/******************************************************************************
 * Copyright 2022 TypeFox GmbH
 * This program and the accompanying materials are made available under the
 * terms of the MIT License, which is available in the project root.
 ******************************************************************************/
import { NEWLINE_REGEXP } from '../utils/regexp-utils.js';
import { CompositeGeneratorNode, isGeneratorNode, traceToNode } from './generator-node.js';
import { findIndentation } from './template-string.js';
/**
 * A tag function that attaches the template's content to a {@link CompositeGeneratorNode}.
 *
 * This is done segment by segment, and static template portions as well as substitutions
 * are added individually to the returned {@link CompositeGeneratorNode}.
 * At that common leading indentation of all the template's static parts is trimmed,
 * whereas additional indentations of particular lines within that static parts as well as
 * any line breaks and indentation within the substitutions are kept.
 *
 * For the sake of good readability and good composability of results of this function like
 * in the following example, the subsequent rule is applied.
 *
 * ```ts
 *  expandToNode`
 *   This is the beginning of something
 *
 *   ${foo.bar ? expandToNode`
 *     bla bla bla ${foo.bar}
 *
 *   `: undefined
 *   }
 *   end of template
 *  `
 * ```
 *
 * Rule:
 * In case of a multiline template the content of the first line including its terminating
 * line break is ignored, if and only if it is empty of contains whitespace only. Futhermore,
 * in case of a multiline template the content of the last line including its preceding line break
 * (last one within the template) is ignored, if and only if it is empty of contains whitespace only.
 * Thus, the result of all of the following invocations is identical and equal to `generatedContent`.
 * ```ts
 *  expandToNode`generatedContent`
 *  expandToNode`generatedContent
 *  `
 *  expandToNode`
 *    generatedContent`
 *  expandToNode`
 *    generatedContent
 *  `
 * ```
 *
 * In addition, a second rule is applied in the handling of line breaks:
 * If a line's last substitution contributes `undefined` or an object of type {@link GeneratorNode},
 * the subsequent line break will be appended via {@link CompositeGeneratorNode.appendNewLineIfNotEmpty}.
 * Hence, if all other segments of that line contribute whitespace characters only,
 * the entire line will be omitted while rendering the desired output.
 * Otherwise, linebreaks will be added via {@link CompositeGeneratorNode.appendNewLine}.
 * That holds in particular, if the last substitution contributes an empty string. In consequence,
 * adding `${''}` to the end of a line consisting of whitespace and substitions only
 * enforces the line break to be rendered, no matter what the substitions actually contribute.
 *
 * @param staticParts the static parts of a tagged template literal
 * @param substitutions the variable parts of a tagged template literal
 * @returns a 'CompositeGeneratorNode' containing the particular aligned lines
 *             after resolving and inserting the substitutions into the given parts
 */
export function expandToNode(staticParts, ...substitutions) {
    // first part: determine the common indentation of all the template lines with the substitutions being ignored
    const templateProps = findIndentationAndTemplateStructure(staticParts);
    // 2nd part: for all the static template parts: split them and inject a NEW_LINE marker where line breaks shall be a present in the final result,
    //  and create a flatten list of strings, NEW_LINE marker occurrences, and substitutions
    const splitAndMerged = splitTemplateLinesAndMergeWithSubstitutions(staticParts, substitutions, templateProps);
    // eventually, inject indentation nodes and append the segments to final desired composite generator node
    return composeFinalGeneratorNode(splitAndMerged);
}
// implementation:
export function expandTracedToNode(source, property, index) {
    return (staticParts, ...substitutions) => {
        return traceToNode(source, property, index)(expandToNode(staticParts, ...substitutions));
    };
}
// implementation:
export function expandTracedToNodeIf(condition, source, property, index) {
    return condition ? expandTracedToNode((typeof source === 'function' ? source() : source), property, index) : () => undefined;
}
function findIndentationAndTemplateStructure(staticParts) {
    const lines = staticParts.join('_').split(NEWLINE_REGEXP);
    const omitFirstLine = lines.length > 1 && lines[0].trim().length === 0;
    const omitLastLine = omitFirstLine && lines.length > 1 && lines[lines.length - 1].trim().length === 0;
    if (lines.length === 1 || lines.length !== 0 && lines[0].trim().length !== 0 || lines.length === 2 && lines[1].trim().length === 0) {
        // for cases of non-adjusted templates like
        //   const n1 = expandToNode` `;
        //   const n2 = expandToNode` something `;
        //   const n3 = expandToNode` something
        //   `;
        // ... consider the indentation to be empty, and all the leading whitespace to be relevant, except for the last (empty) line of n3!
        return {
            indentation: 0, //''
            omitFirstLine,
            omitLastLine,
            trimLastLine: lines.length !== 1 && lines[lines.length - 1].trim().length === 0
        };
    }
    else {
        // otherwise:
        // for cases of non-adjusted templates like
        //   const n4 = expandToNode` abc
        //     def `;
        //   const n5 = expandToNode`<maybe with some WS here>
        //      abc
        //     def`;
        //   const n6 = expandToNode`<maybe with some WS here>
        //      abc
        //     def
        //   `;
        // ... the indentation shall be determined by the non-empty lines, excluding the last line if it contains whitespace only
        // if we have a multi-line template and the first line is empty, see n5, n6
        //  ignore the first line;
        let sliced = omitFirstLine ? lines.slice(1) : lines;
        // if there're more than one line remaining and the last one only contains WS, see n6,
        //  ignore the last line
        sliced = omitLastLine ? sliced.slice(0, sliced.length - 1) : sliced;
        // ignore empty lines during indentation calculation, as linting rules might forbid lines containing just whitespace
        sliced = sliced.filter(e => e.length !== 0);
        const indentation = findIndentation(sliced);
        return {
            indentation,
            omitFirstLine,
            // in the subsequent steps omit the last line only if it is empty or if it only contains whitespace of which the common indentation is not a valid prefix;
            //  in other words: keep the last line if it matches the common indentation (and maybe contains non-whitespace), a non-match may be due to mistaken usage of tabs and spaces
            omitLastLine: omitLastLine && (lines[lines.length - 1].length < indentation || !lines[lines.length - 1].startsWith(sliced[0].substring(0, indentation)))
        };
    }
}
function splitTemplateLinesAndMergeWithSubstitutions(staticParts, substitutions, { indentation, omitFirstLine, omitLastLine, trimLastLine }) {
    const splitAndMerged = [];
    staticParts.forEach((part, i) => {
        splitAndMerged.push(...part.split(NEWLINE_REGEXP).map((e, j) => j === 0 || e.length < indentation ? e : e.substring(indentation)).reduce(
        // treat the particular (potentially multiple) lines of the <i>th template segment (part),
        //  s.t. all the effective lines are collected and separated by the NEWLINE node
        // note: different reduce functions are provided for the initial template segment vs. the remaining segments
        i === 0
            ? (result, line, j) => 
            // special handling of the initial template segment, which may contain line-breaks;
            //  suppresses the injection of unintended NEWLINE indicators for templates like
            //   expandToNode`
            //    someText
            //    ${something}
            //   `
            j === 0
                ? (omitFirstLine // for templates with empty first lines like above (expandToNode`\n ...`)
                    ? [] // skip adding the initial line
                    : [line] //  take the initial line if non-empty
                )
                : (j === 1 && result.length === 0 // when looking on the 2nd line in case the first line (in the first segment) is skipped ('result' is still empty)
                    ? [line] // skip the insertion of the NEWLINE marker and just return the current line
                    : result.concat(NEWLINE, line) // otherwise append the NEWLINE marker and the current line
                )
            : (result, line, j) => 
            // handling of the remaining template segments
            j === 0 ? [line] : result.concat(NEWLINE, line) // except for the first line in the current segment prepend each line with NEWLINE
        , [] // start with an empty array
        ).filter(e => !(typeof e === 'string' && e.length === 0) // drop empty strings, they don't contribute anything but might confuse subsequent processing
        ).concat(
        // append the corresponding substitution after each segment (part),
        //  note that 'substitutions[i]' will be undefined for the last segment
        isGeneratorNode(substitutions[i])
            // if the substitution is a generator node, take it as it is
            ? substitutions[i]
            : substitutions[i] !== undefined
                // if the substitution is something else, convert it to a string and wrap it;
                //  allows us below to distinguish template strings from substitution (esp. empty) ones
                ? { content: String(substitutions[i]) }
                : i < substitutions.length
                    // if 'substitutions[i]' is undefined and we are treating a substitution "in the middle"
                    //   we found a substitution that is assumed to not contribute anything on purpose!
                    ? UNDEFINED_SEGMENT // add a corresponding marker, see below for details on the rational
                    : [] /* don't concat anything as we passed behind the last substitution, since 'i' enumerates the indices of 'staticParts',
                                 but 'substitutions' has one entry less and 'substitutions[staticParts.length -1 ]' will always be undefined */));
    });
    // for templates like
    //   expandToNode`
    //    someText
    //   `
    // TODO add more documentation here
    const splitAndMergedLength = splitAndMerged.length;
    const lastItem = splitAndMergedLength !== 0 ? splitAndMerged[splitAndMergedLength - 1] : undefined;
    if ((omitLastLine || trimLastLine) && typeof lastItem === 'string' && lastItem.trim().length === 0) {
        if (omitFirstLine && splitAndMergedLength !== 1 && splitAndMerged[splitAndMergedLength - 2] === NEWLINE) {
            return splitAndMerged.slice(0, splitAndMergedLength - 2);
        }
        else {
            return splitAndMerged.slice(0, splitAndMergedLength - 1);
        }
    }
    else {
        return splitAndMerged;
    }
}
const NEWLINE = { isNewLine: true };
const UNDEFINED_SEGMENT = { isUndefinedSegment: true };
const isNewLineMarker = (nl) => nl === NEWLINE;
const isUndefinedSegmentMarker = (us) => us === UNDEFINED_SEGMENT;
const isSubstitutionWrapper = (s) => s.content !== undefined;
function composeFinalGeneratorNode(splitAndMerged) {
    // in order to properly handle the indentation of nested multi-line substitutions,
    //  track the length of static (string) parts per line and wrap the substitution(s) in indentation nodes, if needed
    //
    // of course, this only works nicely if a multi-line substitution is preceded by static string parts on the same line only;
    // in case of dynamic content (with a potentially unknown length) followed by a multi-line substitution
    //  the latter's indentation cannot be determined properly...
    const result = splitAndMerged.reduce((res, segment, i) => isUndefinedSegmentMarker(segment)
        // ignore all occurrences of UNDEFINED_SEGMENT, they are just in there for the below test
        //  of 'isNewLineMarker(splitAndMerged[i-1])' not to evaluate to 'truthy' in case of consecutive lines
        //  with no actual content in templates like
        //   expandToNode`
        //     Foo
        //     ${undefined} <<----- here
        //     ${undefined} <<----- and here
        //
        //     Bar
        //   `
        ? res
        : isNewLineMarker(segment)
            ? {
                // in case of a newLine marker append an 'ifNotEmpty' newLine by default, but
                //  append an unconditional newLine if and only if:
                //   * the template starts with the current line break, i.e. the first line is empty
                //   * the current newLine marker directly follows another one, i.e. the current line is empty
                //   * the current newline marker directly follows a substitution contributing a string (or some non-GeneratorNode being converted to a string)
                //   * the current newline marker directly follows a (template static) string that
                //      * is the initial token of the template
                //      * is the initial token of the line, maybe just indentation
                //      * follows a a substitution contributing a string (or some non-GeneratorNode being converted to a string), maybe is just irrelevant trailing whitespace
                // in particular do _not_ append an unconditional newLine if the last substitution of a line contributes 'undefined' or an instance of 'GeneratorNode'
                //  which may be a newline itself or be empty or (transitively) contain a trailing newline itself
                // node: i === 0
                //     || isNewLineMarker(splitAndMerged[i - 1]) || isSubstitutionWrapper(splitAndMerged[i - 1]) /* implies: typeof content === 'string', esp. !undefined */
                //     || typeof splitAndMerged[i - 1] === 'string' && (
                //         i === 1 || isNewLineMarker(splitAndMerged[i - 2]) || isSubstitutionWrapper(splitAndMerged[i - 2]) /* implies: typeof content === 'string', esp. !undefined */
                //     )
                //     ? res.node.appendNewLine() : res.node.appendNewLineIfNotEmpty()
                //
                // UPDATE cs: inverting the logic leads to the following, I hope I didn't miss anything:
                // in case of a newLine marker append an unconditional newLine by default, but
                //  append an 'ifNotEmpty' newLine if and only if:
                //   * the template doesn't start with a newLine marker and
                //      * the current newline marker directly follows a substitution contributing an `undefined` or an instance of 'GeneratorNode', or
                //      * the current newline marker directly follows a (template static) string (containing potentially unintended trailing whitespace)
                //          that in turn directly follows a substitution contributing an `undefined` or an instance of 'GeneratorNode'
                node: i !== 0 && (isUndefinedSegmentMarker(splitAndMerged[i - 1]) || isGeneratorNode(splitAndMerged[i - 1]))
                    || i > 1 && typeof splitAndMerged[i - 1] === 'string' && (isUndefinedSegmentMarker(splitAndMerged[i - 2]) || isGeneratorNode(splitAndMerged[i - 2]))
                    ? res.node.appendNewLineIfNotEmpty() : res.node.appendNewLine()
            } : (() => {
            var _a;
            // the indentation handling is supposed to handle use cases like
            //   bla bla bla {
            //      ${foo(bar)}
            //   }
            // and
            //   bla bla bla {
            //      return ${foo(bar)}
            //   }
            // assuming that ${foo(bar)} yields a multiline result;
            // the whitespace between 'return' and '${foo(bar)}' shall not add to the indentation of '${foo(bar)}'s result!
            const indent = (i === 0 || isNewLineMarker(splitAndMerged[i - 1])) && typeof segment === 'string' && segment.length !== 0 ? ''.padStart(segment.length - segment.trimStart().length) : '';
            const content = isSubstitutionWrapper(segment) ? segment.content : segment;
            let indented;
            return {
                node: res.indented
                    // in case an indentNode has been registered earlier for the current line,
                    //  just return 'node' without manipulation, the current segment will be added to the indentNode
                    ? res.node
                    // otherwise (no indentNode is registered by now)...
                    : indent.length !== 0
                        // in case an indentation has been identified add a non-immediate indentNode to 'node' and
                        //  add the current segment (containing its the indentation) to that indentNode,
                        //  and keep the indentNode in a local variable 'indented' for registering below,
                        //  and return 'node'
                        ? res.node.indent({ indentation: indent, indentImmediately: false, indentedChildren: ind => indented = ind.append(content) })
                        // otherwise just add the content to 'node' and return it
                        : res.node.append(content),
                indented: 
                // if an indentNode has been created in this cycle, just register it,
                //  otherwise check for a earlier registered indentNode and add the current segment to that one
                indented !== null && indented !== void 0 ? indented : (_a = res.indented) === null || _a === void 0 ? void 0 : _a.append(content),
            };
        })(), { node: new CompositeGeneratorNode() });
    return result.node;
}//# sourceMappingURL=https://main.vscode-cdn.net/sourcemaps/ecfbad74d93962fc8ca485d93ab9b4f3d4cb6cf8/node_modules/langium/lib/generate/template-node.js.map