import SwiftUI

// ──────────────────────────────────────────────────────────────────────
// LicensesView.swift
// Displays all open-source licenses for dependencies used in the app
// and the Companion API server.
// ──────────────────────────────────────────────────────────────────────

struct LicenseItem: Identifiable {
    let id = UUID()
    let name: String
    let description: String
    let license: String
    let url: String
    let category: String  // "App" or "Companion API"
}

struct LicensesView: View {
    private let accentPink = Color(red: 1.0, green: 0.176, blue: 0.333)
    
    private let licenses: [LicenseItem] = [
        // ── iOS App ──
        LicenseItem(
            name: "ZIPFoundation",
            description: "Effortless ZIP handling in Swift",
            license: "MIT License",
            url: "https://github.com/weichsel/ZIPFoundation",
            category: "App"
        ),
        
        // ── Companion API (Python) ──
        LicenseItem(
            name: "FastAPI",
            description: "Modern, fast web framework for building APIs with Python",
            license: "MIT License",
            url: "https://github.com/tiangolo/fastapi",
            category: "Companion API"
        ),
        LicenseItem(
            name: "Uvicorn",
            description: "Lightning-fast ASGI server for Python",
            license: "BSD License",
            url: "https://github.com/encode/uvicorn",
            category: "Companion API"
        ),
        LicenseItem(
            name: "Mutagen",
            description: "Python module to handle audio metadata",
            license: "GPL-2.0 License",
            url: "https://github.com/quodlibet/mutagen",
            category: "Companion API"
        ),
        LicenseItem(
            name: "httpx",
            description: "Fully featured HTTP client for Python 3",
            license: "BSD License",
            url: "https://github.com/encode/httpx",
            category: "Companion API"
        ),
        LicenseItem(
            name: "NumPy",
            description: "Fundamental package for scientific computing with Python",
            license: "BSD License",
            url: "https://github.com/numpy/numpy",
            category: "Companion API"
        ),
        LicenseItem(
            name: "Pydantic",
            description: "Data validation using Python type annotations",
            license: "MIT License",
            url: "https://github.com/pydantic/pydantic",
            category: "Companion API"
        ),
        LicenseItem(
            name: "librosa",
            description: "Python library for audio and music analysis",
            license: "ISC License",
            url: "https://github.com/librosa/librosa",
            category: "Companion API"
        ),
    ]
    
    private var appLicenses: [LicenseItem] {
        licenses.filter { $0.category == "App" }
    }
    
    private var companionLicenses: [LicenseItem] {
        licenses.filter { $0.category == "Companion API" }
    }
    
    var body: some View {
        List {
            Section {
                VStack(alignment: .leading, spacing: 6) {
                    Text("NavidromePlayer uses the following open-source libraries. We're grateful to the developers and communities behind these projects.")
                        .font(.system(size: 13))
                        .foregroundStyle(.secondary)
                }
                .padding(.vertical, 4)
            }
            
            Section("App") {
                ForEach(appLicenses) { item in
                    licenseRow(item)
                }
            }
            
            Section("Companion API") {
                ForEach(companionLicenses) { item in
                    licenseRow(item)
                }
            }
            
            Section {
                VStack(alignment: .leading, spacing: 6) {
                    Text("Visualizer")
                        .font(.system(size: 15, weight: .semibold))
                    Text("The audio visualizer is inspired by Mitsuha, originally created by c0ldra1n for jailbroken iOS. This is an independent reimplementation using Apple frameworks.")
                        .font(.system(size: 13))
                        .foregroundStyle(.secondary)
                }
                .padding(.vertical, 4)
            } header: {
                Text("Acknowledgments")
            }
            
            Section {} footer: { Spacer().frame(height: 80) }
        }
        .navigationTitle("Licenses")
    }
    
    private func licenseRow(_ item: LicenseItem) -> some View {
        VStack(alignment: .leading, spacing: 4) {
            HStack {
                Text(item.name)
                    .font(.system(size: 15, weight: .semibold))
                Spacer()
                Text(item.license)
                    .font(.system(size: 11, weight: .medium))
                    .foregroundStyle(accentPink)
                    .padding(.horizontal, 8)
                    .padding(.vertical, 3)
                    .background(
                        Capsule()
                            .fill(accentPink.opacity(0.12))
                    )
            }
            
            Text(item.description)
                .font(.system(size: 13))
                .foregroundStyle(.secondary)
                .lineLimit(2)
            
            if let url = URL(string: item.url) {
                Link(destination: url) {
                    Text(item.url.replacingOccurrences(of: "https://", with: ""))
                        .font(.system(size: 11))
                        .foregroundStyle(.blue.opacity(0.8))
                        .lineLimit(1)
                        .truncationMode(.middle)
                }
            }
        }
        .padding(.vertical, 4)
    }
}

#if DEBUG
#Preview {
    NavigationStack {
        LicensesView()
    }
}
#endif