(function(window, document) {
"use strict";

// form labels often need unique IDs - this can be used to generate some
window.DllPatcher_uniqueid = 0;
var createID = function() {
    window.DllPatcher_uniqueid++;
    return "dllpatch_" + window.DllPatcher_uniqueid;
}

// Each unique kind of patch should have createUI, validatePatch, applyPatch,
// updateUI

var StandardPatch = function(options) {
    this.name = options.name;
    this.patches = options.patches;
    this.tooltip = options.tooltip;
};

StandardPatch.prototype.createUI = function(parent) {
    var id = createID();
    var label = this.name;
    var patch = $('<div>', {'class' : 'patch'});
    this.checkbox = $('<input type="checkbox" id="' + id + '">')[0];
    patch.append(this.checkbox);
    patch.append('<label for="' + id + '">' + label + '</label>');
    if(this.tooltip) {
        patch.append('<div class="tooltip">' + this.tooltip + '</div>');
    }
    parent.append(patch);
};

StandardPatch.prototype.updateUI = function(file) {
    this.checkbox.checked = this.checkPatchBytes(file) === "on";
};

StandardPatch.prototype.validatePatch = function(file) {
    var status = this.checkPatchBytes(file);
    if(status === "on") {
        console.log('"' + this.name + '"', "is enabled!");
    } else if(status === "off") {
        console.log('"' + this.name + '"', "is disabled!");
    } else {
        return '"' + this.name + '" is neither on nor off! Have you got the right dll?';
    }
};

StandardPatch.prototype.applyPatch = function(file) {
    this.replaceAll(file, this.checkbox.checked);
};

StandardPatch.prototype.replaceAll = function(file, featureOn) {
    for(var i = 0; i < this.patches.length; i++) {
        replace(file, this.patches[i].offset,
                featureOn? this.patches[i].on : this.patches[i].off);
    }
}

StandardPatch.prototype.checkPatchBytes = function(file) {
    var patchStatus = "";
    for(var i = 0; i < this.patches.length; i++) {
        var patch = this.patches[i];
        if(bytesMatch(file, patch.offset, patch.off)) {
            if(patchStatus === "") {
                patchStatus = "off";
            } else if(patchStatus != "off"){
                return "on/off mismatch within patch";
            }
        } else if(bytesMatch(file, patch.offset, patch.on)) {
            if(patchStatus === "") {
                patchStatus = "on";
            } else if(patchStatus != "on"){
                return "on/off mismatch within patch";
            }
        } else {
            return "patch neither on nor off";
        }
    }
    return patchStatus;
}

// Each unique kind of patch should have createUI, validatePatch, applyPatch,
// updateUI

// The DEFAULT state is always the 1st element in the patches array
var UnionPatch = function(options) {
    this.name = options.name;
    this.offset = options.offset;
    this.patches = options.patches;
};

UnionPatch.prototype.createUI = function(parent) {
    this.radios = [];
    var radio_id = createID();

    var container = $("<div>", {"class": "patch-union"});
    container.append('<span class="patch-union-title">' + this.name + ':</span>');
    for(var i = 0; i < this.patches.length; i++) {
        var patch = this.patches[i];
        var id = createID();
        var label = patch.name;
        var patchDiv = $('<div>', {'class' : 'patch'});
        var radio = $('<input type="radio" id="' + id + '" name="' + radio_id + '">')[0];
        this.radios.push(radio);

        patchDiv.append(radio);
        patchDiv.append('<label for="' + id + '">' + label + '</label>');
        if(patch.tooltip) {
            patchDiv.append('<div class="tooltip">' + patch.tooltip + '</div>');
        }
        container.append(patchDiv);
    }
    parent.append(container);
};

UnionPatch.prototype.updateUI = function(file) {
    for(var i = 0; i < this.patches.length; i++) {
        if(bytesMatch(file, this.offset, this.patches[i].patch)) {
            this.radios[i].checked = true;
            return;
        }
    }
    // Default fallback
    this.radios[0].checked = true;
};

UnionPatch.prototype.validatePatch = function(file) {
    for(var i = 0; i < this.patches.length; i++) {
        if(bytesMatch(file, this.offset, this.patches[i].patch)) {
            console.log(this.name, "has", this.patches[i].name, "enabled");
            return;
        }
    }
    return '"' + this.name + '" doesn\'t have a valid patch! Have you got the right dll?';
};

UnionPatch.prototype.applyPatch = function(file) {
    var patch = this.getSelected();
    replace(file, this.offset, patch.patch);
};

UnionPatch.prototype.getSelected = function() {
    for(var i = 0; i < this.patches.length; i++) {
        if(this.radios[i].checked) {
            return this.patches[i];
        }
    }
    return null;
}

var DllPatcherContainer = function (patchers) {
    this.patchers = patchers;
    this.createUI();
};

DllPatcherContainer.prototype.getSupportedDLLs = function () {
    var dlls = [];
    for (var i = 0; i < this.patchers.length; i++) {
        var name = this.patchers[i].filename + ".dll";
        if (dlls.indexOf(name) === -1) {
            dlls.push(name);
        }
    }
    return dlls;
};

DllPatcherContainer.prototype.getSupportedVersions = function () {
    var descriptions = [];
    for (var i = 0; i < this.patchers.length; i++) {
        if ($.type(this.patchers[i].description) === "string") {
            descriptions.push(this.patchers[i].description);
        }
    }
    return descriptions;
};

DllPatcherContainer.prototype.createUI = function () {
    var self = this;
    var container = $("<div>", {"class": "patchContainer"});
    var header = this.getSupportedDLLs().join(", ");
    container.html("<h3>" + header + "</h3>");

    var supportedDlls = $("<ul>");
    var versions = this.getSupportedVersions();
    for (var i = 0; i < versions.length; i++) {
        $("<li>").text(versions[i]).appendTo(supportedDlls);
    }

    $("html").on("dragover dragenter", function () {
        container.addClass("dragover");
        return true;
    })
        .on("dragleave dragend drop", function () {
            container.removeClass("dragover");
            return true;
        })
        .on("dragover dragenter dragleave dragend drop", function (e) {
            e.preventDefault();
        });

    container.on("drop", function (e) {
        var files = e.originalEvent.dataTransfer.files;
        if (files && files.length > 0)
            self.loadFile(files[0]);
    });

    this.fileInput = $("<input>",
        {
            "class": "fileInput",
            "id": "any-file",
            "type": "file",
        });
    var label = $("<label>", {"class": "fileLabel", "for": "any-file"});
    label.html("<strong>Choose a file</strong> or drag and drop.");

    this.fileInput.on("change", function (e) {
        if (this.files && this.files.length > 0)
            self.loadFile(this.files[0]);
    });

    this.successDiv = $("<div>", {"class": "success"});
    this.errorDiv = $("<div>", {"class": "error"});

    container.append(this.fileInput);
    container.append(label);

    if (versions.length > 0) {
        $("<h4>Supported Versions</h4>").appendTo(container);
    }
    container.append(supportedDlls);
    container.append(this.successDiv);
    container.append(this.errorDiv);
    $("body").append(container);
};

DllPatcherContainer.prototype.loadFile = function (file) {
    var reader = new FileReader();
    var self = this;

    reader.onload = function (e) {
        var found = false;
        // clear logs
        self.errorDiv.empty();
        self.successDiv.empty();
        for (var i = 0; i < self.patchers.length; i++) {
            var patcher = self.patchers[i];
            // remove the previous UI to clear the page
            patcher.destroyUI();
            // patcher UI elements have to exist to load the file
            patcher.createUI();
            patcher.container.hide();
            patcher.loadBuffer(e.target.result);
            if (patcher.validatePatches()) {
                found = true;
                patcher.loadPatchUI();
                patcher.updatePatchUI();
                patcher.container.show();
                var successStr = patcher.filename + ".dll"
                if ($.type(this.description) === "string") {
                    successStr += "(" + patcher.description + ")";
                }
                self.successDiv.html(successStr + " loaded successfully!");
            }
        }

        if (!found) {
            self.errorDiv.html("No patches found matching the given DLL.");
        }
    };

    reader.readAsArrayBuffer(file);
};

var DllPatcher = function(fname, args, description) {
    this.mods = [];
    for(var i = 0; i < args.length; i++) {
        var mod = args[i];
        if(mod.type) {
            if(mod.type === "union") {
                this.mods.push(new UnionPatch(mod));
            }
        } else { // standard patch
            this.mods.push(new StandardPatch(mod));
        }
    }

    this.filename = fname;
    this.description = description;
    this.multiPatcher = true;

    if (!this.description) {
        // old style patcher, use the old method to generate the UI
        this.multiPatcher = false;
        this.createUI();
        this.loadPatchUI();
    }
};

DllPatcher.prototype.createUI = function() {
    var self = this;
    this.container = $("<div>", {"class": "patchContainer"});
    var header = this.filename + '.dll';
    if($.type(this.description) === "string") {
        header += ' (' + this.description + ')';
    }
    this.container.html('<h3>' + header + '</h3>');

    this.successDiv = $("<div>", {"class": "success"});
    this.errorDiv = $("<div>", {"class": "error"});
    this.patchDiv = $("<div>", {"class": "patches"});

    var saveButton = $("<button disabled>");
    saveButton.text('Load DLL First');
    saveButton.on('click', this.saveDll.bind(this));
    this.saveButton = saveButton;

    if (!this.multiPatcher) {
        $('html').on('dragover dragenter', function() {
            self.container.addClass('dragover');
            return true;
        })
        .on('dragleave dragend drop', function() {
            self.container.removeClass('dragover');
            return true;
        })
        .on('dragover dragenter dragleave dragend drop', function(e) {
            e.preventDefault();
        });

        this.container.on('drop', function(e) {
            var files = e.originalEvent.dataTransfer.files;
            if(files && files.length > 0)
                self.loadFile(files[0]);
        })

        this.fileInput = $("<input>",
            {"class": "fileInput",
             "id" : this.filename + '-file',
             "type" : 'file'});
        var label = $("<label>", {"class": "fileLabel", "for": this.filename + '-file'});
        label.html('<strong>Choose a file</strong> or drag and drop.');

        this.fileInput.on('change', function(e) {
            if(this.files && this.files.length > 0)
                self.loadFile(this.files[0]);
        });

        this.container.append(this.fileInput);
        this.container.append(label);
    }

    this.container.append(this.successDiv);
    this.container.append(this.errorDiv);
    this.container.append(this.patchDiv);
    this.container.append(saveButton);
    $("body").append(this.container);
}

DllPatcher.prototype.destroyUI = function () {
    if (this.hasOwnProperty("container"))
        this.container.remove();
};

DllPatcher.prototype.loadBuffer = function(buffer) {
    this.dllFile = new Uint8Array(buffer);
    if(this.validatePatches()) {
        this.successDiv.removeClass("hidden");
        this.successDiv.html("DLL loaded successfully!");
    } else {
        this.successDiv.addClass("hidden");
    }
    // Update save button regardless
    this.saveButton.prop('disabled', false);
    this.saveButton.text('Save DLL');
    this.errorDiv.html(this.errorLog);
}

DllPatcher.prototype.loadFile = function(file) {
    var reader = new FileReader();
    var self = this;

    reader.onload = function(e) {
        self.loadBuffer(e.target.result);
        self.updatePatchUI();
    };

    reader.readAsArrayBuffer(file);
};

DllPatcher.prototype.saveDll = function() {
    if(!this.dllFile || !this.mods || !this.filename)
        return;
    var fname = this.filename;

    for(var i = 0; i < this.mods.length; i++) {
        this.mods[i].applyPatch(this.dllFile);
    }
    fname += '.dll';

    var blob = new Blob([this.dllFile], {type: "application/octet-stream"});
    saveAs(blob, fname);
}

DllPatcher.prototype.loadPatchUI = function() {
    for(var i = 0; i < this.mods.length; i++) {
        this.mods[i].createUI(this.patchDiv);
    }
}

DllPatcher.prototype.updatePatchUI = function() {
    for(var i = 0; i < this.mods.length; i++) {
        this.mods[i].updateUI(this.dllFile);
    }
}

DllPatcher.prototype.validatePatches = function() {
    this.errorLog = "";
    var success = true;
    for(var i = 0; i < this.mods.length; i++) {
        var error = this.mods[i].validatePatch(this.dllFile);
        if(error) {
            this.errorLog += error + "<br/>";
            success = false;
        }
    }
    return success;
}

var bytesMatch = function(buffer, offset, bytes) {
    for(var i = 0; i < bytes.length; i++) {
        if(buffer[offset+i] != bytes[i])
            return false;
    }
    return true;
};

var replace = function(buffer, offset, bytes) {
    for(var i = 0; i < bytes.length; i++) {
        buffer[offset+i] = bytes[i];
    }
}

var whichBytesMatch = function(buffer, offset, bytesArray) {
    for(var i = 0; i < bytesArray.length; i++) {
        if(bytesMatch(buffer, offset, bytesArray[i]))
            return i;
    }
    return -1;
}

window.DllPatcher = DllPatcher;
window.DllPatcherContainer = DllPatcherContainer;

})(window, document);