/*---------------------------------------------------------------------------------------------
 *  Copyright (c) Microsoft Corporation. All rights reserved.
 *  Licensed under the MIT License. See License.txt in the project root for license information.
 *--------------------------------------------------------------------------------------------*/
import { groupBy } from '../../../base/common/arrays.js';
import { dispose } from '../../../base/common/lifecycle.js';
import { getLeadingWhitespace } from '../../../base/common/strings.js';
import './snippetSession.css';
import { EditOperation } from '../../common/core/editOperation.js';
import { Range } from '../../common/core/range.js';
import { Selection } from '../../common/core/selection.js';
import { ModelDecorationOptions } from '../../common/model/textModel.js';
import { ILabelService } from '../../../platform/label/common/label.js';
import { IWorkspaceContextService } from '../../../platform/workspace/common/workspace.js';
import { Choice, Placeholder, SnippetParser, Text } from './snippetParser.js';
import { ClipboardBasedVariableResolver, CommentBasedVariableResolver, CompositeSnippetVariableResolver, ModelBasedVariableResolver, RandomBasedVariableResolver, SelectionBasedVariableResolver, TimeBasedVariableResolver, WorkspaceBasedVariableResolver } from './snippetVariables.js';
export class OneSnippet {
    constructor(_editor, _snippet, _offset, _snippetLineLeadingWhitespace) {
        this._editor = _editor;
        this._snippet = _snippet;
        this._offset = _offset;
        this._snippetLineLeadingWhitespace = _snippetLineLeadingWhitespace;
        this._nestingLevel = 1;
        this._placeholderGroups = groupBy(_snippet.placeholders, Placeholder.compareByIndex);
        this._placeholderGroupsIdx = -1;
    }
    dispose() {
        if (this._placeholderDecorations) {
            this._editor.deltaDecorations([...this._placeholderDecorations.values()], []);
        }
        this._placeholderGroups.length = 0;
    }
    _initDecorations() {
        if (this._placeholderDecorations) {
            // already initialized
            return;
        }
        this._placeholderDecorations = new Map();
        const model = this._editor.getModel();
        this._editor.changeDecorations(accessor => {
            // create a decoration for each placeholder
            for (const placeholder of this._snippet.placeholders) {
                const placeholderOffset = this._snippet.offset(placeholder);
                const placeholderLen = this._snippet.fullLen(placeholder);
                const range = Range.fromPositions(model.getPositionAt(this._offset + placeholderOffset), model.getPositionAt(this._offset + placeholderOffset + placeholderLen));
                const options = placeholder.isFinalTabstop ? OneSnippet._decor.inactiveFinal : OneSnippet._decor.inactive;
                const handle = accessor.addDecoration(range, options);
                this._placeholderDecorations.set(placeholder, handle);
            }
        });
    }
    move(fwd) {
        if (!this._editor.hasModel()) {
            return [];
        }
        this._initDecorations();
        // Transform placeholder text if necessary
        if (this._placeholderGroupsIdx >= 0) {
            let operations = [];
            for (const placeholder of this._placeholderGroups[this._placeholderGroupsIdx]) {
                // Check if the placeholder has a transformation
                if (placeholder.transform) {
                    const id = this._placeholderDecorations.get(placeholder);
                    const range = this._editor.getModel().getDecorationRange(id);
                    const currentValue = this._editor.getModel().getValueInRange(range);
                    const transformedValueLines = placeholder.transform.resolve(currentValue).split(/\r\n|\r|\n/);
                    // fix indentation for transformed lines
                    for (let i = 1; i < transformedValueLines.length; i++) {
                        transformedValueLines[i] = this._editor.getModel().normalizeIndentation(this._snippetLineLeadingWhitespace + transformedValueLines[i]);
                    }
                    operations.push(EditOperation.replace(range, transformedValueLines.join(this._editor.getModel().getEOL())));
                }
            }
            if (operations.length > 0) {
                this._editor.executeEdits('snippet.placeholderTransform', operations);
            }
        }
        let couldSkipThisPlaceholder = false;
        if (fwd === true && this._placeholderGroupsIdx < this._placeholderGroups.length - 1) {
            this._placeholderGroupsIdx += 1;
            couldSkipThisPlaceholder = true;
        }
        else if (fwd === false && this._placeholderGroupsIdx > 0) {
            this._placeholderGroupsIdx -= 1;
            couldSkipThisPlaceholder = true;
        }
        else {
            // the selection of the current placeholder might
            // not acurate any more -> simply restore it
        }
        const newSelections = this._editor.getModel().changeDecorations(accessor => {
            const activePlaceholders = new Set();
            // change stickiness to always grow when typing at its edges
            // because these decorations represent the currently active
            // tabstop.
            // Special case #1: reaching the final tabstop
            // Special case #2: placeholders enclosing active placeholders
            const selections = [];
            for (const placeholder of this._placeholderGroups[this._placeholderGroupsIdx]) {
                const id = this._placeholderDecorations.get(placeholder);
                const range = this._editor.getModel().getDecorationRange(id);
                selections.push(new Selection(range.startLineNumber, range.startColumn, range.endLineNumber, range.endColumn));
                // consider to skip this placeholder index when the decoration
                // range is empty but when the placeholder wasn't. that's a strong
                // hint that the placeholder has been deleted. (all placeholder must match this)
                couldSkipThisPlaceholder = couldSkipThisPlaceholder && this._hasPlaceholderBeenCollapsed(placeholder);
                accessor.changeDecorationOptions(id, placeholder.isFinalTabstop ? OneSnippet._decor.activeFinal : OneSnippet._decor.active);
                activePlaceholders.add(placeholder);
                for (const enclosingPlaceholder of this._snippet.enclosingPlaceholders(placeholder)) {
                    const id = this._placeholderDecorations.get(enclosingPlaceholder);
                    accessor.changeDecorationOptions(id, enclosingPlaceholder.isFinalTabstop ? OneSnippet._decor.activeFinal : OneSnippet._decor.active);
                    activePlaceholders.add(enclosingPlaceholder);
                }
            }
            // change stickness to never grow when typing at its edges
            // so that in-active tabstops never grow
            for (const [placeholder, id] of this._placeholderDecorations) {
                if (!activePlaceholders.has(placeholder)) {
                    accessor.changeDecorationOptions(id, placeholder.isFinalTabstop ? OneSnippet._decor.inactiveFinal : OneSnippet._decor.inactive);
                }
            }
            return selections;
        });
        return !couldSkipThisPlaceholder ? newSelections !== null && newSelections !== void 0 ? newSelections : [] : this.move(fwd);
    }
    _hasPlaceholderBeenCollapsed(placeholder) {
        // A placeholder is empty when it wasn't empty when authored but
        // when its tracking decoration is empty. This also applies to all
        // potential parent placeholders
        let marker = placeholder;
        while (marker) {
            if (marker instanceof Placeholder) {
                const id = this._placeholderDecorations.get(marker);
                const range = this._editor.getModel().getDecorationRange(id);
                if (range.isEmpty() && marker.toString().length > 0) {
                    return true;
                }
            }
            marker = marker.parent;
        }
        return false;
    }
    get isAtFirstPlaceholder() {
        return this._placeholderGroupsIdx <= 0 || this._placeholderGroups.length === 0;
    }
    get isAtLastPlaceholder() {
        return this._placeholderGroupsIdx === this._placeholderGroups.length - 1;
    }
    get hasPlaceholder() {
        return this._snippet.placeholders.length > 0;
    }
    computePossibleSelections() {
        const result = new Map();
        for (const placeholdersWithEqualIndex of this._placeholderGroups) {
            let ranges;
            for (const placeholder of placeholdersWithEqualIndex) {
                if (placeholder.isFinalTabstop) {
                    // ignore those
                    break;
                }
                if (!ranges) {
                    ranges = [];
                    result.set(placeholder.index, ranges);
                }
                const id = this._placeholderDecorations.get(placeholder);
                const range = this._editor.getModel().getDecorationRange(id);
                if (!range) {
                    // one of the placeholder lost its decoration and
                    // therefore we bail out and pretend the placeholder
                    // (with its mirrors) doesn't exist anymore.
                    result.delete(placeholder.index);
                    break;
                }
                ranges.push(range);
            }
        }
        return result;
    }
    get choice() {
        return this._placeholderGroups[this._placeholderGroupsIdx][0].choice;
    }
    merge(others) {
        const model = this._editor.getModel();
        this._nestingLevel *= 10;
        this._editor.changeDecorations(accessor => {
            // For each active placeholder take one snippet and merge it
            // in that the placeholder (can be many for `$1foo$1foo`). Because
            // everything is sorted by editor selection we can simply remove
            // elements from the beginning of the array
            for (const placeholder of this._placeholderGroups[this._placeholderGroupsIdx]) {
                const nested = others.shift();
                console.assert(!nested._placeholderDecorations);
                // Massage placeholder-indicies of the nested snippet to be
                // sorted right after the insertion point. This ensures we move
                // through the placeholders in the correct order
                const indexLastPlaceholder = nested._snippet.placeholderInfo.last.index;
                for (const nestedPlaceholder of nested._snippet.placeholderInfo.all) {
                    if (nestedPlaceholder.isFinalTabstop) {
                        nestedPlaceholder.index = placeholder.index + ((indexLastPlaceholder + 1) / this._nestingLevel);
                    }
                    else {
                        nestedPlaceholder.index = placeholder.index + (nestedPlaceholder.index / this._nestingLevel);
                    }
                }
                this._snippet.replace(placeholder, nested._snippet.children);
                // Remove the placeholder at which position are inserting
                // the snippet and also remove its decoration.
                const id = this._placeholderDecorations.get(placeholder);
                accessor.removeDecoration(id);
                this._placeholderDecorations.delete(placeholder);
                // For each *new* placeholder we create decoration to monitor
                // how and if it grows/shrinks.
                for (const placeholder of nested._snippet.placeholders) {
                    const placeholderOffset = nested._snippet.offset(placeholder);
                    const placeholderLen = nested._snippet.fullLen(placeholder);
                    const range = Range.fromPositions(model.getPositionAt(nested._offset + placeholderOffset), model.getPositionAt(nested._offset + placeholderOffset + placeholderLen));
                    const handle = accessor.addDecoration(range, OneSnippet._decor.inactive);
                    this._placeholderDecorations.set(placeholder, handle);
                }
            }
            // Last, re-create the placeholder groups by sorting placeholders by their index.
            this._placeholderGroups = groupBy(this._snippet.placeholders, Placeholder.compareByIndex);
        });
    }
}
OneSnippet._decor = {
    active: ModelDecorationOptions.register({ description: 'snippet-placeholder-1', stickiness: 0 /* AlwaysGrowsWhenTypingAtEdges */, className: 'snippet-placeholder' }),
    inactive: ModelDecorationOptions.register({ description: 'snippet-placeholder-2', stickiness: 1 /* NeverGrowsWhenTypingAtEdges */, className: 'snippet-placeholder' }),
    activeFinal: ModelDecorationOptions.register({ description: 'snippet-placeholder-3', stickiness: 1 /* NeverGrowsWhenTypingAtEdges */, className: 'finish-snippet-placeholder' }),
    inactiveFinal: ModelDecorationOptions.register({ description: 'snippet-placeholder-4', stickiness: 1 /* NeverGrowsWhenTypingAtEdges */, className: 'finish-snippet-placeholder' }),
};
const _defaultOptions = {
    overwriteBefore: 0,
    overwriteAfter: 0,
    adjustWhitespace: true,
    clipboardText: undefined,
    overtypingCapturer: undefined
};
export class SnippetSession {
    constructor(editor, template, options = _defaultOptions) {
        this._templateMerges = [];
        this._snippets = [];
        this._editor = editor;
        this._template = template;
        this._options = options;
    }
    static adjustWhitespace(model, position, snippet, adjustIndentation, adjustNewlines) {
        const line = model.getLineContent(position.lineNumber);
        const lineLeadingWhitespace = getLeadingWhitespace(line, 0, position.column - 1);
        // the snippet as inserted
        let snippetTextString;
        snippet.walk(marker => {
            // all text elements that are not inside choice
            if (!(marker instanceof Text) || marker.parent instanceof Choice) {
                return true;
            }
            const lines = marker.value.split(/\r\n|\r|\n/);
            if (adjustIndentation) {
                // adjust indentation of snippet test
                // -the snippet-start doesn't get extra-indented (lineLeadingWhitespace), only normalized
                // -all N+1 lines get extra-indented and normalized
                // -the text start get extra-indented and normalized when following a linebreak
                const offset = snippet.offset(marker);
                if (offset === 0) {
                    // snippet start
                    lines[0] = model.normalizeIndentation(lines[0]);
                }
                else {
                    // check if text start is after a linebreak
                    snippetTextString = snippetTextString !== null && snippetTextString !== void 0 ? snippetTextString : snippet.toString();
                    let prevChar = snippetTextString.charCodeAt(offset - 1);
                    if (prevChar === 10 /* LineFeed */ || prevChar === 13 /* CarriageReturn */) {
                        lines[0] = model.normalizeIndentation(lineLeadingWhitespace + lines[0]);
                    }
                }
                for (let i = 1; i < lines.length; i++) {
                    lines[i] = model.normalizeIndentation(lineLeadingWhitespace + lines[i]);
                }
            }
            const newValue = lines.join(model.getEOL());
            if (newValue !== marker.value) {
                marker.parent.replace(marker, [new Text(newValue)]);
                snippetTextString = undefined;
            }
            return true;
        });
        return lineLeadingWhitespace;
    }
    static adjustSelection(model, selection, overwriteBefore, overwriteAfter) {
        if (overwriteBefore !== 0 || overwriteAfter !== 0) {
            // overwrite[Before|After] is compute using the position, not the whole
            // selection. therefore we adjust the selection around that position
            const { positionLineNumber, positionColumn } = selection;
            const positionColumnBefore = positionColumn - overwriteBefore;
            const positionColumnAfter = positionColumn + overwriteAfter;
            const range = model.validateRange({
                startLineNumber: positionLineNumber,
                startColumn: positionColumnBefore,
                endLineNumber: positionLineNumber,
                endColumn: positionColumnAfter
            });
            selection = Selection.createWithDirection(range.startLineNumber, range.startColumn, range.endLineNumber, range.endColumn, selection.getDirection());
        }
        return selection;
    }
    static createEditsAndSnippets(editor, template, overwriteBefore, overwriteAfter, enforceFinalTabstop, adjustWhitespace, clipboardText, overtypingCapturer) {
        const edits = [];
        const snippets = [];
        if (!editor.hasModel()) {
            return { edits, snippets };
        }
        const model = editor.getModel();
        const workspaceService = editor.invokeWithinContext(accessor => accessor.get(IWorkspaceContextService));
        const modelBasedVariableResolver = editor.invokeWithinContext(accessor => new ModelBasedVariableResolver(accessor.get(ILabelService), model));
        const readClipboardText = () => clipboardText;
        let delta = 0;
        // know what text the overwrite[Before|After] extensions
        // of the primary curser have selected because only when
        // secondary selections extend to the same text we can grow them
        let firstBeforeText = model.getValueInRange(SnippetSession.adjustSelection(model, editor.getSelection(), overwriteBefore, 0));
        let firstAfterText = model.getValueInRange(SnippetSession.adjustSelection(model, editor.getSelection(), 0, overwriteAfter));
        // remember the first non-whitespace column to decide if
        // `keepWhitespace` should be overruled for secondary selections
        let firstLineFirstNonWhitespace = model.getLineFirstNonWhitespaceColumn(editor.getSelection().positionLineNumber);
        // sort selections by their start position but remeber
        // the original index. that allows you to create correct
        // offset-based selection logic without changing the
        // primary selection
        const indexedSelections = editor.getSelections()
            .map((selection, idx) => ({ selection, idx }))
            .sort((a, b) => Range.compareRangesUsingStarts(a.selection, b.selection));
        for (const { selection, idx } of indexedSelections) {
            // extend selection with the `overwriteBefore` and `overwriteAfter` and then
            // compare if this matches the extensions of the primary selection
            let extensionBefore = SnippetSession.adjustSelection(model, selection, overwriteBefore, 0);
            let extensionAfter = SnippetSession.adjustSelection(model, selection, 0, overwriteAfter);
            if (firstBeforeText !== model.getValueInRange(extensionBefore)) {
                extensionBefore = selection;
            }
            if (firstAfterText !== model.getValueInRange(extensionAfter)) {
                extensionAfter = selection;
            }
            // merge the before and after selection into one
            const snippetSelection = selection
                .setStartPosition(extensionBefore.startLineNumber, extensionBefore.startColumn)
                .setEndPosition(extensionAfter.endLineNumber, extensionAfter.endColumn);
            const snippet = new SnippetParser().parse(template, true, enforceFinalTabstop);
            // adjust the template string to match the indentation and
            // whitespace rules of this insert location (can be different for each cursor)
            // happens when being asked for (default) or when this is a secondary
            // cursor and the leading whitespace is different
            const start = snippetSelection.getStartPosition();
            const snippetLineLeadingWhitespace = SnippetSession.adjustWhitespace(model, start, snippet, adjustWhitespace || (idx > 0 && firstLineFirstNonWhitespace !== model.getLineFirstNonWhitespaceColumn(selection.positionLineNumber)), true);
            snippet.resolveVariables(new CompositeSnippetVariableResolver([
                modelBasedVariableResolver,
                new ClipboardBasedVariableResolver(readClipboardText, idx, indexedSelections.length, editor.getOption(70 /* multiCursorPaste */) === 'spread'),
                new SelectionBasedVariableResolver(model, selection, idx, overtypingCapturer),
                new CommentBasedVariableResolver(model, selection),
                new TimeBasedVariableResolver,
                new WorkspaceBasedVariableResolver(workspaceService),
                new RandomBasedVariableResolver,
            ]));
            const offset = model.getOffsetAt(start) + delta;
            delta += snippet.toString().length - model.getValueLengthInRange(snippetSelection);
            // store snippets with the index of their originating selection.
            // that ensures the primiary cursor stays primary despite not being
            // the one with lowest start position
            edits[idx] = EditOperation.replace(snippetSelection, snippet.toString());
            edits[idx].identifier = { major: idx, minor: 0 }; // mark the edit so only our undo edits will be used to generate end cursors
            snippets[idx] = new OneSnippet(editor, snippet, offset, snippetLineLeadingWhitespace);
        }
        return { edits, snippets };
    }
    dispose() {
        dispose(this._snippets);
    }
    _logInfo() {
        return `template="${this._template}", merged_templates="${this._templateMerges.join(' -> ')}"`;
    }
    insert() {
        if (!this._editor.hasModel()) {
            return;
        }
        // make insert edit and start with first selections
        const { edits, snippets } = SnippetSession.createEditsAndSnippets(this._editor, this._template, this._options.overwriteBefore, this._options.overwriteAfter, false, this._options.adjustWhitespace, this._options.clipboardText, this._options.overtypingCapturer);
        this._snippets = snippets;
        this._editor.executeEdits('snippet', edits, undoEdits => {
            if (this._snippets[0].hasPlaceholder) {
                return this._move(true);
            }
            else {
                return undoEdits
                    .filter(edit => !!edit.identifier) // only use our undo edits
                    .map(edit => Selection.fromPositions(edit.range.getEndPosition()));
            }
        });
        this._editor.revealRange(this._editor.getSelections()[0]);
    }
    merge(template, options = _defaultOptions) {
        if (!this._editor.hasModel()) {
            return;
        }
        this._templateMerges.push([this._snippets[0]._nestingLevel, this._snippets[0]._placeholderGroupsIdx, template]);
        const { edits, snippets } = SnippetSession.createEditsAndSnippets(this._editor, template, options.overwriteBefore, options.overwriteAfter, true, options.adjustWhitespace, options.clipboardText, options.overtypingCapturer);
        this._editor.executeEdits('snippet', edits, undoEdits => {
            for (const snippet of this._snippets) {
                snippet.merge(snippets);
            }
            console.assert(snippets.length === 0);
            if (this._snippets[0].hasPlaceholder) {
                return this._move(undefined);
            }
            else {
                return (undoEdits
                    .filter(edit => !!edit.identifier) // only use our undo edits
                    .map(edit => Selection.fromPositions(edit.range.getEndPosition())));
            }
        });
    }
    next() {
        const newSelections = this._move(true);
        this._editor.setSelections(newSelections);
        this._editor.revealPositionInCenterIfOutsideViewport(newSelections[0].getPosition());
    }
    prev() {
        const newSelections = this._move(false);
        this._editor.setSelections(newSelections);
        this._editor.revealPositionInCenterIfOutsideViewport(newSelections[0].getPosition());
    }
    _move(fwd) {
        const selections = [];
        for (const snippet of this._snippets) {
            const oneSelection = snippet.move(fwd);
            selections.push(...oneSelection);
        }
        return selections;
    }
    get isAtFirstPlaceholder() {
        return this._snippets[0].isAtFirstPlaceholder;
    }
    get isAtLastPlaceholder() {
        return this._snippets[0].isAtLastPlaceholder;
    }
    get hasPlaceholder() {
        return this._snippets[0].hasPlaceholder;
    }
    get choice() {
        return this._snippets[0].choice;
    }
    isSelectionWithinPlaceholders() {
        if (!this.hasPlaceholder) {
            return false;
        }
        const selections = this._editor.getSelections();
        if (selections.length < this._snippets.length) {
            // this means we started snippet mode with N
            // selections and have M (N > M) selections.
            // So one snippet is without selection -> cancel
            return false;
        }
        let allPossibleSelections = new Map();
        for (const snippet of this._snippets) {
            const possibleSelections = snippet.computePossibleSelections();
            // for the first snippet find the placeholder (and its ranges)
            // that contain at least one selection. for all remaining snippets
            // the same placeholder (and their ranges) must be used.
            if (allPossibleSelections.size === 0) {
                for (const [index, ranges] of possibleSelections) {
                    ranges.sort(Range.compareRangesUsingStarts);
                    for (const selection of selections) {
                        if (ranges[0].containsRange(selection)) {
                            allPossibleSelections.set(index, []);
                            break;
                        }
                    }
                }
            }
            if (allPossibleSelections.size === 0) {
                // return false if we couldn't associate a selection to
                // this (the first) snippet
                return false;
            }
            // add selections from 'this' snippet so that we know all
            // selections for this placeholder
            allPossibleSelections.forEach((array, index) => {
                array.push(...possibleSelections.get(index));
            });
        }
        // sort selections (and later placeholder-ranges). then walk both
        // arrays and make sure the placeholder-ranges contain the corresponding
        // selection
        selections.sort(Range.compareRangesUsingStarts);
        for (let [index, ranges] of allPossibleSelections) {
            if (ranges.length !== selections.length) {
                allPossibleSelections.delete(index);
                continue;
            }
            ranges.sort(Range.compareRangesUsingStarts);
            for (let i = 0; i < ranges.length; i++) {
                if (!ranges[i].containsRange(selections[i])) {
                    allPossibleSelections.delete(index);
                    continue;
                }
            }
        }
        // from all possible selections we have deleted those
        // that don't match with the current selection. if we don't
        // have any left, we don't have a selection anymore
        return allPossibleSelections.size > 0;
    }
}
