import { EditorSelection, Prec, EditorState } from '@codemirror/state';
import { keymap } from '@codemirror/view';
import { syntaxTree, LanguageSupport, Language, defineLanguageFacet, foldNodeProp, indentNodeProp, languageDataProp, foldService, LanguageDescription, ParseContext } from '@codemirror/language';
import { CompletionContext } from '@codemirror/autocomplete';
import { MarkdownParser, parseCode, parser, GFM, Subscript, Superscript, Emoji } from '@lezer/markdown';
import { htmlCompletionSource, html } from '@codemirror/lang-html';
import { NodeProp } from '@lezer/common';

const data = /*@__PURE__*/defineLanguageFacet({ commentTokens: { block: { open: "<!--", close: "-->" } } });
const headingProp = /*@__PURE__*/new NodeProp();
const commonmark = /*@__PURE__*/parser.configure({
    props: [
        /*@__PURE__*/foldNodeProp.add(type => {
            return !type.is("Block") || type.is("Document") || isHeading(type) != null ? undefined
                : (tree, state) => ({ from: state.doc.lineAt(tree.from).to, to: tree.to });
        }),
        /*@__PURE__*/headingProp.add(isHeading),
        /*@__PURE__*/indentNodeProp.add({
            Document: () => null
        }),
        /*@__PURE__*/languageDataProp.add({
            Document: data
        })
    ]
});
function isHeading(type) {
    let match = /^(?:ATX|Setext)Heading(\d)$/.exec(type.name);
    return match ? +match[1] : undefined;
}
function findSectionEnd(headerNode, level) {
    let last = headerNode;
    for (;;) {
        let next = last.nextSibling, heading;
        if (!next || (heading = isHeading(next.type)) != null && heading <= level)
            break;
        last = next;
    }
    return last.to;
}
const headerIndent = /*@__PURE__*/foldService.of((state, start, end) => {
    for (let node = syntaxTree(state).resolveInner(end, -1); node; node = node.parent) {
        if (node.from < start)
            break;
        let heading = node.type.prop(headingProp);
        if (heading == null)
            continue;
        let upto = findSectionEnd(node, heading);
        if (upto > end)
            return { from: end, to: upto };
    }
    return null;
});
function mkLang(parser) {
    return new Language(data, parser, [headerIndent], "markdown");
}
/**
Language support for strict CommonMark.
*/
const commonmarkLanguage = /*@__PURE__*/mkLang(commonmark);
const extended = /*@__PURE__*/commonmark.configure([GFM, Subscript, Superscript, Emoji]);
/**
Language support for [GFM](https://github.github.com/gfm/) plus
subscript, superscript, and emoji syntax.
*/
const markdownLanguage = /*@__PURE__*/mkLang(extended);
function getCodeParser(languages, defaultLanguage) {
    return (info) => {
        if (info && languages) {
            let found = null;
            // Strip anything after whitespace
            info = /\S*/.exec(info)[0];
            if (typeof languages == "function")
                found = languages(info);
            else
                found = LanguageDescription.matchLanguageName(languages, info, true);
            if (found instanceof LanguageDescription)
                return found.support ? found.support.language.parser : ParseContext.getSkippingParser(found.load());
            else if (found)
                return found.parser;
        }
        return defaultLanguage ? defaultLanguage.parser : null;
    };
}

class Context {
    constructor(node, from, to, spaceBefore, spaceAfter, type, item) {
        this.node = node;
        this.from = from;
        this.to = to;
        this.spaceBefore = spaceBefore;
        this.spaceAfter = spaceAfter;
        this.type = type;
        this.item = item;
    }
    blank(maxWidth, trailing = true) {
        let result = this.spaceBefore + (this.node.name == "Blockquote" ? ">" : "");
        if (maxWidth != null) {
            while (result.length < maxWidth)
                result += " ";
            return result;
        }
        else {
            for (let i = this.to - this.from - result.length - this.spaceAfter.length; i > 0; i--)
                result += " ";
            return result + (trailing ? this.spaceAfter : "");
        }
    }
    marker(doc, add) {
        let number = this.node.name == "OrderedList" ? String((+itemNumber(this.item, doc)[2] + add)) : "";
        return this.spaceBefore + number + this.type + this.spaceAfter;
    }
}
function getContext(node, doc) {
    let nodes = [];
    for (let cur = node; cur && cur.name != "Document"; cur = cur.parent) {
        if (cur.name == "ListItem" || cur.name == "Blockquote" || cur.name == "FencedCode")
            nodes.push(cur);
    }
    let context = [];
    for (let i = nodes.length - 1; i >= 0; i--) {
        let node = nodes[i], match;
        let line = doc.lineAt(node.from), startPos = node.from - line.from;
        if (node.name == "FencedCode") {
            context.push(new Context(node, startPos, startPos, "", "", "", null));
        }
        else if (node.name == "Blockquote" && (match = /^[ \t]*>( ?)/.exec(line.text.slice(startPos)))) {
            context.push(new Context(node, startPos, startPos + match[0].length, "", match[1], ">", null));
        }
        else if (node.name == "ListItem" && node.parent.name == "OrderedList" &&
            (match = /^([ \t]*)\d+([.)])([ \t]*)/.exec(line.text.slice(startPos)))) {
            let after = match[3], len = match[0].length;
            if (after.length >= 4) {
                after = after.slice(0, after.length - 4);
                len -= 4;
            }
            context.push(new Context(node.parent, startPos, startPos + len, match[1], after, match[2], node));
        }
        else if (node.name == "ListItem" && node.parent.name == "BulletList" &&
            (match = /^([ \t]*)([-+*])([ \t]{1,4}\[[ xX]\])?([ \t]+)/.exec(line.text.slice(startPos)))) {
            let after = match[4], len = match[0].length;
            if (after.length > 4) {
                after = after.slice(0, after.length - 4);
                len -= 4;
            }
            let type = match[2];
            if (match[3])
                type += match[3].replace(/[xX]/, ' ');
            context.push(new Context(node.parent, startPos, startPos + len, match[1], after, type, node));
        }
    }
    return context;
}
function itemNumber(item, doc) {
    return /^(\s*)(\d+)(?=[.)])/.exec(doc.sliceString(item.from, item.from + 10));
}
function renumberList(after, doc, changes, offset = 0) {
    for (let prev = -1, node = after;;) {
        if (node.name == "ListItem") {
            let m = itemNumber(node, doc);
            let number = +m[2];
            if (prev >= 0) {
                if (number != prev + 1)
                    return;
                changes.push({ from: node.from + m[1].length, to: node.from + m[0].length, insert: String(prev + 2 + offset) });
            }
            prev = number;
        }
        let next = node.nextSibling;
        if (!next)
            break;
        node = next;
    }
}
/**
This command, when invoked in Markdown context with cursor
selection(s), will create a new line with the markup for
blockquotes and lists that were active on the old line. If the
cursor was directly after the end of the markup for the old line,
trailing whitespace and list markers are removed from that line.

The command does nothing in non-Markdown context, so it should
not be used as the only binding for Enter (even in a Markdown
document, HTML and code regions might use a different language).
*/
const insertNewlineContinueMarkup = ({ state, dispatch }) => {
    let tree = syntaxTree(state), { doc } = state;
    let dont = null, changes = state.changeByRange(range => {
        if (!range.empty || !markdownLanguage.isActiveAt(state, range.from))
            return dont = { range };
        let pos = range.from, line = doc.lineAt(pos);
        let context = getContext(tree.resolveInner(pos, -1), doc);
        while (context.length && context[context.length - 1].from > pos - line.from)
            context.pop();
        if (!context.length)
            return dont = { range };
        let inner = context[context.length - 1];
        if (inner.to - inner.spaceAfter.length > pos - line.from)
            return dont = { range };
        let emptyLine = pos >= (inner.to - inner.spaceAfter.length) && !/\S/.test(line.text.slice(inner.to));
        // Empty line in list
        if (inner.item && emptyLine) {
            // First list item or blank line before: delete a level of markup
            if (inner.node.firstChild.to >= pos ||
                line.from > 0 && !/[^\s>]/.test(doc.lineAt(line.from - 1).text)) {
                let next = context.length > 1 ? context[context.length - 2] : null;
                let delTo, insert = "";
                if (next && next.item) { // Re-add marker for the list at the next level
                    delTo = line.from + next.from;
                    insert = next.marker(doc, 1);
                }
                else {
                    delTo = line.from + (next ? next.to : 0);
                }
                let changes = [{ from: delTo, to: pos, insert }];
                if (inner.node.name == "OrderedList")
                    renumberList(inner.item, doc, changes, -2);
                if (next && next.node.name == "OrderedList")
                    renumberList(next.item, doc, changes);
                return { range: EditorSelection.cursor(delTo + insert.length), changes };
            }
            else { // Move this line down
                let insert = "";
                for (let i = 0, e = context.length - 2; i <= e; i++) {
                    insert += context[i].blank(i < e ? context[i + 1].from - insert.length : null, i < e);
                }
                insert += state.lineBreak;
                return { range: EditorSelection.cursor(pos + insert.length), changes: { from: line.from, insert } };
            }
        }
        if (inner.node.name == "Blockquote" && emptyLine && line.from) {
            let prevLine = doc.lineAt(line.from - 1), quoted = />\s*$/.exec(prevLine.text);
            // Two aligned empty quoted lines in a row
            if (quoted && quoted.index == inner.from) {
                let changes = state.changes([{ from: prevLine.from + quoted.index, to: prevLine.to },
                    { from: line.from + inner.from, to: line.to }]);
                return { range: range.map(changes), changes };
            }
        }
        let changes = [];
        if (inner.node.name == "OrderedList")
            renumberList(inner.item, doc, changes);
        let continued = inner.item && inner.item.from < line.from;
        let insert = "";
        // If not dedented
        if (!continued || /^[\s\d.)\-+*>]*/.exec(line.text)[0].length >= inner.to) {
            for (let i = 0, e = context.length - 1; i <= e; i++) {
                insert += i == e && !continued ? context[i].marker(doc, 1)
                    : context[i].blank(i < e ? context[i + 1].from - insert.length : null);
            }
        }
        let from = pos;
        while (from > line.from && /\s/.test(line.text.charAt(from - line.from - 1)))
            from--;
        insert = state.lineBreak + insert;
        changes.push({ from, to: pos, insert });
        return { range: EditorSelection.cursor(from + insert.length), changes };
    });
    if (dont)
        return false;
    dispatch(state.update(changes, { scrollIntoView: true, userEvent: "input" }));
    return true;
};
function isMark(node) {
    return node.name == "QuoteMark" || node.name == "ListMark";
}
function contextNodeForDelete(tree, pos) {
    let node = tree.resolveInner(pos, -1), scan = pos;
    if (isMark(node)) {
        scan = node.from;
        node = node.parent;
    }
    for (let prev; prev = node.childBefore(scan);) {
        if (isMark(prev)) {
            scan = prev.from;
        }
        else if (prev.name == "OrderedList" || prev.name == "BulletList") {
            node = prev.lastChild;
            scan = node.to;
        }
        else {
            break;
        }
    }
    return node;
}
/**
This command will, when invoked in a Markdown context with the
cursor directly after list or blockquote markup, delete one level
of markup. When the markup is for a list, it will be replaced by
spaces on the first invocation (a further invocation will delete
the spaces), to make it easy to continue a list.

When not after Markdown block markup, this command will return
false, so it is intended to be bound alongside other deletion
commands, with a higher precedence than the more generic commands.
*/
const deleteMarkupBackward = ({ state, dispatch }) => {
    let tree = syntaxTree(state);
    let dont = null, changes = state.changeByRange(range => {
        let pos = range.from, { doc } = state;
        if (range.empty && markdownLanguage.isActiveAt(state, range.from)) {
            let line = doc.lineAt(pos);
            let context = getContext(contextNodeForDelete(tree, pos), doc);
            if (context.length) {
                let inner = context[context.length - 1];
                let spaceEnd = inner.to - inner.spaceAfter.length + (inner.spaceAfter ? 1 : 0);
                // Delete extra trailing space after markup
                if (pos - line.from > spaceEnd && !/\S/.test(line.text.slice(spaceEnd, pos - line.from)))
                    return { range: EditorSelection.cursor(line.from + spaceEnd),
                        changes: { from: line.from + spaceEnd, to: pos } };
                if (pos - line.from == spaceEnd &&
                    // Only apply this if we're on the line that has the
                    // construct's syntax, or there's only indentation in the
                    // target range
                    (!inner.item || line.from <= inner.item.from || !/\S/.test(line.text.slice(0, inner.to)))) {
                    let start = line.from + inner.from;
                    // Replace a list item marker with blank space
                    if (inner.item && inner.node.from < inner.item.from && /\S/.test(line.text.slice(inner.from, inner.to)))
                        return { range, changes: { from: start, to: line.from + inner.to, insert: inner.blank(inner.to - inner.from) } };
                    // Delete one level of indentation
                    if (start < pos)
                        return { range: EditorSelection.cursor(start), changes: { from: start, to: pos } };
                }
            }
        }
        return dont = { range };
    });
    if (dont)
        return false;
    dispatch(state.update(changes, { scrollIntoView: true, userEvent: "delete" }));
    return true;
};

/**
A small keymap with Markdown-specific bindings. Binds Enter to
[`insertNewlineContinueMarkup`](https://codemirror.net/6/docs/ref/#lang-markdown.insertNewlineContinueMarkup)
and Backspace to
[`deleteMarkupBackward`](https://codemirror.net/6/docs/ref/#lang-markdown.deleteMarkupBackward).
*/
const markdownKeymap = [
    { key: "Enter", run: insertNewlineContinueMarkup },
    { key: "Backspace", run: deleteMarkupBackward }
];
const htmlNoMatch = /*@__PURE__*/html({ matchClosingTags: false });
/**
Markdown language support.
*/
function markdown(config = {}) {
    let { codeLanguages, defaultCodeLanguage, addKeymap = true, base: { parser } = commonmarkLanguage, completeHTMLTags = true } = config;
    if (!(parser instanceof MarkdownParser))
        throw new RangeError("Base parser provided to `markdown` should be a Markdown parser");
    let extensions = config.extensions ? [config.extensions] : [];
    let support = [htmlNoMatch.support], defaultCode;
    if (defaultCodeLanguage instanceof LanguageSupport) {
        support.push(defaultCodeLanguage.support);
        defaultCode = defaultCodeLanguage.language;
    }
    else if (defaultCodeLanguage) {
        defaultCode = defaultCodeLanguage;
    }
    let codeParser = codeLanguages || defaultCode ? getCodeParser(codeLanguages, defaultCode) : undefined;
    extensions.push(parseCode({ codeParser, htmlParser: htmlNoMatch.language.parser }));
    if (addKeymap)
        support.push(Prec.high(keymap.of(markdownKeymap)));
    let lang = mkLang(parser.configure(extensions));
    if (completeHTMLTags)
        support.push(lang.data.of({ autocomplete: htmlTagCompletion }));
    return new LanguageSupport(lang, support);
}
function htmlTagCompletion(context) {
    let { state, pos } = context, m = /<[:\-\.\w\u00b7-\uffff]*$/.exec(state.sliceDoc(pos - 25, pos));
    if (!m)
        return null;
    let tree = syntaxTree(state).resolveInner(pos, -1);
    while (tree && !tree.type.isTop) {
        if (tree.name == "CodeBlock" || tree.name == "FencedCode" || tree.name == "ProcessingInstructionBlock" ||
            tree.name == "CommentBlock" || tree.name == "Link" || tree.name == "Image")
            return null;
        tree = tree.parent;
    }
    return {
        from: pos - m[0].length, to: pos,
        options: htmlTagCompletions(),
        validFor: /^<[:\-\.\w\u00b7-\uffff]*$/
    };
}
let _tagCompletions = null;
function htmlTagCompletions() {
    if (_tagCompletions)
        return _tagCompletions;
    let result = htmlCompletionSource(new CompletionContext(EditorState.create({ extensions: htmlNoMatch }), 0, true));
    return _tagCompletions = result ? result.options : [];
}

export { commonmarkLanguage, deleteMarkupBackward, insertNewlineContinueMarkup, markdown, markdownKeymap, markdownLanguage };
