import SwiftUI

struct NoteListView: View {
    @EnvironmentObject var client: WebDAVClient
    @State private var searchText = ""
    @State private var themeManager = ThemeManager.shared
    let onSettings: () -> Void

    private var filteredNotes: [DenoteNote] {
        guard !searchText.isEmpty else { return client.notes }
        let q = searchText.lowercased()
        return client.notes.filter {
            $0.title.lowercased().contains(q) ||
            $0.keywords.joined(separator: " ").lowercased().contains(q) ||
            ($0.content?.lowercased().contains(q) == true)
        }
    }

    var body: some View {
        NavigationStack {
            VStack(spacing: 0) {
                searchBar
                if client.isLoading {
                    Spacer()
                    ProgressView("Loading notes...")
                    Spacer()
                } else if let error = client.errorMessage {
                    errorView(message: error)
                } else {
                    notesList
                }
            }
            .background(themeManager.current.background)
            .toolbarBackground(themeManager.current.secondaryBackground, for: .navigationBar)
            .toolbar {
                ToolbarItem(placement: .navigationBarLeading) {
                    Button { onSettings() } label: {
                        Image(systemName: "gearshape")
                    }
                }
                if client.isPrefetching {
                    ToolbarItem(placement: .navigationBarTrailing) {
                        HStack(spacing: 6) {
                            ProgressView().scaleEffect(0.75)
                            Text("Indexing").font(.caption).foregroundStyle(.secondary)
                        }
                    }
                }
            }
        }
        .task { await client.loadNotes() }
    }

    private var searchBar: some View {
        HStack(spacing: 8) {
            Image(systemName: "magnifyingglass")
                .foregroundStyle(.secondary)
            TextField("Search notes", text: $searchText)
                .autocorrectionDisabled()
            if !searchText.isEmpty {
                Button { searchText = "" } label: {
                    Image(systemName: "xmark.circle.fill")
                        .foregroundStyle(.tertiary)
                }
            }
        }
        .padding(.horizontal, 12)
        .padding(.vertical, 9)
        .background(themeManager.current.secondaryBackground)
        .clipShape(RoundedRectangle(cornerRadius: 10))
        .padding(.horizontal, 16)
        .padding(.vertical, 8)
        .background(themeManager.current.background)
    }

    private var notesList: some View {
        List(filteredNotes) { note in
            NavigationLink(destination: NoteDetailView(note: note)) {
                NoteRowView(note: note)
            }
        }
        .listStyle(.plain)
        .scrollContentBackground(.hidden)
        .background(themeManager.current.background)
        .refreshable { await client.loadNotes() }
        .overlay {
            if !searchText.isEmpty && filteredNotes.isEmpty {
                ContentUnavailableView.search(text: searchText)
            }
        }
    }

    private func errorView(message: String) -> some View {
        VStack(spacing: 16) {
            Image(systemName: "wifi.exclamationmark")
                .font(.system(size: 48))
                .foregroundStyle(.secondary)
            Text(message)
                .multilineTextAlignment(.center)
                .foregroundStyle(.secondary)
            Button("Retry") { Task { await client.loadNotes() } }
                .buttonStyle(.bordered)
        }
        .padding()
        .frame(maxWidth: .infinity, maxHeight: .infinity)
    }
}

struct NoteRowView: View {
    let note: DenoteNote

    var body: some View {
        VStack(alignment: .leading, spacing: 6) {
            Text(note.displayTitle)
                .font(.headline)
                .lineLimit(2)
            if !note.keywords.isEmpty {
                HStack(spacing: 4) {
                    ForEach(note.keywords, id: \.self) { keyword in
                        Text(keyword)
                            .font(.caption2)
                            .padding(.horizontal, 6)
                            .padding(.vertical, 2)
                            .background(Color.accentColor.opacity(0.15))
                            .foregroundStyle(Color.accentColor)
                            .clipShape(Capsule())
                    }
                }
            }
            if !note.formattedDate.isEmpty {
                Text(note.formattedDate)
                    .font(.caption)
                    .foregroundStyle(.secondary)
            }
        }
        .padding(.vertical, 2)
    }
}