import MusicAssistantCore
import SwiftUI
import WebKit

struct SunoHandoffSheet: View {
    let payload: SunoHandoffPayload
    let onComplete: (SunoFieldFillReport) -> Void

    @Environment(\.dismiss) private var dismiss
    @State private var report: SunoFieldFillReport?

    var body: some View {
        VStack(spacing: 0) {
            HStack {
                Text("Send to Suno")
                    .font(.headline)
                Spacer()
                Button("Close") {
                    dismiss()
                }
            }
            .padding(12)

            Divider()

            SunoCreateWebView(payload: payload) { report in
                self.report = report
                onComplete(report)
            }

            if let report {
                HStack {
                    Label(statusText(for: report), systemImage: statusIcon(for: report))
                        .font(.caption)
                        .foregroundStyle(statusColor(for: report))
                    Spacer()
                }
                .padding(12)
            }
        }
        .frame(minWidth: 900, minHeight: 650)
    }

    private func statusText(for report: SunoFieldFillReport) -> String {
        report.results.values.contains { if case .copyRequired = $0 { return true }; return false }
            ? "Some fields need manual copying."
            : "Suno fields are ready."
    }

    private func statusIcon(for report: SunoFieldFillReport) -> String {
        report.results.values.contains { if case .copyRequired = $0 { return true }; return false }
            ? "exclamationmark.triangle.fill"
            : "checkmark.circle.fill"
    }

    private func statusColor(for report: SunoFieldFillReport) -> Color {
        report.results.values.contains { if case .copyRequired = $0 { return true }; return false }
            ? .orange
            : .green
    }
}

private struct SunoCreateWebView: NSViewRepresentable {
    let payload: SunoHandoffPayload
    let onReport: (SunoFieldFillReport) -> Void

    func makeCoordinator() -> Coordinator {
        Coordinator(payload: payload, onReport: onReport)
    }

    func makeNSView(context: Context) -> WKWebView {
        let configuration = WKWebViewConfiguration()
        configuration.websiteDataStore = .default()
        let webView = WKWebView(frame: .zero, configuration: configuration)
        webView.navigationDelegate = context.coordinator
        webView.load(URLRequest(url: SunoHandoffDestination.createPageURL))
        return webView
    }

    func updateNSView(_ webView: WKWebView, context: Context) {}

    final class Coordinator: NSObject, WKNavigationDelegate {
        let payload: SunoHandoffPayload
        let onReport: (SunoFieldFillReport) -> Void

        init(payload: SunoHandoffPayload, onReport: @escaping (SunoFieldFillReport) -> Void) {
            self.payload = payload
            self.onReport = onReport
        }

        func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
            webView.evaluateJavaScript(fillScript()) { value, _ in
                guard let json = value as? String,
                      let data = json.data(using: .utf8),
                      let values = try? JSONSerialization.jsonObject(with: data) as? [String: Bool] else {
                    self.onReport(.copyRequired(for: SunoHandoffField.allCases, reason: "Suno fields could not be inspected."))
                    return
                }

                let results: [SunoHandoffField: SunoFieldFillResult] = Dictionary(
                    uniqueKeysWithValues: SunoHandoffField.allCases.map { field in
                        (field, values[field.rawValue] == true
                            ? SunoFieldFillResult.filled
                            : SunoFieldFillResult.copyRequired("The \(field.displayName) field was not found."))
                    }
                )
                self.onReport(SunoFieldFillReport(results: results))
            }
        }

        private func fillScript() -> String {
            let payloadData = try! JSONEncoder().encode(payload)
            let payloadJSON = String(data: payloadData, encoding: .utf8)!
                .replacingOccurrences(of: "\\", with: "\\\\")
                .replacingOccurrences(of: "'", with: "\\'")

            return """
            (() => {
              const payload = JSON.parse('\(payloadJSON)');
              const fields = { title: false, lyrics: false, stylePrompt: false };
              const custom = [...document.querySelectorAll('button,[role="button"]')].find(e => /custom/i.test(e.innerText));
              if (custom) custom.click();
              const candidates = [...document.querySelectorAll('input,textarea,[contenteditable="true"]')];
              const label = e => [e.getAttribute('aria-label'), e.getAttribute('placeholder'), e.name, e.id].filter(Boolean).join(' ');
              const set = (terms, value, key) => {
                const element = candidates.find(e => terms.some(term => label(e).toLowerCase().includes(term)));
                if (!element || !value) return;
                if (element.isContentEditable) element.textContent = value; else element.value = value;
                element.dispatchEvent(new Event('input', { bubbles: true }));
                element.dispatchEvent(new Event('change', { bubbles: true }));
                fields[key] = true;
              };
              set(['title'], payload.title, 'title');
              set(['lyric'], payload.lyrics, 'lyrics');
              set(['style','prompt'], payload.stylePrompt, 'stylePrompt');
              return JSON.stringify(fields);
            })();
            """
        }
    }
}