//  Destinations.swift
//  GreenshotMac
//
//  Port of Greenshot's IDestination implementations for macOS.

import AppKit
import UniformTypeIdentifiers

@MainActor
enum Destinations {

    /// Sends a capture to a destination. `anchor` is used to position pickers and share sheets.
    @discardableResult
    static func export(_ capture: Capture,
                       to destination: DestinationID,
                       anchor: NSView? = nil) -> Bool {
        switch destination {
        case .picker:
            DestinationPickerWindowController.present(for: capture)
            return true
        case .editor:
            EditorWindowController.open(with: capture)
            return true
        case .clipboard:
            copyToClipboard(capture)
            Notifier.show(title: "Copied to clipboard", body: nil)
            return true
        case .file:
            return saveToFile(capture)
        case .fileWithDialog:
            return saveWithDialog(capture)
        case .printer:
            printCapture(capture)
            return true
        case .share:
            share(capture, anchor: anchor)
            return true
        case .email:
            sendAsEmail(capture, anchor: anchor)
            return true
        case .openWith:
            openWith(capture)
            return true
        }
    }

    // MARK: - Clipboard

    static func copyToClipboard(_ capture: Capture) {
        let pasteboard = NSPasteboard.general
        pasteboard.clearContents()
        let image = capture.nsImage
        pasteboard.writeObjects([image])
        if let data = ImageExporter.data(from: capture.image, format: .png, jpegQuality: 100) {
            pasteboard.setData(data, forType: .png)
        }
    }

    // MARK: - Files

    @discardableResult
    static func saveToFile(_ capture: Capture) -> Bool {
        let url = ImageExporter.suggestedURL(for: capture.details)
        do {
            try ImageExporter.write(capture.image, to: url, format: Configuration.shared.outputFileFormat)
            capture.details.filePath = url.path
            if Configuration.shared.copyPathToClipboard {
                NSPasteboard.general.clearContents()
                NSPasteboard.general.setString(url.path, forType: .string)
            }
            Notifier.show(title: "Screenshot saved", body: url.lastPathComponent, revealing: url)
            return true
        } catch {
            presentError(error)
            return false
        }
    }

    @discardableResult
    static func saveWithDialog(_ capture: Capture) -> Bool {
        let panel = NSSavePanel()
        let configuration = Configuration.shared
        panel.nameFieldStringValue = FilenamePattern.filename(pattern: configuration.outputFileFilenamePattern,
                                                              details: capture.details,
                                                              format: configuration.outputFileFormat)
        panel.directoryURL = URL(fileURLWithPath: configuration.outputFilePath, isDirectory: true)
        panel.allowedContentTypes = [.png, .jpeg, .tiff, .bmp, .gif]
        panel.canCreateDirectories = true
        panel.isExtensionHidden = false

        NSApp.activate(ignoringOtherApps: true)
        guard panel.runModal() == .OK, let url = panel.url else { return false }

        let format = ImageExporter.format(forPathExtension: url.pathExtension)
        do {
            try ImageExporter.write(capture.image, to: url, format: format)
            capture.details.filePath = url.path
            return true
        } catch {
            presentError(error)
            return false
        }
    }

    // MARK: - Print

    static func printCapture(_ capture: Capture) {
        let image = capture.nsImage
        let info = NSPrintInfo.shared
        info.horizontalPagination = .fit
        info.verticalPagination = .fit
        info.isHorizontallyCentered = true
        info.isVerticallyCentered = true
        info.orientation = image.size.width > image.size.height ? .landscape : .portrait

        let imageView = NSImageView(frame: CGRect(origin: .zero, size: image.size))
        imageView.image = image
        imageView.imageScaling = .scaleProportionallyUpOrDown

        let operation = NSPrintOperation(view: imageView, printInfo: info)
        operation.showsPrintPanel = true
        operation.showsProgressPanel = true
        NSApp.activate(ignoringOtherApps: true)
        operation.run()
    }

    // MARK: - Share

    static func share(_ capture: Capture, anchor: NSView?) {
        guard let url = writeTemporaryFile(capture) else { return }
        let picker = NSSharingServicePicker(items: [url])
        if let anchor {
            picker.show(relativeTo: anchor.bounds, of: anchor, preferredEdge: .minY)
        } else if let window = anchorWindow() {
            let view = window.contentView ?? NSView()
            picker.show(relativeTo: view.bounds, of: view, preferredEdge: .minY)
        }
    }

    // MARK: - Open with

    static func openWith(_ capture: Capture) {
        guard let url = writeTemporaryFile(capture) else { return }
        let panel = NSOpenPanel()
        panel.message = "Choose an application to open the screenshot with"
        panel.directoryURL = URL(fileURLWithPath: "/Applications")
        panel.allowedContentTypes = [.application]
        panel.allowsMultipleSelection = false
        panel.canChooseDirectories = false

        NSApp.activate(ignoringOtherApps: true)
        guard panel.runModal() == .OK, let application = panel.url else { return }
        NSWorkspace.shared.open([url],
                                withApplicationAt: application,
                                configuration: NSWorkspace.OpenConfiguration()) { _, error in
            if let error {
                DispatchQueue.main.async { presentError(error) }
            }
        }
    }

    // MARK: - Email

    static func sendAsEmail(_ capture: Capture, anchor: NSView?) {
        guard let url = writeTemporaryFile(capture) else { return }
        let subject = capture.details.title.isEmpty ? "Screenshot" : "Screenshot: \(capture.details.title)"

        if let service = NSSharingService(named: .composeEmail) {
            service.subject = subject
            service.perform(withItems: [url])
        } else {
            // No mail client is configured for the share service; fall back to the share sheet.
            share(capture, anchor: anchor)
        }
    }

    // MARK: - Helpers

    static func writeTemporaryFile(_ capture: Capture) -> URL? {
        let configuration = Configuration.shared
        let name = FilenamePattern.filename(pattern: configuration.outputFileFilenamePattern,
                                            details: capture.details,
                                            format: configuration.outputFileFormat)
        let directory = FileManager.default.temporaryDirectory
            .appendingPathComponent("GreenshotMac", isDirectory: true)
        let url = ImageExporter.uniqueURL(directory.appendingPathComponent(name))
        do {
            try ImageExporter.write(capture.image, to: url, format: configuration.outputFileFormat)
            return url
        } catch {
            presentError(error)
            return nil
        }
    }

    private static func anchorWindow() -> NSWindow? {
        NSApp.keyWindow ?? NSApp.windows.first { $0.isVisible }
    }

    static func presentError(_ error: Error) {
        let alert = NSAlert()
        alert.messageText = "GreenshotMac"
        alert.informativeText = error.localizedDescription
        alert.alertStyle = .warning
        alert.addButton(withTitle: "OK")
        NSApp.activate(ignoringOtherApps: true)
        alert.runModal()
    }
}