WP-2: PDF composer + PageLayout per SPEC-A1b (two-pass, atomic write, zero annotations)

2026-08-31 14:42:00 +04:00
parent 97d21be470
commit 1b5816aa38
3 changed files with 937 additions and 0 deletions
@@ -0,0 +1,209 @@
+import AppKit
+import CoreGraphics
+import CoreText
+import Foundation
+import ImageIO
+import os
+
+private let pdfLog = Logger(subsystem: "ai.flowmaster.shotdeck", category: "PDF")
+
+public struct PDFComposer: Sendable {
+    public init() {}
+
+    @discardableResult
+    public func compose(
+        session: CaptureSession,
+        imageURL: (Capture) -> URL,
+        title: String,
+        to outputURL: URL
+    ) throws -> Int {
+        if session.isEmpty {
+            throw ShotdeckError.pdfCompositionFailed(reason: "session has no captures")
+        }
+
+        var loaded: [(Capture, CGImage)] = []
+        loaded.reserveCapacity(session.captures.count)
+        for capture in session.captures {
+            let url = imageURL(capture)
+            if let image = Self.loadCGImage(from: url) {
+                loaded.append((capture, image))
+            } else {
+                pdfLog.error(
+                    "skipping capture \(capture.id.uuidString, privacy: .public) seq \(capture.sequence, privacy: .public): image unreadable at \(url.path, privacy: .public)"
+                )
+            }
+        }
+
+        guard !loaded.isEmpty else {
+            throw ShotdeckError.pdfCompositionFailed(reason: "no readable images in session")
+        }
+
+        let pageCount = loaded.count
+        let tmpURL = outputURL
+            .deletingLastPathComponent()
+            .appendingPathComponent(".tmp-\(UUID().uuidString)-\(outputURL.lastPathComponent)")
+
+        do {
+            try Self.writePDF(
+                loaded: loaded,
+                pageCount: pageCount,
+                title: title,
+                sessionID: session.id,
+                to: tmpURL
+            )
+
+            let handle = try FileHandle(forWritingTo: tmpURL)
+            try handle.synchronize()
+            try handle.close()
+
+            if FileManager.default.fileExists(atPath: outputURL.path) {
+                try FileManager.default.removeItem(at: outputURL)
+            }
+            try FileManager.default.moveItem(at: tmpURL, to: outputURL)
+            return pageCount
+        } catch {
+            try? FileManager.default.removeItem(at: tmpURL)
+            if let shotdeck = error as? ShotdeckError {
+                throw shotdeck
+            }
+            throw ShotdeckError.pdfCompositionFailed(reason: error.localizedDescription)
+        }
+    }
+
+    public static func fileName(for session: CaptureSession) -> String {
+        "Shotdeck-\(DubaiTime.fileStamp(session.createdAt)).pdf"
+    }
+
+    private static func writePDF(
+        loaded: [(Capture, CGImage)],
+        pageCount: Int,
+        title: String,
+        sessionID: UUID,
+        to tmpURL: URL
+    ) throws {
+        guard let consumer = CGDataConsumer(url: tmpURL as CFURL) else {
+            throw ShotdeckError.pdfCompositionFailed(reason: "cannot open output location")
+        }
+
+        let auxiliaryInfo: [String: Any] = [
+            kCGPDFContextCreator as String: "Shotdeck",
+            kCGPDFContextTitle as String: title,
+            kCGPDFContextSubject as String: sessionID.uuidString.lowercased(),
+        ]
+
+        guard let context = CGContext(
+            consumer: consumer,
+            mediaBox: nil,
+            auxiliaryInfo as CFDictionary
+        ) else {
+            throw ShotdeckError.pdfCompositionFailed(reason: "cannot open output location")
+        }
+
+        let lightGrey = CGColor(gray: 0.75, alpha: 1)
+        let black = CGColor(gray: 0, alpha: 1)
+        let timestampColor = CGColor(gray: 0.45, alpha: 1)
+
+        for pageIndex in 1...pageCount {
+            let (capture, cgImage) = loaded[pageIndex - 1]
+            let layout = PageLayout(capture: capture, pageIndex: pageIndex, pageCount: pageCount)
+
+            context.beginPDFPage(Self.pageInfo(mediaBox: layout.pageRect))
+
+            context.draw(cgImage, in: layout.imageRect)
+
+            context.setStrokeColor(lightGrey)
+            context.setLineWidth(0.5)
+            context.move(to: CGPoint(x: layout.headerRect.minX, y: layout.headerRect.minY))
+            context.addLine(to: CGPoint(x: layout.headerRect.maxX, y: layout.headerRect.minY))
+            context.strokePath()
+
+            drawText(
+                layout.pageNumberText,
+                font: layout.pageNumberFont,
+                color: black,
+                at: layout.pageNumberOrigin,
+                in: context
+            )
+            drawText(
+                layout.timestampText,
+                font: layout.timestampFont,
+                color: timestampColor,
+                at: layout.timestampOrigin,
+                in: context
+            )
+            drawText(
+                "PASS",
+                font: layout.tickLabelFont,
+                color: black,
+                at: layout.passLabelOrigin,
+                in: context
+            )
+            drawText(
+                "FAIL",
+                font: layout.tickLabelFont,
+                color: black,
+                at: layout.failLabelOrigin,
+                in: context
+            )
+
+            strokeTickBox(layout.passTickBox, in: context, color: black)
+            strokeTickBox(layout.failTickBox, in: context, color: black)
+
+            context.endPDFPage()
+        }
+
+        context.closePDF()
+    }
+
+    private static func pageInfo(mediaBox: CGRect) -> CFDictionary {
+        var box = mediaBox
+        let data = Data(bytes: &box, count: MemoryLayout<CGRect>.size)
+        return [kCGPDFContextMediaBox as String: data] as CFDictionary
+    }
+
+    private static func drawText(
+        _ string: String,
+        font: NSFont,
+        color: CGColor,
+        at origin: CGPoint,
+        in context: CGContext
+    ) {
+        let attributes: [CFString: Any] = [
+            kCTFontAttributeName: font,
+            kCTForegroundColorAttributeName: color,
+        ]
+        guard let attributed = CFAttributedStringCreate(
+            nil,
+            string as CFString,
+            attributes as CFDictionary
+        ) else {
+            return
+        }
+        let line = CTLineCreateWithAttributedString(attributed)
+        context.textMatrix = .identity
+        context.textPosition = origin
+        CTLineDraw(line, context)
+    }
+
+    private static func strokeTickBox(_ box: CGRect, in context: CGContext, color: CGColor) {
+        let path = CGPath(
+            roundedRect: box,
+            cornerWidth: 2,
+            cornerHeight: 2,
+            transform: nil
+        )
+        context.addPath(path)
+        context.setStrokeColor(color)
+        context.setLineWidth(1.0)
+        context.strokePath()
+    }
+
+    private static func loadCGImage(from url: URL) -> CGImage? {
+        guard let source = CGImageSourceCreateWithURL(url as CFURL, nil),
+              CGImageSourceGetCount(source) > 0
+        else {
+            return nil
+        }
+        return CGImageSourceCreateImageAtIndex(source, 0, nil)
+    }
+}