                    editorialSection
                    if loading && featured.isEmpty {
                        ProgressView("KA prépare votre accueil…")
                            .frame(maxWidth: .infinity).padding(40)
                    }
                    disclaimer
                }
                .padding(16)
            }
            .background(KATheme.paper(scheme))
            .navigationTitle("")
            .toolbar {
                ToolbarItem(placement: .topBarLeading) {
                    GroupeKAMark(size: 16)
                }
            }
            .navigationDestination(for: KAItem.self) { ItemDetailView(item: $0) }
            .navigationDestination(for: String.self) { id in
                if let u = Ecosystem.universe(id) { UniverseHomeView(universe: u) }
            }
            .refreshable { await load() }
            .task { await load() }
        }
    }

    // MARK: sous-vues

    private var greeting: (title: String, sub: String) {
        let h = Calendar.current.component(.hour, from: Date())
        let weekend = Calendar.current.isDateInWeekend(Date())
        switch h {
        case 5..<12: return ("Bon matin ☀️", weekend ? "On planifie la fin de semaine ?" : "L'écosystème a travaillé toute la nuit.")
        case 12..<17: return ("Bon après-midi 👋", "Tout le Québec, dans votre poche.")
        case 17..<22: return ("Bonsoir 🌆", weekend ? "Resto ? Sortie ? KA a des idées." : "On soupe où ce soir ?")
        default: return ("Bonne nuit 🌙", "Les connecteurs veillent — revenez demain matin.")
        }
    }

    private var header: some View {
        VStack(alignment: .leading, spacing: 5) {
            Text(greeting.title).font(.system(.largeTitle, design: .rounded).weight(.bold))
            Text(greeting.sub).font(.subheadline).foregroundStyle(KATheme.ink2(scheme))
        }
    }

    private var pulseStrip: some View {
        ScrollView(.horizontal, showsIndicators: false) {
            HStack(spacing: 10) {
                ForEach(pulse, id: \.0.id) { (u, n) in
                    NavigationLink(value: u.id) {
                        VStack(alignment: .leading, spacing: 3) {
                            Text(n.formatted(.number.locale(Locale(identifier: "fr_CA"))))
                                .font(.system(.headline, design: .rounded).weight(.bold))
                                .foregroundStyle(u.accent)
                                .contentTransition(.numericText())
                            Text(u.unit).font(.caption2).foregroundStyle(.secondary)
                        }
                        .padding(.horizontal, 13).padding(.vertical, 9)
                        .kaCard(accent: u.accent)
                    }
                    .buttonStyle(.plain)
                }
                if pulse.isEmpty {
                    Text("Le pouls de l'écosystème…").font(.caption).foregroundStyle(.tertiary).padding(10)
                }
            }
        }
        .accessibilityLabel("Le pouls de l'écosystème en direct")
    }

    private func featuredSection(_ u: Universe, _ items: [KAItem]) -> some View {
        VStack(alignment: .leading, spacing: 10) {
            HStack {
                KAWordmark(universe: u, size: 17)
                Spacer()
                NavigationLink(value: u.id) {
                    Text("Tout voir").font(.caption.weight(.semibold)).foregroundStyle(u.accent)
                }
            }
            ScrollView(.horizontal, showsIndicators: false) {
                HStack(spacing: 12) {
                    ForEach(items.prefix(8)) { item in
                        NavigationLink(value: item) {
                            VStack(alignment: .leading, spacing: 0) {
                                KAImage(url: item.imageURL, accent: u.accent, symbol: u.symbol)
                                    .frame(width: 216, height: 118)
                                    .clipped()
                                VStack(alignment: .leading, spacing: 4) {
                                    Text(item.title).font(.subheadline.weight(.semibold))
                                        .lineLimit(2, reservesSpace: true)
                                        .multilineTextAlignment(.leading)
                                    HStack {
                                        if let p = item.priceLabel {
                                            Text(p).font(.system(.caption, design: .rounded).weight(.bold))
                                                .foregroundStyle(u.accent)
                                                .lineLimit(1)
                                        }
                                        Spacer()
                                        if let c = item.city {
                                            Text(c).font(.caption2).foregroundStyle(.tertiary).lineLimit(1)
                                        }
                                    }
                                }
                                .padding(10)
                            }
                            .frame(width: 216, alignment: .topLeading)
                            .kaCard(accent: u.accent)
                        }
                        .buttonStyle(KAPressStyle())
                    }
                }
                .scrollTargetLayout()
                .padding(.vertical, 4)
            }
            .scrollTargetBehavior(.viewAligned)
        }
    }

    /// Reprendre : derniers consultés + favoris récents + recherches sauvegardées avec alertes
    @ViewBuilder
    private var resumeStrip: some View {
        let hasContent = !recents.viewed.isEmpty || !favorites.allItems.isEmpty || !recents.savedSearches.isEmpty
        if hasContent {
            VStack(alignment: .leading, spacing: 10) {
                Text("Reprendre").font(.headline)
                ScrollView(.horizontal, showsIndicators: false) {
                    HStack(spacing: 10) {
                        ForEach(recents.savedSearches.prefix(3)) { s in
                            NavigationLink(value: s.universeID) {
                                HStack(spacing: 6) {
                                    Image(systemName: "bell.badge").font(.caption)
                                    Text(s.name).font(.caption.weight(.bold)).lineLimit(1)
                                    if s.newCount > 0 {
                                        Text("+\(s.newCount)")
                                            .font(.system(size: 10, design: .monospaced).weight(.bold))
                                            .padding(.horizontal, 6).padding(.vertical, 2)
                                            .background(.red, in: Capsule())
                                            .foregroundStyle(.white)
                                    }
                                }
                                .padding(.horizontal, 12).padding(.vertical, 9)
                                .kaCard()
                            }
                            .buttonStyle(KAPressStyle())
                        }
                        ForEach(recents.viewed.prefix(6)) { item in
                            NavigationLink(value: item) {
                                HStack(spacing: 8) {
                                    if let img = item.imageURL {
                                        KAImage(url: img, accent: Ecosystem.universe(item.universeID)?.accent ?? .gray)
                                            .frame(width: 34, height: 34)
                                            .clipShape(RoundedRectangle(cornerRadius: 7))
                                    } else {
                                        Image(systemName: "clock.arrow.circlepath").foregroundStyle(.secondary)
                                    }
                                    Text(item.title).font(.caption.weight(.semibold)).lineLimit(1)
                                }
                                .padding(.horizontal, 10).padding(.vertical, 7)
                                .kaCard(accent: Ecosystem.universe(item.universeID)?.accent)
                            }
                            .buttonStyle(KAPressStyle())
                        }
                    }
                }
            }
        }
    }

    /// Collections éditoriales : de vraies requêtes, du vrai contenu
    @ViewBuilder
    private var editorialSection: some View {
        ForEach(Editorial.collections) { c in
            if let items = editorialItems[c.id], !items.isEmpty,
               let u = Ecosystem.universe(c.universeID) {
                VStack(alignment: .leading, spacing: 10) {
                    HStack(spacing: 8) {
                        Image(systemName: c.symbol).foregroundStyle(u.accent)
                        VStack(alignment: .leading, spacing: 0) {
                            Text(c.title).font(.headline)
                            Text(c.subtitle).font(.caption).foregroundStyle(.secondary)
                        }
                        Spacer()
                        NavigationLink(value: u.id) {
                            Text("Tout voir").font(.caption.weight(.semibold)).foregroundStyle(u.accent)
                        }
                    }
                    ScrollView(.horizontal, showsIndicators: false) {
                        HStack(spacing: 12) {
                            ForEach(items.prefix(8)) { item in
                                NavigationLink(value: item) {
                                    VStack(alignment: .leading, spacing: 0) {
                                        KAImage(url: item.imageURL, accent: u.accent, symbol: u.symbol)
                                            .frame(width: 170, height: 96).clipped()
                                        VStack(alignment: .leading, spacing: 2) {
                                            Text(item.title).font(.caption.weight(.semibold))
                                                .lineLimit(2, reservesSpace: true)
                                            if let p = item.priceLabel {
                                                Text(p).font(.system(.caption2, design: .rounded).weight(.bold))
                                                    .foregroundStyle(u.accent)
                                            }
                                        }
                                        .padding(9)
                                    }
                                    .frame(width: 170, alignment: .topLeading)
                                    .kaCard(accent: u.accent)
                                }
                                .buttonStyle(KAPressStyle())
                            }
                        }
                        .scrollTargetLayout()
                        .padding(.vertical, 4)
                    }
                    .scrollTargetBehavior(.viewAligned)
                }
            }
        }
    }

    private var disclaimer: some View {
        Text(Ecosystem.disclaimer)
            .font(.caption2).foregroundStyle(.tertiary)
            .padding(.top, 8)
    }

    // MARK: données

    /// Univers mis en avant selon l'heure + les préférences d'onboarding.
    private var contextualUniverses: [Universe] {
        let h = Calendar.current.component(.hour, from: Date())
        let weekend = Calendar.current.isDateInWeekend(Date())
        var ids: [String]
        switch h {
        case 5..<11: ids = ["job-ka", "food-ka", "immo-ka"]
        case 11..<14: ids = ["resto-ka", "food-ka", "sorti-ka"]
        case 14..<17: ids = weekend ? ["sorti-ka", "resto-ka", "auto-ka"] : ["immo-ka", "auto-ka", "lou-ka"]
        case 17..<23: ids = ["resto-ka", "sorti-ka", "crea-ka"]
        default: ids = ["sorti-ka", "crea-ka", "lou-ka"]
        }
        let favs = favUniversesRaw.split(separator: ",").map(String.init)
        for f in favs.reversed() where !ids.contains(f) { ids.insert(f, at: 0) }
        return ids.prefix(4).compactMap(Ecosystem.universe).filter { $0.map != nil }
    }

    private func load() async {
        loading = true
        let universes = contextualUniverses
        var found: [String: [KAItem]] = [:]
        await withTaskGroup(of: (String, [KAItem]).self) { group in
            for u in universes {
                group.addTask { (u.id, (try? await UniverseService.fetch(u, limit: 8)) ?? []) }
            }
            for u in Ecosystem.all where u.statTotalKeys.first != nil {
                _ = u // pouls géré plus bas
            }
            for await (id, items) in group { found[id] = items }
        }
        featured = universes.compactMap { u in
            let items = found[u.id] ?? []
            return items.isEmpty ? nil : (u, items)
        }
        loading = false
        // pouls (compteurs live) — après le contenu pour ne pas retarder l'accueil
        var counts: [(Universe, Int)] = []
        await withTaskGroup(of: (String, Int?).self) { group in
            for u in Ecosystem.all {
                group.addTask { (u.id, await UniverseService.liveTotal(u)) }
            }
            for await (id, n) in group {
                if let n, let u = Ecosystem.universe(id) { counts.append((u, n)) }
            }
        }
        pulse = counts.sorted { $0.1 > $1.1 }
        // collections éditoriales (requêtes réelles)
        await withTaskGroup(of: (String, [KAItem]).self) { group in
            for c in Editorial.collections {
                if let u = Ecosystem.universe(c.universeID) {
                    group.addTask {
                        (c.id, (try? await UniverseService.fetch(u, query: c.query, limit: 8, params: c.params)) ?? [])
                    }
                }
            }
            for await (id, items) in group { editorialItems[id] = items }
        }
    }
}