import SwiftUI

// ──────────────────────────────────────────────────────────────────────
// LyricsSearchSheet.swift
// Search LRCLIB for lyrics, preview results, and import into the app.
// Presented as a sheet from Now Playing or Track Editor.
// ──────────────────────────────────────────────────────────────────────

struct LyricsSearchSheet: View {
    @Environment(\.dismiss) var dismiss
    @ObservedObject var audioPlayer = AudioPlayer.shared
    
    @State private var query: String
    @State private var results: [LRCLIBResult] = []
    @State private var isSearching = false
    @State private var selectedResult: LRCLIBResult?
    @State private var showPreview = false
    @State private var errorMessage: String?
    
    private let accentPink = Color(red: 1.0, green: 0.176, blue: 0.333)
    
    /// Initialize with a pre-filled query (typically "artist title")
    init(initialQuery: String = "") {
        _query = State(initialValue: initialQuery)
    }
    
    var body: some View {
        NavigationStack {
            VStack(spacing: 0) {
                // Search bar
                HStack(spacing: 12) {
                    Image(systemName: "magnifyingglass")
                        .foregroundStyle(.gray)
                    TextField("Search lyrics...", text: $query)
                        .textFieldStyle(.plain)
                        .autocorrectionDisabled()
                        .onSubmit { search() }
                    
                    if !query.isEmpty {
                        Button {
                            query = ""
                            results = []
                        } label: {
                            Image(systemName: "xmark.circle.fill")
                                .foregroundStyle(.gray)
                        }
                    }
                }
                .padding(12)
                .background(
                    RoundedRectangle(cornerRadius: 12, style: .continuous)
                        .fill(Color(.systemGray6))
                )
                .padding(.horizontal, 16)
                .padding(.top, 8)
                
                if isSearching {
                    Spacer()
                    ProgressView("Searching...")
                        .foregroundStyle(.secondary)
                    Spacer()
                } else if let error = errorMessage {
                    Spacer()
                    VStack(spacing: 8) {
                        Image(systemName: "exclamationmark.triangle")
                            .font(.system(size: 28))
                            .foregroundStyle(.orange)
                        Text(error)
                            .font(.system(size: 14))
                            .foregroundStyle(.secondary)
                            .multilineTextAlignment(.center)
                    }
                    .padding(.horizontal, 40)
                    Spacer()
                } else if results.isEmpty && !query.isEmpty {
                    Spacer()
                    Text("No results found")
                        .foregroundStyle(.secondary)
                    Spacer()
                } else {
                    List(results) { result in
                        Button {
                            selectedResult = result
                            showPreview = true
                        } label: {
                            resultRow(result)
                        }
                        .listRowBackground(Color.clear)
                    }
                    .listStyle(.plain)
                }
            }
            .navigationTitle("Search Lyrics")
            .navigationBarTitleDisplayMode(.inline)
            .toolbar {
                ToolbarItem(placement: .cancellationAction) {
                    Button("Cancel") { dismiss() }
                }
            }
            .sheet(isPresented: $showPreview) {
                if let result = selectedResult {
                    LyricsPreviewSheet(result: result) {
                        // On import
                        importResult(result)
                        dismiss()
                    }
                }
            }
            .onAppear {
                if !query.isEmpty { search() }
            }
        }
    }
    
    // MARK: - Result Row
    
    private func resultRow(_ result: LRCLIBResult) -> some View {
        VStack(alignment: .leading, spacing: 4) {
            HStack {
                Text(result.trackName)
                    .font(.system(size: 15, weight: .semibold))
                    .foregroundStyle(.white)
                    .lineLimit(1)
                Spacer()
                if result.hasSynced {
                    Text("Synced")
                        .font(.system(size: 10, weight: .semibold))
                        .foregroundStyle(.green)
                        .padding(.horizontal, 8)
                        .padding(.vertical, 3)
                        .background(Capsule().fill(.green.opacity(0.15)))
                } else if result.hasPlain {
                    Text("Plain")
                        .font(.system(size: 10, weight: .semibold))
                        .foregroundStyle(.gray)
                        .padding(.horizontal, 8)
                        .padding(.vertical, 3)
                        .background(Capsule().fill(.gray.opacity(0.15)))
                }
            }
            
            HStack(spacing: 6) {
                Text(result.artistName)
                    .font(.system(size: 13))
                    .foregroundStyle(.secondary)
                    .lineLimit(1)
                
                if let album = result.albumName, !album.isEmpty {
                    Text("·")
                        .foregroundStyle(.secondary.opacity(0.5))
                    Text(album)
                        .font(.system(size: 13))
                        .foregroundStyle(.secondary.opacity(0.7))
                        .lineLimit(1)
                }
                
                Text("·")
                    .foregroundStyle(.secondary.opacity(0.5))
                Text(formatDuration(result.duration))
                    .font(.system(size: 13).monospacedDigit())
                    .foregroundStyle(.secondary)
            }
            
            // Duration mismatch warning
            if audioPlayer.duration > 0 {
                let diff = abs(result.duration - audioPlayer.duration)
                if diff > 10 {
                    HStack(spacing: 4) {
                        Image(systemName: "exclamationmark.triangle.fill")
                            .font(.system(size: 10))
                        Text("Duration differs by \(formatDuration(diff))")
                            .font(.system(size: 11))
                    }
                    .foregroundStyle(.orange.opacity(0.8))
                    .padding(.top, 2)
                }
            }
        }
        .padding(.vertical, 4)
    }
    
    // MARK: - Actions
    
    private func search() {
        guard !query.trimmingCharacters(in: .whitespaces).isEmpty else { return }
        isSearching = true
        errorMessage = nil
        
        Task {
            do {
                let fetched = try await LyricsService.shared.search(query: query)
                await MainActor.run {
                    results = fetched
                    isSearching = false
                }
            } catch {
                await MainActor.run {
                    isSearching = false
                    errorMessage = "Search failed: \(error.localizedDescription)"
                }
            }
        }
    }
    
    private func importResult(_ result: LRCLIBResult) {
        if let synced = result.syncedLyrics {
            LyricsManager.shared.importLRC(synced, source: "lrclib")
        } else if let plain = result.plainLyrics {
            LyricsManager.shared.importPlain(plain, source: "lrclib")
        }
    }
    
    private func formatDuration(_ seconds: Double) -> String {
        let total = Int(max(seconds, 0))
        return String(format: "%d:%02d", total / 60, total % 60)
    }
}

// MARK: - Preview Sheet

struct LyricsPreviewSheet: View {
    let result: LRCLIBResult
    let onImport: () -> Void
    @Environment(\.dismiss) var dismiss
    
    private let accentPink = Color(red: 1.0, green: 0.176, blue: 0.333)
    
    var body: some View {
        NavigationStack {
            ScrollView {
                VStack(alignment: .leading, spacing: 8) {
                    // Header
                    VStack(alignment: .leading, spacing: 4) {
                        Text(result.trackName)
                            .font(.system(size: 20, weight: .bold))
                        Text(result.artistName)
                            .font(.system(size: 16))
                            .foregroundStyle(.secondary)
                        if let album = result.albumName {
                            Text(album)
                                .font(.system(size: 14))
                                .foregroundStyle(.secondary.opacity(0.7))
                        }
                    }
                    .padding(.bottom, 12)
                    
                    Divider()
                    
                    // Lyrics text
                    let text = result.syncedLyrics ?? result.plainLyrics ?? "No lyrics"
                    Text(text)
                        .font(.system(size: 15))
                        .foregroundStyle(.white.opacity(0.8))
                        .lineSpacing(6)
                        .padding(.top, 8)
                }
                .padding(20)
            }
            .navigationTitle("Preview")
            .navigationBarTitleDisplayMode(.inline)
            .toolbar {
                ToolbarItem(placement: .cancellationAction) {
                    Button("Cancel") { dismiss() }
                }
                ToolbarItem(placement: .confirmationAction) {
                    Button("Use These Lyrics") {
                        onImport()
                        dismiss()
                    }
                    .foregroundStyle(accentPink)
                    .fontWeight(.semibold)
                }
            }
        }
    }
}