import SwiftUI
import OrgSocialKit

struct ProfileView: View {
    @Environment(\.openURL) private var openURL
    @State private var viewModel: ProfileViewModel
    @State private var showEditProfile = false
    @State private var isTogglingFollow = false
    @State private var followCoordinator = FollowCoordinator.shared
    @State private var searchQuery: String = ""

    private let feedURL: URL
    private var isFollowing: Bool { followCoordinator.isFollowing(feedURL) }
    private var isOwnProfile: Bool {
        guard let raw = UserDefaults.standard.string(forKey: "publicFeedURL"),
              let own = URL(string: raw) else { return false }
        return FollowCoordinator.normalize(own) == FollowCoordinator.normalize(feedURL)
    }

    init(feedURL: URL) {
        self.feedURL = feedURL
        _viewModel = State(initialValue: ProfileViewModel(feedURL: feedURL))
    }

    var body: some View {
        Group {
            if let profile = viewModel.profile {
                profileContent(profile)
            } else if let error = viewModel.errorMessage {
                ContentUnavailableView {
                    Label("Profile unavailable", systemImage: "person.slash")
                } description: {
                    Text(error)
                } actions: {
                    Button("Retry") { Task { await viewModel.load() } }
                        .buttonStyle(.bordered)
                }
            } else {
                ProgressView()
                    .frame(maxWidth: .infinity, maxHeight: .infinity)
            }
        }
        .navigationBarTitleDisplayMode(.inline)
        .toolbar { profileToolbar }
        .sheet(isPresented: $showEditProfile, onDismiss: {
            // Refresh profile so edits appear immediately.
            Task { await viewModel.reload() }
        }) {
            EditProfileView()
        }
        .task {
            // For the user's own profile bypass CDN cache so freshly-added
            // #+FOLLOW: entries and header edits show up immediately.
            if isOwnProfile {
                await viewModel.reload()
            } else {
                await viewModel.load()
            }
            await followCoordinator.refreshIfNeeded()
        }
        // Pull-to-refresh: always bypass the CDN so the user can force
        // a fresh read (e.g. after composing from another device).
        .refreshable {
            await viewModel.reload()
            await followCoordinator.forceRefresh()
        }
        // Search inside the profile's posts. Case-insensitive substring
        // match on body + tags. Keeps profile browsing usable for feeds
        // that have accumulated hundreds of posts.
        .searchable(text: $searchQuery, placement: .navigationBarDrawer(displayMode: .automatic),
                    prompt: "Search posts")
        .onChange(of: followCoordinator.feedVersion) { _, _ in
            // Own feed changed elsewhere (compose, edit, delete, follow toggle, profile edit).
            // SwiftUI's TabView preserves state so .task doesn't fire again; this hook does.
            if isOwnProfile {
                Task { await viewModel.reload() }
            }
        }
    }

    @ViewBuilder
    private func profileContent(_ profile: OrgSocialProfile) -> some View {
        List {
            // MARK: Header section
            Section {
                VStack(spacing: 16) {
                    AvatarView(url: profile.avatar, nick: profile.nick, size: 80)

                    VStack(spacing: 4) {
                        if let nick = profile.nick {
                            Text("@\(nick)")
                                .font(.title2.weight(.bold))
                        }
                        if let title = profile.title {
                            Text(title)
                                .font(.subheadline)
                                .foregroundStyle(.secondary)
                                .multilineTextAlignment(.center)
                        }
                    }

                    if let description = profile.description {
                        Text(description)
                            .font(.body)
                            .multilineTextAlignment(.center)
                            .foregroundStyle(.primary)
                    }

                    // Two-row HStack-of-HStacks: keeps the three small
                    // buttons readable on iPhone SE-sized screens where
                    // a single row would overflow when "View blog" is
                    // present (vfile-hosted feeds only).
                    VStack(spacing: 8) {
                        HStack(spacing: 8) {
                            Button {
                                openURL(feedURL)
                            } label: {
                                Label("View social.org", systemImage: "safari")
                                    .font(.caption.weight(.medium))
                            }
                            .buttonStyle(.bordered)
                            .controlSize(.small)

                            if let rssURL = rssFeedURL {
                                ShareLink(item: rssURL) {
                                    Label("Share RSS", systemImage: "dot.radiowaves.up.forward")
                                        .font(.caption.weight(.medium))
                                }
                                .buttonStyle(.bordered)
                                .controlSize(.small)
                            }
                        }
                        if let blogURL = vfileBlogURL {
                            Button {
                                openURL(blogURL)
                            } label: {
                                Label("View blog", systemImage: "doc.richtext")
                                    .font(.caption.weight(.medium))
                            }
                            .buttonStyle(.bordered)
                            .controlSize(.small)
                        }
                    }
                }
                .frame(maxWidth: .infinity)
                .padding(.vertical, 8)
            }

            // MARK: Meta section
            let hasMeta = profile.location != nil || profile.birthday != nil || !profile.languages.isEmpty || !profile.links.isEmpty || !profile.contacts.isEmpty
            if hasMeta {
                Section("Info") {
                    if let location = profile.location {
                        metaRow(icon: "mappin", text: location)
                    }
                    if let birthday = profile.birthday {
                        metaRow(icon: "gift", text: birthday)
                    }
                    if !profile.languages.isEmpty {
                        metaRow(icon: "globe", text: profile.languages.joined(separator: ", "))
                    }
                    ForEach(profile.links, id: \.absoluteString) { link in
                        Link(destination: link) {
                            // Show the full URL (scheme + host + path) so the
                            // user can tell apart entries that share a host
                            // (e.g. https://andros.dev vs gemini://andros.dev)
                            // and see paths instead of just the host.
                            metaRow(icon: "link", text: link.absoluteString, tinted: true, wraps: true)
                        }
                    }
                    ForEach(profile.contacts, id: \.self) { contact in
                        metaRow(icon: "envelope", text: contact, wraps: true)
                    }
                }
            }

            // MARK: Follows section
            if !profile.follows.isEmpty {
                Section("Following (\(profile.follows.count))") {
                    ForEach(profile.follows, id: \.url) { follow in
                        let details = viewModel.enrichedFollows[follow.url]
                        let displayNick = follow.name ?? details?.nick
                        NavigationLink(value: follow.url) {
                            HStack(spacing: 10) {
                                AvatarView(url: details?.avatar, nick: displayNick, size: 32)
                                VStack(alignment: .leading, spacing: 2) {
                                    if let displayNick {
                                        Text(displayNick)
                                            .font(.subheadline.weight(.semibold))
                                    }
                                    Text(follow.url.host ?? follow.url.absoluteString)
                                        .font(.caption)
                                        .foregroundStyle(.secondary)
                                        .lineLimit(1)
                                }
                            }
                        }
                    }
                }
            }

            // MARK: Groups section
            if !profile.groups.isEmpty {
                Section("Groups (\(profile.groups.count))") {
                    ForEach(profile.groups, id: \.name) { group in
                        HStack(spacing: 10) {
                            Image(systemName: "person.3.fill")
                                .foregroundStyle(.secondary)
                                .frame(width: 20)
                            VStack(alignment: .leading, spacing: 2) {
                                Text(group.name).font(.subheadline.weight(.semibold))
                                Text(group.relayURL.host ?? group.relayURL.absoluteString)
                                    .font(.caption).foregroundStyle(.secondary)
                            }
                        }
                    }
                }
            }

            // MARK: Pinned post
            if let pinnedTimestamp = profile.pinned,
               let pinned = profile.posts.first(where: { $0.timestamp == pinnedTimestamp }) {
                Section {
                    PostRowView(post: enriched(pinned, profile: profile),
                                onDelete: { viewModel.removePost(timestamp: pinned.timestamp) },
                                onEdit: { result in viewModel.applyEdit(timestamp: pinned.timestamp, result: result) })
                        .listRowSeparator(.hidden)
                        .listRowInsets(EdgeInsets(top: 12, leading: 16, bottom: 12, trailing: 16))
                        .listRowBackground(Color.accentColor.opacity(0.04))
                } header: {
                    Label("Pinned", systemImage: "pin.fill").font(.caption.weight(.semibold))
                }
            }

            // MARK: Posts section
            // Pure reactions / boosts / votes are protocol artefacts and are
            // filtered out the same way as on the timeline — the profile
            // shows the user's authored content, not a log of their reactions.
            let displayPosts = profile.posts
                .filter { !$0.isPureInteraction }
                .filter { matchesSearch($0, query: searchQuery) }
            if !displayPosts.isEmpty {
                Section("Posts (\(displayPosts.count))") {
                    ForEach(displayPosts.reversed(), id: \.timestamp) { post in
                        PostRowView(post: enriched(post, profile: profile),
                                    onDelete: { viewModel.removePost(timestamp: post.timestamp) },
                                    onEdit: { result in viewModel.applyEdit(timestamp: post.timestamp, result: result) })
                            .listRowSeparator(.visible)
                            .listRowSeparatorTint(Color.secondary.opacity(0.2))
                            .listRowInsets(EdgeInsets(top: 12, leading: 16, bottom: 12, trailing: 16))
                            .listRowBackground(Color.clear)
                    }
                }
            }
        }
        .listStyle(.insetGrouped)
        .navigationDestination(for: URL.self) { ProfileView(feedURL: $0) }
        .navigationDestination(for: ThreadRoute.self) {
            ThreadView(postURL: $0.postURL, relayURL: $0.relayURL)
        }
    }

    /// Builds the preview service's blog URL when the feed looks like a
    /// vfile-hosted feed (path shape `/<nick>/social.org`). For feeds
    /// served from raw Git or arbitrary HTTP locations the path doesn't
    /// match, so the button is hidden. The base comes from the configured
    /// preview service URL (Settings -> Sharing) so a user pointing at a
    /// self-hosted preview instance gets the same affordance.
    private var vfileBlogURL: URL? {
        let segments = feedURL.path.split(separator: "/").map(String.init)
        guard segments.count >= 2,
              segments.last?.lowercased() == "social.org" else {
            return nil
        }
        let nick = segments[segments.count - 2]
        guard !nick.isEmpty else { return nil }
        let raw = (UserDefaults.standard.string(forKey: "previewServiceURL") ?? "https://preview.org-social.org/")
            .trimmingCharacters(in: .whitespaces)
        let base = raw.hasSuffix("/") ? String(raw.dropLast()) : raw
        return URL(string: "\(base)/blog/\(nick)")
    }

    /// Builds the relay's per-feed RSS URL from the configured relay base.
    /// Falls back to nil when no relay is configured so the Share button
    /// stays hidden (the lib also exposes `/rss.xml` only on the relay).
    private var rssFeedURL: URL? {
        let raw = UserDefaults.standard.string(forKey: "relayURL") ?? ""
        guard let relay = URL(string: raw) else { return nil }
        let base = relay.absoluteString.trimmingCharacters(in: CharacterSet(charactersIn: "/"))
        var allowed = CharacterSet.urlQueryAllowed
        allowed.remove(charactersIn: "+")
        let encoded = feedURL.absoluteString.addingPercentEncoding(withAllowedCharacters: allowed)
            ?? feedURL.absoluteString
        return URL(string: "\(base)/rss.xml?feed=\(encoded)")
    }

    private func matchesSearch(_ post: OrgSocialPost, query: String) -> Bool {
        let trimmed = query.trimmingCharacters(in: .whitespacesAndNewlines)
        guard !trimmed.isEmpty else { return true }
        let needle = trimmed.lowercased()
        if post.text.lowercased().contains(needle) { return true }
        if post.tags.contains(where: { $0.lowercased().contains(needle) }) { return true }
        return false
    }

    private func enriched(_ post: OrgSocialPost, profile: OrgSocialProfile) -> OrgSocialPost {
        var p = post
        p.authorNick = profile.nick
        p.authorURL = profile.feedURL
        p.authorAvatar = profile.avatar
        p.feedURL = profile.feedURL
        return p
    }

    @ToolbarContentBuilder
    private var profileToolbar: some ToolbarContent {
        ToolbarItemGroup(placement: .navigationBarTrailing) {
            if isOwnProfile {
                Button { showEditProfile = true } label: {
                    Image(systemName: "pencil")
                }
            } else {
                if isTogglingFollow {
                    ProgressView()
                } else {
                    Button {
                        Task { await toggleFollow() }
                    } label: {
                        Text(isFollowing ? "Unfollow" : "Follow")
                            .fontWeight(isFollowing ? .regular : .semibold)
                    }
                }
            }
        }
    }

    private func toggleFollow() async {
        isTogglingFollow = true
        defer { isTogglingFollow = false }
        let nick = viewModel.profile?.nick
        await followCoordinator.toggle(url: feedURL, nick: nick)
    }

    private func metaRow(icon: String, text: String, tinted: Bool = false, wraps: Bool = false) -> some View {
        HStack(alignment: wraps ? .top : .center, spacing: 10) {
            Image(systemName: icon)
                .foregroundStyle(.secondary)
                .frame(width: 20)
            Text(text)
                .foregroundStyle(tinted ? Color.accentColor : Color.primary)
                .lineLimit(wraps ? nil : 1)
                .fixedSize(horizontal: false, vertical: wraps)
                .multilineTextAlignment(.leading)
                .frame(maxWidth: .infinity, alignment: .leading)
        }
    }
}