import { dict, unreachable, Stack, DictSet } from '@glimmer/util';
import { Ops, isFlushElement, isArgument, isAttribute, isAttrSplat } from '@glimmer/wire-format';
import { isLiteral, SyntaxError, preprocess } from '@glimmer/syntax';

class SymbolTable {
    static top() {
        return new ProgramSymbolTable();
    }
    child(locals) {
        let symbols = locals.map(name => this.allocate(name));
        return new BlockSymbolTable(this, locals, symbols);
    }
}
class ProgramSymbolTable extends SymbolTable {
    constructor() {
        super(...arguments);
        this.symbols = [];
        this.size = 1;
        this.named = dict();
        this.blocks = dict();
    }
    has(_name) {
        return false;
    }
    get(_name) {
        throw unreachable();
    }
    getLocalsMap() {
        return {};
    }
    getEvalInfo() {
        return [];
    }
    allocateNamed(name) {
        let named = this.named[name];
        if (!named) {
            named = this.named[name] = this.allocate(name);
        }
        return named;
    }
    allocateBlock(name) {
        let block = this.blocks[name];
        if (!block) {
            block = this.blocks[name] = this.allocate(`&${name}`);
        }
        return block;
    }
    allocate(identifier) {
        this.symbols.push(identifier);
        return this.size++;
    }
}
class BlockSymbolTable extends SymbolTable {
    constructor(parent, symbols, slots) {
        super();
        this.parent = parent;
        this.symbols = symbols;
        this.slots = slots;
    }
    has(name) {
        return this.symbols.indexOf(name) !== -1 || this.parent.has(name);
    }
    get(name) {
        let slot = this.symbols.indexOf(name);
        return slot === -1 ? this.parent.get(name) : this.slots[slot];
    }
    getLocalsMap() {
        let dict$$1 = this.parent.getLocalsMap();
        this.symbols.forEach(symbol => dict$$1[symbol] = this.get(symbol));
        return dict$$1;
    }
    getEvalInfo() {
        let locals = this.getLocalsMap();
        return Object.keys(locals).map(symbol => locals[symbol]);
    }
    allocateNamed(name) {
        return this.parent.allocateNamed(name);
    }
    allocateBlock(name) {
        return this.parent.allocateBlock(name);
    }
    allocate(identifier) {
        return this.parent.allocate(identifier);
    }
}
/**
 * Takes in an AST and outputs a list of actions to be consumed
 * by a compiler. For example, the template
 *
 *     foo{{bar}}<div>baz</div>
 *
 * produces the actions
 *
 *     [['startProgram', [programNode, 0]],
 *      ['text', [textNode, 0, 3]],
 *      ['mustache', [mustacheNode, 1, 3]],
 *      ['openElement', [elementNode, 2, 3, 0]],
 *      ['text', [textNode, 0, 1]],
 *      ['closeElement', [elementNode, 2, 3],
 *      ['endProgram', [programNode]]]
 *
 * This visitor walks the AST depth first and backwards. As
 * a result the bottom-most child template will appear at the
 * top of the actions list whereas the root template will appear
 * at the bottom of the list. For example,
 *
 *     <div>{{#if}}foo{{else}}bar<b></b>{{/if}}</div>
 *
 * produces the actions
 *
 *     [['startProgram', [programNode, 0]],
 *      ['text', [textNode, 0, 2, 0]],
 *      ['openElement', [elementNode, 1, 2, 0]],
 *      ['closeElement', [elementNode, 1, 2]],
 *      ['endProgram', [programNode]],
 *      ['startProgram', [programNode, 0]],
 *      ['text', [textNode, 0, 1]],
 *      ['endProgram', [programNode]],
 *      ['startProgram', [programNode, 2]],
 *      ['openElement', [elementNode, 0, 1, 1]],
 *      ['block', [blockNode, 0, 1]],
 *      ['closeElement', [elementNode, 0, 1]],
 *      ['endProgram', [programNode]]]
 *
 * The state of the traversal is maintained by a stack of frames.
 * Whenever a node with children is entered (either a ProgramNode
 * or an ElementNode) a frame is pushed onto the stack. The frame
 * contains information about the state of the traversal of that
 * node. For example,
 *
 *   - index of the current child node being visited
 *   - the number of mustaches contained within its child nodes
 *   - the list of actions generated by its child nodes
 */
class Frame {
    constructor() {
        this.parentNode = null;
        this.children = null;
        this.childIndex = null;
        this.childCount = null;
        this.childTemplateCount = 0;
        this.mustacheCount = 0;
        this.actions = [];
        this.blankChildTextNodes = null;
        this.symbols = null;
    }
}
class TemplateVisitor {
    constructor() {
        this.frameStack = [];
        this.actions = [];
        this.programDepth = -1;
    }
    visit(node) {
        this[node.type](node);
    }
    // Traversal methods
    Program(program) {
        this.programDepth++;
        let parentFrame = this.getCurrentFrame();
        let programFrame = this.pushFrame();
        if (!parentFrame) {
            program['symbols'] = SymbolTable.top();
        } else {
            program['symbols'] = parentFrame.symbols.child(program.blockParams);
        }
        let startType, endType;
        if (this.programDepth === 0) {
            startType = 'startProgram';
            endType = 'endProgram';
        } else {
            startType = 'startBlock';
            endType = 'endBlock';
        }
        programFrame.parentNode = program;
        programFrame.children = program.body;
        programFrame.childCount = program.body.length;
        programFrame.blankChildTextNodes = [];
        programFrame.actions.push([endType, [program, this.programDepth]]);
        programFrame.symbols = program['symbols'];
        for (let i = program.body.length - 1; i >= 0; i--) {
            programFrame.childIndex = i;
            this.visit(program.body[i]);
        }
        programFrame.actions.push([startType, [program, programFrame.childTemplateCount, programFrame.blankChildTextNodes.reverse()]]);
        this.popFrame();
        this.programDepth--;
        // Push the completed template into the global actions list
        if (parentFrame) {
            parentFrame.childTemplateCount++;
        }
        this.actions.push(...programFrame.actions.reverse());
    }
    ElementNode(element) {
        let parentFrame = this.currentFrame;
        let elementFrame = this.pushFrame();
        elementFrame.parentNode = element;
        elementFrame.children = element.children;
        elementFrame.childCount = element.children.length;
        elementFrame.mustacheCount += element.modifiers.length;
        elementFrame.blankChildTextNodes = [];
        elementFrame.symbols = element['symbols'] = parentFrame.symbols.child(element.blockParams);
        let actionArgs = [element, parentFrame.childIndex, parentFrame.childCount];
        elementFrame.actions.push(['closeElement', actionArgs]);
        for (let i = element.attributes.length - 1; i >= 0; i--) {
            this.visit(element.attributes[i]);
        }
        for (let i = element.children.length - 1; i >= 0; i--) {
            elementFrame.childIndex = i;
            this.visit(element.children[i]);
        }
        let open = ['openElement', [...actionArgs, elementFrame.mustacheCount, elementFrame.blankChildTextNodes.reverse()]];
        elementFrame.actions.push(open);
        this.popFrame();
        // Propagate the element's frame state to the parent frame
        if (elementFrame.mustacheCount > 0) {
            parentFrame.mustacheCount++;
        }
        parentFrame.childTemplateCount += elementFrame.childTemplateCount;
        parentFrame.actions.push(...elementFrame.actions);
    }
    AttrNode(attr) {
        if (attr.value.type !== 'TextNode') {
            this.currentFrame.mustacheCount++;
        }
    }
    TextNode(text) {
        let frame = this.currentFrame;
        if (text.chars === '') {
            frame.blankChildTextNodes.push(domIndexOf(frame.children, text));
        }
        frame.actions.push(['text', [text, frame.childIndex, frame.childCount]]);
    }
    BlockStatement(node) {
        let frame = this.currentFrame;
        frame.mustacheCount++;
        frame.actions.push(['block', [node, frame.childIndex, frame.childCount]]);
        if (node.inverse) {
            this.visit(node.inverse);
        }
        if (node.program) {
            this.visit(node.program);
        }
    }
    PartialStatement(node) {
        let frame = this.currentFrame;
        frame.mustacheCount++;
        frame.actions.push(['mustache', [node, frame.childIndex, frame.childCount]]);
    }
    CommentStatement(text) {
        let frame = this.currentFrame;
        frame.actions.push(['comment', [text, frame.childIndex, frame.childCount]]);
    }
    MustacheCommentStatement() {
        // Intentional empty: Handlebars comments should not affect output.
    }
    MustacheStatement(mustache) {
        let frame = this.currentFrame;
        frame.mustacheCount++;
        frame.actions.push(['mustache', [mustache, frame.childIndex, frame.childCount]]);
    }
    // Frame helpers
    get currentFrame() {
        return this.getCurrentFrame();
    }
    getCurrentFrame() {
        return this.frameStack[this.frameStack.length - 1];
    }
    pushFrame() {
        let frame = new Frame();
        this.frameStack.push(frame);
        return frame;
    }
    popFrame() {
        return this.frameStack.pop();
    }
}
// Returns the index of `domNode` in the `nodes` array, skipping
// over any nodes which do not represent DOM nodes.
function domIndexOf(nodes, domNode) {
    let index = -1;
    for (let i = 0; i < nodes.length; i++) {
        let node = nodes[i];
        if (node.type !== 'TextNode' && node.type !== 'ElementNode') {
            continue;
        } else {
            index++;
        }
        if (node === domNode) {
            return index;
        }
    }
    return -1;
}

class Block {
    constructor() {
        this.statements = [];
    }
    push(statement) {
        this.statements.push(statement);
    }
}
class InlineBlock extends Block {
    constructor(table) {
        super();
        this.table = table;
    }
    toJSON() {
        return {
            statements: this.statements,
            parameters: this.table.slots
        };
    }
}
class TemplateBlock extends Block {
    constructor(symbolTable) {
        super();
        this.symbolTable = symbolTable;
        this.type = 'template';
        this.yields = new DictSet();
        this.named = new DictSet();
        this.blocks = [];
        this.hasEval = false;
    }
    push(statement) {
        this.statements.push(statement);
    }
    toJSON() {
        return {
            symbols: this.symbolTable.symbols,
            statements: this.statements,
            hasEval: this.hasEval
        };
    }
}
class ComponentBlock extends Block {
    constructor(tag, table, selfClosing) {
        super();
        this.tag = tag;
        this.table = table;
        this.selfClosing = selfClosing;
        this.attributes = [];
        this.arguments = [];
        this.inParams = true;
        this.positionals = [];
    }
    push(statement) {
        if (this.inParams) {
            if (isFlushElement(statement)) {
                this.inParams = false;
            } else if (isArgument(statement)) {
                this.arguments.push(statement);
            } else if (isAttribute(statement)) {
                this.attributes.push(statement);
            } else if (isAttrSplat(statement)) {
                this.attributes.push(statement);
            } else {
                throw new Error('Compile Error: only parameters allowed before flush-element');
            }
        } else {
            this.statements.push(statement);
        }
    }
    toJSON() {
        let args = this.arguments;
        let keys = args.map(arg => arg[1]);
        let values = args.map(arg => arg[2]);
        let block = this.selfClosing ? null : {
            statements: this.statements,
            parameters: this.table.slots
        };
        return [this.tag, this.attributes, [keys, values], block];
    }
}
class Template {
    constructor(symbols) {
        this.block = new TemplateBlock(symbols);
    }
    toJSON() {
        return this.block.toJSON();
    }
}
class JavaScriptCompiler {
    constructor(opcodes, symbols, options) {
        this.blocks = new Stack();
        this.values = [];
        this.opcodes = opcodes;
        this.template = new Template(symbols);
        this.options = options;
    }
    static process(opcodes, symbols, options) {
        let compiler = new JavaScriptCompiler(opcodes, symbols, options);
        return compiler.process();
    }
    get currentBlock() {
        return this.blocks.current;
    }
    process() {
        this.opcodes.forEach(op => {
            let opcode = op[0];
            let arg = op[1];
            if (!this[opcode]) {
                throw new Error(`unimplemented ${opcode} on JavaScriptCompiler`);
            }
            this[opcode](arg);
        });
        return this.template;
    }
    /// Nesting
    startBlock(program) {
        let block = new InlineBlock(program['symbols']);
        this.blocks.push(block);
    }
    endBlock() {
        let { template, blocks } = this;
        let block = blocks.pop();
        template.block.blocks.push(block.toJSON());
    }
    startProgram() {
        this.blocks.push(this.template.block);
    }
    endProgram() {}
    /// Statements
    text(content) {
        this.push([Ops.Text, content]);
    }
    append(trusted) {
        this.push([Ops.Append, this.popValue(), trusted]);
    }
    comment(value) {
        this.push([Ops.Comment, value]);
    }
    modifier(name) {
        let params = this.popValue();
        let hash = this.popValue();
        this.push([Ops.Modifier, name, params, hash]);
    }
    block([name, template, inverse]) {
        let params = this.popValue();
        let hash = this.popValue();
        let blocks = this.template.block.blocks;

        this.push([Ops.Block, name, params, hash, blocks[template], blocks[inverse]]);
    }
    openComponent(element) {
        let tag = this.options && this.options.customizeComponentName ? this.options.customizeComponentName(element.tag) : element.tag;
        let component = new ComponentBlock(tag, element['symbols'], element.selfClosing);
        this.blocks.push(component);
    }
    openSplattedElement(element) {
        let tag = element.tag;
        if (element.blockParams.length > 0) {
            throw new Error(`Compile Error: <${element.tag}> is not a component and doesn't support block parameters`);
        } else {
            this.push([Ops.OpenSplattedElement, tag]);
        }
    }
    openElement(element) {
        let tag = element.tag;
        if (element.blockParams.length > 0) {
            throw new Error(`Compile Error: <${element.tag}> is not a component and doesn't support block parameters`);
        } else {
            this.push([Ops.OpenElement, tag]);
        }
    }
    flushElement() {
        this.push([Ops.FlushElement]);
    }
    closeComponent(_element) {
        if (_element.modifiers.length > 0) {
            throw new Error('Compile Error: Element modifiers are not allowed in components');
        }
        let [tag, attrs, args, block] = this.endComponent();
        this.push([Ops.Component, tag, attrs, args, block]);
    }
    closeDynamicComponent(_element) {
        let [, attrs, args, block] = this.endComponent();
        this.push([Ops.DynamicComponent, this.popValue(), attrs, args, block]);
    }
    closeElement(_element) {
        this.push([Ops.CloseElement]);
    }
    staticAttr([name, namespace]) {
        let value = this.popValue();
        this.push([Ops.StaticAttr, name, value, namespace]);
    }
    dynamicAttr([name, namespace]) {
        let value = this.popValue();
        this.push([Ops.DynamicAttr, name, value, namespace]);
    }
    trustingAttr([name, namespace]) {
        let value = this.popValue();
        this.push([Ops.TrustingAttr, name, value, namespace]);
    }
    staticArg(name) {
        let value = this.popValue();
        this.push([Ops.StaticArg, name, value]);
    }
    dynamicArg(name) {
        let value = this.popValue();
        this.push([Ops.DynamicArg, name, value]);
    }
    yield(to) {
        let params = this.popValue();
        this.push([Ops.Yield, to, params]);
    }
    attrSplat(to) {
        this.push([Ops.AttrSplat, to]);
    }
    debugger(evalInfo) {
        this.push([Ops.Debugger, evalInfo]);
        this.template.block.hasEval = true;
    }
    hasBlock(name) {
        this.pushValue([Ops.HasBlock, name]);
    }
    hasBlockParams(name) {
        this.pushValue([Ops.HasBlockParams, name]);
    }
    partial(evalInfo) {
        let params = this.popValue();
        this.push([Ops.Partial, params[0], evalInfo]);
        this.template.block.hasEval = true;
    }
    /// Expressions
    literal(value) {
        if (value === undefined) {
            this.pushValue([Ops.Undefined]);
        } else {
            this.pushValue(value);
        }
    }
    unknown(name) {
        this.pushValue([Ops.Unknown, name]);
    }
    get([head, path]) {
        this.pushValue([Ops.Get, head, path]);
    }
    maybeLocal(path) {
        this.pushValue([Ops.MaybeLocal, path]);
    }
    concat() {
        this.pushValue([Ops.Concat, this.popValue()]);
    }
    helper(name) {
        let params = this.popValue();
        let hash = this.popValue();
        this.pushValue([Ops.Helper, name, params, hash]);
    }
    /// Stack Management Opcodes
    prepareArray(size) {
        let values = [];
        for (let i = 0; i < size; i++) {
            values.push(this.popValue());
        }
        this.pushValue(values);
    }
    prepareObject(size) {

        let keys = new Array(size);
        let values = new Array(size);
        for (let i = 0; i < size; i++) {
            keys[i] = this.popValue();
            values[i] = this.popValue();
        }
        this.pushValue([keys, values]);
    }
    /// Utilities
    endComponent() {
        let component = this.blocks.pop();

        return component.toJSON();
    }
    push(args) {
        while (args[args.length - 1] === null) {
            args.pop();
        }
        this.currentBlock.push(args);
    }
    pushValue(val) {
        this.values.push(val);
    }
    popValue() {

        return this.values.pop();
    }
}

// There is a small whitelist of namespaced attributes specially
// enumerated in
// https://www.w3.org/TR/html/syntax.html#attributes-0
//
// > When a foreign element has one of the namespaced attributes given by
// > the local name and namespace of the first and second cells of a row
// > from the following table, it must be written using the name given by
// > the third cell from the same row.
//
// In all other cases, colons are interpreted as a regular character
// with no special meaning:
//
// > No other namespaced attribute can be expressed in the HTML syntax.
const XLINK = 'http://www.w3.org/1999/xlink';
const XML = 'http://www.w3.org/XML/1998/namespace';
const XMLNS = 'http://www.w3.org/2000/xmlns/';
const WHITELIST = {
    'xlink:actuate': XLINK,
    'xlink:arcrole': XLINK,
    'xlink:href': XLINK,
    'xlink:role': XLINK,
    'xlink:show': XLINK,
    'xlink:title': XLINK,
    'xlink:type': XLINK,
    'xml:base': XML,
    'xml:lang': XML,
    'xml:space': XML,
    xmlns: XMLNS,
    'xmlns:xlink': XMLNS
};
function getAttrNamespace(attrName) {
    return WHITELIST[attrName] || null;
}

class SymbolAllocator {
    constructor(ops) {
        this.ops = ops;
        this.symbolStack = new Stack();
    }
    process() {
        let out = [];
        let { ops } = this;
        for (let i = 0; i < ops.length; i++) {
            let op = ops[i];
            let result = this.dispatch(op);
            if (result === undefined) {
                out.push(op);
            } else {
                out.push(result);
            }
        }
        return out;
    }
    dispatch(op) {
        let name = op[0];
        let operand = op[1];
        return this[name](operand);
    }
    get symbols() {
        return this.symbolStack.current;
    }
    startProgram(op) {
        this.symbolStack.push(op['symbols']);
    }
    endProgram(_op) {
        this.symbolStack.pop();
    }
    startBlock(op) {
        this.symbolStack.push(op['symbols']);
    }
    endBlock(_op) {
        this.symbolStack.pop();
    }
    flushElement(op) {
        this.symbolStack.push(op['symbols']);
    }
    closeElement(_op) {
        this.symbolStack.pop();
    }
    closeComponent(_op) {
        this.symbolStack.pop();
    }
    closeDynamicComponent(_op) {
        this.symbolStack.pop();
    }
    attrSplat(_op) {
        return ['attrSplat', this.symbols.allocateBlock('attrs')];
    }
    get(op) {
        let [name, rest] = op;
        if (name === 0) {
            return ['get', [0, rest]];
        }
        if (isLocal(name, this.symbols)) {
            let head = this.symbols.get(name);
            return ['get', [head, rest]];
        } else if (name[0] === '@') {
            let head = this.symbols.allocateNamed(name);
            return ['get', [head, rest]];
        } else {
            return ['maybeLocal', [name, ...rest]];
        }
    }
    maybeGet(op) {
        let [name, rest] = op;
        if (name === 0) {
            return ['get', [0, rest]];
        }
        if (isLocal(name, this.symbols)) {
            let head = this.symbols.get(name);
            return ['get', [head, rest]];
        } else if (name[0] === '@') {
            let head = this.symbols.allocateNamed(name);
            return ['get', [head, rest]];
        } else if (rest.length === 0) {
            return ['unknown', name];
        } else {
            return ['maybeLocal', [name, ...rest]];
        }
    }
    yield(op) {
        if (op === 0) {
            throw new Error('Cannot yield to this');
        }
        return ['yield', this.symbols.allocateBlock(op)];
    }
    debugger(_op) {
        return ['debugger', this.symbols.getEvalInfo()];
    }
    hasBlock(op) {
        if (op === 0) {
            throw new Error('Cannot hasBlock this');
        }
        return ['hasBlock', this.symbols.allocateBlock(op)];
    }
    hasBlockParams(op) {
        if (op === 0) {
            throw new Error('Cannot hasBlockParams this');
        }
        return ['hasBlockParams', this.symbols.allocateBlock(op)];
    }
    partial(_op) {
        return ['partial', this.symbols.getEvalInfo()];
    }
    text(_op) {}
    comment(_op) {}
    openComponent(_op) {}
    openElement(_op) {}
    openSplattedElement(_op) {}
    staticArg(_op) {}
    dynamicArg(_op) {}
    staticAttr(_op) {}
    trustingAttr(_op) {}
    dynamicAttr(_op) {}
    modifier(_op) {}
    append(_op) {}
    block(_op) {}
    literal(_op) {}
    helper(_op) {}
    unknown(_op) {}
    maybeLocal(_op) {}
    prepareArray(_op) {}
    prepareObject(_op) {}
    concat(_op) {}
}
function isLocal(name, symbols) {
    return symbols && symbols.has(name);
}

function isTrustedValue(value) {
    return value.escaped !== undefined && !value.escaped;
}
class TemplateCompiler {
    constructor() {
        this.templateId = 0;
        this.templateIds = [];
        this.opcodes = [];
        this.includeMeta = false;
    }
    static compile(ast, options) {
        let templateVisitor = new TemplateVisitor();
        templateVisitor.visit(ast);
        let compiler = new TemplateCompiler();
        let opcodes = compiler.process(templateVisitor.actions);
        let symbols = new SymbolAllocator(opcodes).process();
        return JavaScriptCompiler.process(symbols, ast['symbols'], options);
    }
    process(actions) {
        actions.forEach(([name, ...args]) => {
            if (!this[name]) {
                throw new Error(`Unimplemented ${name} on TemplateCompiler`);
            }
            this[name](...args);
        });
        return this.opcodes;
    }
    startProgram([program]) {
        this.opcode(['startProgram', program], program);
    }
    endProgram() {
        this.opcode(['endProgram', null], null);
    }
    startBlock([program]) {
        this.templateId++;
        this.opcode(['startBlock', program], program);
    }
    endBlock() {
        this.templateIds.push(this.templateId - 1);
        this.opcode(['endBlock', null], null);
    }
    text([action]) {
        this.opcode(['text', action.chars], action);
    }
    comment([action]) {
        this.opcode(['comment', action.value], action);
    }
    openElement([action]) {
        let attributes = action.attributes;
        let hasSplat;
        for (let i = 0; i < attributes.length; i++) {
            let attr = attributes[i];
            if (attr.name === '...attributes') {
                hasSplat = attr;
                break;
            }
        }
        if (isDynamicComponent(action)) {
            let head, rest;
            [head, ...rest] = action.tag.split('.');
            if (head === 'this') {
                head = 0;
            }
            this.opcode(['get', [head, rest]]);
            this.opcode(['openComponent', action], action);
        } else if (isComponent(action)) {
            this.opcode(['openComponent', action], action);
        } else if (hasSplat) {
            this.opcode(['openSplattedElement', action], action);
        } else {
            this.opcode(['openElement', action], action);
        }
        let typeAttr = null;
        let attrs = action.attributes;
        for (let i = 0; i < attrs.length; i++) {
            if (attrs[i].name === 'type') {
                typeAttr = attrs[i];
                continue;
            }
            this.attribute([attrs[i]]);
        }
        if (typeAttr) {
            this.attribute([typeAttr]);
        }
        this.opcode(['flushElement', action], null);
    }
    closeElement([action]) {
        if (isDynamicComponent(action)) {
            this.opcode(['closeDynamicComponent', action], action);
        } else if (isComponent(action)) {
            this.opcode(['closeComponent', action], action);
        } else if (action.modifiers.length > 0) {
            for (let i = 0; i < action.modifiers.length; i++) {
                this.modifier([action.modifiers[i]]);
            }
            this.opcode(['closeElement', action], action);
        } else {
            this.opcode(['closeElement', action], action);
        }
    }
    attribute([action]) {
        let { name, value } = action;
        let namespace = getAttrNamespace(name);
        let isStatic = this.prepareAttributeValue(value);
        if (name.charAt(0) === '@') {
            // Arguments
            if (isStatic) {
                this.opcode(['staticArg', name], action);
            } else if (action.value.type === 'MustacheStatement') {
                this.opcode(['dynamicArg', name], action);
            } else {
                this.opcode(['dynamicArg', name], action);
            }
        } else {
            let isTrusting = isTrustedValue(value);
            if (isStatic && name === '...attributes') {
                this.opcode(['attrSplat', null], action);
            } else if (isStatic) {
                this.opcode(['staticAttr', [name, namespace]], action);
            } else if (isTrusting) {
                this.opcode(['trustingAttr', [name, namespace]], action);
            } else if (action.value.type === 'MustacheStatement') {
                this.opcode(['dynamicAttr', [name, null]], action);
            } else {
                this.opcode(['dynamicAttr', [name, namespace]], action);
            }
        }
    }
    modifier([action]) {
        assertIsSimplePath(action.path, action.loc, 'modifier');
        let { path: { parts } } = action;
        this.prepareHelper(action);
        this.opcode(['modifier', parts[0]], action);
    }
    mustache([action]) {
        let { path } = action;
        if (isLiteral(path)) {
            this.mustacheExpression(action);
            this.opcode(['append', !action.escaped], action);
        } else if (isYield(path)) {
            let to = assertValidYield(action);
            this.yield(to, action);
        } else if (isPartial(path)) {
            let params = assertValidPartial(action);
            this.partial(params, action);
        } else if (isDebugger(path)) {
            assertValidDebuggerUsage(action);
            this.debugger('debugger', action);
        } else {
            this.mustacheExpression(action);
            this.opcode(['append', !action.escaped], action);
        }
    }
    block([action /*, index, count*/]) {
        this.prepareHelper(action);
        let templateId = this.templateIds.pop();
        let inverseId = action.inverse === null ? null : this.templateIds.pop();
        this.opcode(['block', [action.path.parts[0], templateId, inverseId]], action);
    }
    /// Internal actions, not found in the original processed actions
    arg([path]) {
        let { parts: [head, ...rest] } = path;
        this.opcode(['get', [`@${head}`, rest]], path);
    }
    mustacheExpression(expr) {
        let { path } = expr;
        if (isLiteral(path)) {
            this.opcode(['literal', path.value], expr);
        } else if (isBuiltInHelper(path)) {
            this.builtInHelper(expr);
        } else if (isArg(path)) {
            this.arg([path]);
        } else if (isHelperInvocation(expr)) {
            this.prepareHelper(expr);
            this.opcode(['helper', path.parts[0]], expr);
        } else if (path.this) {
            this.opcode(['get', [0, path.parts]], expr);
        } else {
            let [head, ...parts] = path.parts;
            this.opcode(['maybeGet', [head, parts]], expr);
        }
        // } else if (isLocal(path, this.symbols)) {
        //   let [head, ...parts] = path.parts;
        //   this.opcode(['get', [head, parts]], expr);
        // } else if (isSimplePath(path)) {
        //   this.opcode(['unknown', path.parts[0]], expr);
        // } else {
        //   this.opcode(['maybeLocal', path.parts], expr);
        // }
    }
    /// Internal Syntax
    yield(to, action) {
        this.prepareParams(action.params);
        this.opcode(['yield', to], action);
    }
    debugger(_name, action) {
        this.opcode(['debugger', null], action);
    }
    hasBlock(name, action) {
        this.opcode(['hasBlock', name], action);
    }
    hasBlockParams(name, action) {
        this.opcode(['hasBlockParams', name], action);
    }
    partial(_params, action) {
        this.prepareParams(action.params);
        this.opcode(['partial', null], action);
    }
    builtInHelper(expr) {
        let { path } = expr;
        if (isHasBlock(path)) {
            let name = assertValidHasBlockUsage(expr.path.original, expr);
            this.hasBlock(name, expr);
        } else if (isHasBlockParams(path)) {
            let name = assertValidHasBlockUsage(expr.path.original, expr);
            this.hasBlockParams(name, expr);
        }
    }
    /// Expressions, invoked recursively from prepareParams and prepareHash
    SubExpression(expr) {
        if (isBuiltInHelper(expr.path)) {
            this.builtInHelper(expr);
        } else {
            this.prepareHelper(expr);
            this.opcode(['helper', expr.path.parts[0]], expr);
        }
    }
    PathExpression(expr) {
        if (expr.data) {
            this.arg([expr]);
        } else {
            let [head, ...rest] = expr.parts;
            if (expr.this) {
                this.opcode(['get', [0, expr.parts]], expr);
            } else {
                this.opcode(['get', [head, rest]], expr);
            }
        }
    }
    StringLiteral(action) {
        this.opcode(['literal', action.value], action);
    }
    BooleanLiteral(action) {
        this.opcode(['literal', action.value], action);
    }
    NumberLiteral(action) {
        this.opcode(['literal', action.value], action);
    }
    NullLiteral(action) {
        this.opcode(['literal', action.value], action);
    }
    UndefinedLiteral(action) {
        this.opcode(['literal', action.value], action);
    }
    /// Utilities
    opcode(opcode, action = null) {
        // TODO: This doesn't really work
        if (this.includeMeta && action) {
            opcode.push(this.meta(action));
        }
        this.opcodes.push(opcode);
    }
    prepareHelper(expr) {
        assertIsSimplePath(expr.path, expr.loc, 'helper');
        let { params, hash } = expr;
        this.prepareHash(hash);
        this.prepareParams(params);
    }
    prepareParams(params) {
        if (!params.length) {
            this.opcode(['literal', null], null);
            return;
        }
        for (let i = params.length - 1; i >= 0; i--) {
            let param = params[i];

            this[param.type](param);
        }
        this.opcode(['prepareArray', params.length], null);
    }
    prepareHash(hash) {
        let pairs = hash.pairs;
        if (!pairs.length) {
            this.opcode(['literal', null], null);
            return;
        }
        for (let i = pairs.length - 1; i >= 0; i--) {
            let { key, value } = pairs[i];

            this[value.type](value);
            this.opcode(['literal', key], null);
        }
        this.opcode(['prepareObject', pairs.length], null);
    }
    prepareAttributeValue(value) {
        // returns the static value if the value is static
        switch (value.type) {
            case 'TextNode':
                this.opcode(['literal', value.chars], value);
                return true;
            case 'MustacheStatement':
                this.attributeMustache([value]);
                return false;
            case 'ConcatStatement':
                this.prepareConcatParts(value.parts);
                this.opcode(['concat', null], value);
                return false;
        }
    }
    prepareConcatParts(parts) {
        for (let i = parts.length - 1; i >= 0; i--) {
            let part = parts[i];
            if (part.type === 'MustacheStatement') {
                this.attributeMustache([part]);
            } else if (part.type === 'TextNode') {
                this.opcode(['literal', part.chars], null);
            }
        }
        this.opcode(['prepareArray', parts.length], null);
    }
    attributeMustache([action]) {
        this.mustacheExpression(action);
    }
    meta(node) {
        let loc = node.loc;
        if (!loc) {
            return [];
        }
        let { source, start, end } = loc;
        return ['loc', [source || null, [start.line, start.column], [end.line, end.column]]];
    }
}
function isHelperInvocation(mustache) {
    return mustache.params && mustache.params.length > 0 || mustache.hash && mustache.hash.pairs.length > 0;
}
function isSimplePath({ parts }) {
    return parts.length === 1;
}
function isYield(path) {
    return path.original === 'yield';
}
function isPartial(path) {
    return path.original === 'partial';
}
function isDebugger(path) {
    return path.original === 'debugger';
}
function isHasBlock(path) {
    return path.original === 'has-block';
}
function isHasBlockParams(path) {
    return path.original === 'has-block-params';
}
function isBuiltInHelper(path) {
    return isHasBlock(path) || isHasBlockParams(path);
}
function isArg(path) {
    return !!path['data'];
}
function isDynamicComponent(element) {
    let open = element.tag.charAt(0);
    let [maybeLocal] = element.tag.split('.');
    let isNamedArgument = open === '@';
    let isLocal = element['symbols'].has(maybeLocal);
    let isThisPath = element.tag.indexOf('this.') === 0;
    return isLocal || isNamedArgument || isThisPath;
}
function isComponent(element) {
    let open = element.tag.charAt(0);
    let isPath = element.tag.indexOf('.') > -1;
    let isUpperCase = open === open.toUpperCase() && open !== open.toLowerCase();
    return isUpperCase && !isPath || isDynamicComponent(element);
}
function assertIsSimplePath(path, loc, context) {
    if (!isSimplePath(path)) {
        throw new SyntaxError(`\`${path.original}\` is not a valid name for a ${context} on line ${loc.start.line}.`, path.loc);
    }
}
function assertValidYield(statement) {
    let { pairs } = statement.hash;
    if (pairs.length === 1 && pairs[0].key !== 'to' || pairs.length > 1) {
        throw new SyntaxError(`yield only takes a single named argument: 'to'`, statement.loc);
    } else if (pairs.length === 1 && pairs[0].value.type !== 'StringLiteral') {
        throw new SyntaxError(`you can only yield to a literal value`, statement.loc);
    } else if (pairs.length === 0) {
        return 'default';
    } else {
        return pairs[0].value.value;
    }
}
function assertValidPartial(statement) {
    let { params, hash, escaped, loc } = statement;
    if (params && params.length !== 1) {
        throw new SyntaxError(`Partial found with no arguments. You must specify a template name. (on line ${loc.start.line})`, statement.loc);
    } else if (hash && hash.pairs.length > 0) {
        throw new SyntaxError(`partial does not take any named arguments (on line ${loc.start.line})`, statement.loc);
    } else if (!escaped) {
        throw new SyntaxError(`{{{partial ...}}} is not supported, please use {{partial ...}} instead (on line ${loc.start.line})`, statement.loc);
    }
    return params;
}
function assertValidHasBlockUsage(type, call) {
    let { params, hash, loc } = call;
    if (hash && hash.pairs.length > 0) {
        throw new SyntaxError(`${type} does not take any named arguments`, call.loc);
    }
    if (params.length === 0) {
        return 'default';
    } else if (params.length === 1) {
        let param = params[0];
        if (param.type === 'StringLiteral') {
            return param.value;
        } else {
            throw new SyntaxError(`you can only yield to a literal value (on line ${loc.start.line})`, call.loc);
        }
    } else {
        throw new SyntaxError(`${type} only takes a single positional argument (on line ${loc.start.line})`, call.loc);
    }
}
function assertValidDebuggerUsage(statement) {
    let { params, hash } = statement;
    if (hash && hash.pairs.length > 0) {
        throw new SyntaxError(`debugger does not take any named arguments`, statement.loc);
    }
    if (params.length === 0) {
        return 'default';
    } else {
        throw new SyntaxError(`debugger does not take any positional arguments`, statement.loc);
    }
}

const defaultId = (() => {
    if (typeof require === 'function') {
        try {
            /* tslint:disable:no-require-imports */
            const crypto = require('crypto');
            /* tslint:enable:no-require-imports */
            let idFn = src => {
                let hash = crypto.createHash('sha1');
                hash.update(src, 'utf8');
                // trim to 6 bytes of data (2^48 - 1)
                return hash.digest('base64').substring(0, 8);
            };
            idFn('test');
            return idFn;
        } catch (e) {}
    }
    return function idFn() {
        return null;
    };
})();
const defaultOptions = {
    id: defaultId,
    meta: {}
};
function precompile(string, options = defaultOptions) {
    let ast = preprocess(string, options);
    let { meta } = options;
    let { block } = TemplateCompiler.compile(ast, options);
    let idFn = options.id || defaultId;
    let blockJSON = JSON.stringify(block.toJSON());
    let templateJSONObject = {
        id: idFn(JSON.stringify(meta) + blockJSON),
        block: blockJSON,
        meta: meta
    };
    // JSON is javascript
    return JSON.stringify(templateJSONObject);
}

export { defaultId, precompile, TemplateCompiler, TemplateVisitor };