Add lead workflows, PDF signing, AR projects and photo gallery integration

GasTankAR/Services/Signing/DefaultPDFSigningService.swift

@@ -0,0 +1,76 @@
+import Foundation
+import PDFKit
+import PencilKit
+import UIKit
+
+@MainActor
+struct DefaultPDFSigningService: PDFSigningService {
+    var outputDirectory: URL = URL.applicationSupportDirectory
+        .appending(path: "SignedLeadDocuments", directoryHint: .isDirectory)
+
+    func sign(source: URL, drawing: PKDrawing, placement: PDFSignaturePlacement) async throws -> URL {
+        try Task.checkCancellation()
+        guard !drawing.strokes.isEmpty else { throw PDFSigningError.emptySignature }
+        guard let document = PDFDocument(url: source), !document.isLocked else {
+            throw PDFSigningError.invalidDocument
+        }
+        guard placement.pageIndex >= 0,
+              let page = document.page(at: placement.pageIndex),
+              placement.bounds.width > 0, placement.bounds.height > 0,
+              page.bounds(for: .mediaBox).contains(placement.bounds) else {
+            throw PDFSigningError.invalidPlacement
+        }
+
+        // Fit the handwriting into the configured field without changing its aspect ratio.
+        // PencilKit uses a top-left origin; PDF page coordinates use a bottom-left origin.
+        let sourceBounds = drawing.bounds.insetBy(dx: -2, dy: -2)
+        let target = placement.bounds.insetBy(dx: 4, dy: 4)
+        guard target.width > 0, target.height > 0,
+              sourceBounds.width.isFinite, sourceBounds.height.isFinite else {
+            throw PDFSigningError.invalidPlacement
+        }
+        let scale = min(target.width / sourceBounds.width, target.height / sourceBounds.height)
+        let origin = CGPoint(x: target.midX - sourceBounds.width * scale / 2,
+                             y: target.midY - sourceBounds.height * scale / 2)
+        let annotation = PDFAnnotation(bounds: placement.bounds, forType: .ink, withProperties: nil)
+        annotation.color = .black
+        let border = PDFBorder()
+        border.lineWidth = max(0.7, 2 * scale)
+        annotation.border = border
+        annotation.shouldPrint = true
+
+        for stroke in drawing.strokes {
+            let path = UIBezierPath()
+            var isFirst = true
+            for point in stroke.path.interpolatedPoints(by: .distance(1)) {
+                let location = point.location.applying(stroke.transform)
+                let converted = CGPoint(
+                    x: origin.x + (location.x - sourceBounds.minX) * scale,
+                    y: origin.y + (sourceBounds.maxY - location.y) * scale
+                )
+                if isFirst {
+                    path.move(to: converted)
+                    isFirst = false
+                } else {
+                    path.addLine(to: converted)
+                }
+            }
+            // A tap is also a valid ink mark.
+            if path.isEmpty == false {
+                path.addLine(to: CGPoint(x: path.currentPoint.x + 0.01, y: path.currentPoint.y))
+                annotation.add(path)
+            }
+        }
+        page.addAnnotation(annotation)
+        guard let data = document.dataRepresentation() else { throw PDFSigningError.saveFailed }
+        try Task.checkCancellation()
+        do {
+            try FileManager.default.createDirectory(at: outputDirectory, withIntermediateDirectories: true)
+            let destination = outputDirectory.appending(path: UUID().uuidString + ".pdf")
+            try data.write(to: destination, options: .atomic)
+            return destination
+        } catch {
+            throw PDFSigningError.saveFailed
+        }
+    }
+}