#target photoshop

/*
  Export art layers with optional scope, format and trimming settings.
  - Can export every art layer or only layers currently visible (including parent visibility).
  - Supports PNG and JPEG with adjustable JPEG quality (0-100).
  - Can keep the full document canvas or trim transparent edges for each layer.
  - Does not add prefixes or four-digit sequence numbers.
  - Works on a duplicate, so the source document and its visibility states stay unchanged.
  - Nested art layers are supported; layer groups themselves are not exported.
*/

(function () {
    if (app.documents.length === 0) {
        alert("请先打开一个 PSD/PSB 文档。");
        return;
    }

    function pad2(value) {
        return value < 10 ? "0" + value : String(value);
    }

    function timeStamp() {
        var now = new Date();
        return now.getFullYear() +
            pad2(now.getMonth() + 1) +
            pad2(now.getDate()) + "_" +
            pad2(now.getHours()) +
            pad2(now.getMinutes()) +
            pad2(now.getSeconds());
    }

    function safeName(name) {
        var value = String(name);
        value = value.replace(/\.(png|jpe?g)$/i, "");
        value = value.replace(/[\\\/:*?"<>|]/g, "_");
        value = value.replace(/^\s+|\s+$/g, "");
        value = value.replace(/[\. ]+$/g, "");
        return value.length > 0 ? value : "unnamed_layer";
    }

    function showOptionsDialog() {
        var dialog = new Window("dialog", "图层导出选项");
        dialog.orientation = "column";
        dialog.alignChildren = "fill";

        var scopePanel = dialog.add("panel", undefined, "导出范围");
        scopePanel.orientation = "column";
        scopePanel.alignChildren = "left";
        scopePanel.margins = 12;
        var visibleOnly = scopePanel.add("checkbox", undefined, "仅导出当前可见图层");
        visibleOnly.value = true;
        scopePanel.add("statictext", undefined, "未勾选时导出所有普通图层");

        var formatPanel = dialog.add("panel", undefined, "文件格式");
        formatPanel.orientation = "column";
        formatPanel.alignChildren = "left";
        formatPanel.margins = 12;

        var formatChoices = formatPanel.add("group");
        formatChoices.orientation = "row";
        var pngRadio = formatChoices.add("radiobutton", undefined, "PNG");
        var jpegRadio = formatChoices.add("radiobutton", undefined, "JPEG");
        pngRadio.value = true;

        var qualityGroup = formatPanel.add("group");
        qualityGroup.orientation = "row";
        qualityGroup.alignChildren = ["left", "center"];
        var qualityLabel = qualityGroup.add("statictext", undefined, "JPEG 质量：");
        var qualitySlider = qualityGroup.add("slider", undefined, 90, 0, 100);
        qualitySlider.preferredSize.width = 180;
        var qualityValue = qualityGroup.add("statictext", undefined, "90");
        qualityValue.characters = 3;

        function setQualityEnabled(enabled) {
            qualityLabel.enabled = enabled;
            qualitySlider.enabled = enabled;
            qualityValue.enabled = enabled;
        }

        qualitySlider.onChanging = function () {
            qualityValue.text = String(Math.round(qualitySlider.value));
        };
        qualitySlider.onChange = qualitySlider.onChanging;
        pngRadio.onClick = function () {
            setQualityEnabled(false);
        };
        jpegRadio.onClick = function () {
            setQualityEnabled(true);
        };
        setQualityEnabled(false);

        var trimPanel = dialog.add("panel", undefined, "画布");
        trimPanel.orientation = "column";
        trimPanel.alignChildren = "left";
        trimPanel.margins = 12;
        var trimOutput = trimPanel.add("checkbox", undefined, "导出时裁切透明边缘");
        trimOutput.value = true;
        trimPanel.add("statictext", undefined, "未勾选时保留原文档画布尺寸");

        var buttons = dialog.add("group");
        buttons.alignment = "right";
        buttons.add("button", undefined, "取消", {name: "cancel"});
        buttons.add("button", undefined, "继续", {name: "ok"});

        if (dialog.show() !== 1) {
            return null;
        }

        return {
            visibleOnly: visibleOnly.value,
            format: jpegRadio.value ? "jpeg" : "png",
            jpegQuality: Math.round(qualitySlider.value),
            trim: trimOutput.value
        };
    }

    function collectArtLayers(container, result) {
        for (var i = 0; i < container.layers.length; i++) {
            var layer = container.layers[i];
            if (layer.typename === "ArtLayer") {
                result.push(layer);
            } else if (layer.typename === "LayerSet") {
                collectArtLayers(layer, result);
            }
        }
    }

    function isEffectivelyVisible(layer) {
        if (!layer.visible) {
            return false;
        }

        var parent = layer.parent;
        while (parent && parent.typename === "LayerSet") {
            if (!parent.visible) {
                return false;
            }
            parent = parent.parent;
        }
        return true;
    }

    function hideAllArtLayers(layers) {
        for (var i = 0; i < layers.length; i++) {
            try {
                layers[i].visible = false;
            } catch (ignore) {}
        }
    }

    function showLayerAndParents(layer) {
        layer.visible = true;
        var parent = layer.parent;
        while (parent && parent.typename === "LayerSet") {
            parent.visible = true;
            parent = parent.parent;
        }
    }

    function createUniqueOutputFolder(parent, documentName, formatLabel) {
        var baseName = safeName(documentName.replace(/\.[^\.]+$/, "")) + "_" + formatLabel;
        var folder = new Folder(parent.fsName + "/" + baseName);
        if (folder.exists) {
            folder = new Folder(parent.fsName + "/" + baseName + "_" + timeStamp());
        }
        if (!folder.create()) {
            throw new Error("无法创建输出文件夹：" + folder.fsName);
        }
        return folder;
    }

    function createExportOptions(format, jpegQuality) {
        var exportOptions = new ExportOptionsSaveForWeb();
        exportOptions.includeProfile = false;

        if (format === "jpeg") {
            exportOptions.format = SaveDocumentType.JPEG;
            exportOptions.quality = jpegQuality;
            exportOptions.optimized = true;
        } else {
            exportOptions.format = SaveDocumentType.PNG;
            exportOptions.PNG8 = false;
            exportOptions.transparency = true;
            exportOptions.interlaced = false;
        }

        return exportOptions;
    }

    var sourceDoc = app.activeDocument;
    var settings = showOptionsDialog();
    if (settings === null) {
        return;
    }

    var formatLabel = settings.format === "jpeg" ? "JPEG" : "PNG";
    var extension = settings.format === "jpeg" ? ".jpg" : ".png";
    var parentFolder = Folder.selectDialog("选择 " + formatLabel + " 导出目录");
    if (parentFolder === null) {
        return;
    }

    var oldDialogs = app.displayDialogs;
    var workDoc = null;

    try {
        app.displayDialogs = DialogModes.NO;
        workDoc = sourceDoc.duplicate();
        app.activeDocument = workDoc;

        var allLayers = [];
        var layers = [];
        collectArtLayers(workDoc, allLayers);

        for (var i = 0; i < allLayers.length; i++) {
            if (!settings.visibleOnly || isEffectivelyVisible(allLayers[i])) {
                layers.push(allLayers[i]);
            }
        }

        if (layers.length === 0) {
            if (settings.visibleOnly) {
                throw new Error("文档中没有当前可见的普通图层。");
            }
            throw new Error("文档中没有可导出的普通图层。");
        }

        var outputFolder = createUniqueOutputFolder(parentFolder, sourceDoc.name, formatLabel);
        var exportOptions = createExportOptions(settings.format, settings.jpegQuality);

        var usedNames = {};
        hideAllArtLayers(allLayers);

        for (i = 0; i < layers.length; i++) {
            hideAllArtLayers(allLayers);
            showLayerAndParents(layers[i]);

            var baseName = safeName(layers[i].name);
            var key = baseName.toLowerCase();
            if (usedNames[key] === undefined) {
                usedNames[key] = 1;
            } else {
                usedNames[key]++;
                baseName += "_" + usedNames[key];
            }

            var preTrimState = null;
            if (settings.trim) {
                preTrimState = workDoc.activeHistoryState;
                try {
                    workDoc.trim(TrimType.TRANSPARENT, true, true, true, true);
                } catch (ignoreTrim) {
                    // Empty/adjustment-only layers may not contain trim-able pixels.
                }
            }

            var outputFile = new File(outputFolder.fsName + "/" + baseName + extension);
            workDoc.exportDocument(outputFile, ExportType.SAVEFORWEB, exportOptions);

            if (preTrimState !== null) {
                try {
                    workDoc.activeHistoryState = preTrimState;
                } catch (ignoreHistory) {}
            }
        }

        workDoc.close(SaveOptions.DONOTSAVECHANGES);
        workDoc = null;
        app.activeDocument = sourceDoc;
        app.displayDialogs = oldDialogs;

        alert(
            "导出完成：" + layers.length + " 个 " + formatLabel + "\n\n" +
            "范围 = " + (settings.visibleOnly ? "仅当前可见图层" : "所有普通图层") + "\n" +
            (settings.format === "jpeg" ? "JPEG 质量 = " + settings.jpegQuality + "\n" : "") +
            "文件名 = 图层名\n" +
            "尺寸 = " + (settings.trim ? "已裁切透明边缘" : "原文档画布尺寸") + "\n\n" +
            "输出目录：\n" + outputFolder.fsName
        );
    } catch (error) {
        if (workDoc !== null) {
            try {
                workDoc.close(SaveOptions.DONOTSAVECHANGES);
            } catch (ignoreClose) {}
        }
        try {
            app.activeDocument = sourceDoc;
        } catch (ignoreActivate) {}
        app.displayDialogs = oldDialogs;
        alert("导出失败：\n" + error.message);
    }
}());