'use strict';

import shared from '../../utils/shared';

const defaultGroups = [
  // Side effect imports.
  ['^\\u0000'],
  // Node.js builtins prefixed with `node:`.
  ['^node:'],
  // Packages.
  // Things that start with a letter (or digit or underscore), or `@` followed by a letter.
  ['^@?\\w'],
  // Absolute imports and other imports such as Vue-style `@/foo`.
  // Anything not matched in another group.
  ['^'],
  // Relative imports.
  // Anything that starts with a dot.
  ['^\\.']
];

function maybeReportChunkSorting(chunk: any, context: any, outerGroups: any) {
  const sourceCode = context.getSourceCode();
  const items = shared.getImportExportItems(chunk, sourceCode, isSideEffectImport, getSpecifiers);
  const sortedItems = makeSortedItems(items, outerGroups);
  const sorted = shared.printSortedItems(sortedItems, items, sourceCode);
  const { start } = items[0];
  const { end } = items[items.length - 1];
  shared.maybeReportSorting(context, sorted, start, end);
}

function makeSortedItems(items: any, outerGroups: any) {
  const itemGroups = outerGroups.map((groups: any) => groups.map((regex: any) => ({ regex, items: [] })));
  const rest = [];

  for (const item of items) {
    const { originalSource } = item.source;
    const source = item.isSideEffectImport ? `\0${originalSource}` : item.source.kind !== 'value' ? `${originalSource}\0` : originalSource;
    const [matchedGroup] = shared
      .flatMap(itemGroups, (groups: any) => groups.map((group: any) => [group, group.regex.exec(source)]))
      .reduce(
        ([group, longestMatch]: any, [nextGroup, nextMatch]: any) =>
          nextMatch != null && (longestMatch == null || nextMatch[0].length > longestMatch[0].length)
            ? [nextGroup, nextMatch]
            : [group, longestMatch],
        [undefined, undefined]
      );
    if (matchedGroup == null) {
      rest.push(item);
    } else {
      matchedGroup.items.push(item);
    }
  }

  return itemGroups
    .concat([[{ regex: /^/, items: rest }]])
    .map((groups: any) => groups.filter((group: any) => group.items.length > 0))
    .filter((groups: any) => groups.length > 0)
    .map((groups: any) => groups.map((group: any) => shared.sortImportExportItems(group.items)));
}

// Exclude "ImportDefaultSpecifier" – the "def" in `import def, {a, b}`.
function getSpecifiers(importNode: any) {
  return importNode.specifiers.filter((node: any) => isImportSpecifier(node));
}

// Full import statement.
function isImport(node: any) {
  return node.type === 'ImportDeclaration';
}

// import def, { a, b as c, type d } from "A"
//               ^  ^^^^^^  ^^^^^^
function isImportSpecifier(node: any) {
  return node.type === 'ImportSpecifier';
}

// import "setup"
// But not: import {} from "setup"
// And not: import type {} from "setup"
function isSideEffectImport(importNode: any, sourceCode: any) {
  return (
    importNode.specifiers.length === 0 &&
    (!importNode.importKind || importNode.importKind === 'value') &&
    !shared.isPunctuator(sourceCode.getFirstToken(importNode, { skip: 1 }), '{')
  );
}

export const importsRule = {
  meta: {
    type: 'layout',
    fixable: 'code',
    schema: [
      { type: 'object', properties: { groups: { type: 'array', items: { type: 'array', items: { type: 'string' } } } }, additionalProperties: false }
    ],
    docs: { url: 'https://github.com/lydell/eslint-plugin-simple-import-sort#sort-order' },
    messages: { sort: 'Run autofix to sort these imports!' }
  },
  create: (context: any) => {
    const { groups: rawGroups = defaultGroups } = context.options[0] || {};
    const outerGroups = rawGroups.map((groups: any) => groups.map((item: any) => RegExp(item, 'u')));

    return {
      Program: (programNode: any) => {
        for (const chunk of shared.extractChunks(programNode, (node: any) => (isImport(node) ? 'PartOfChunk' : 'NotPartOfChunk'))) {
          maybeReportChunkSorting(chunk, context, outerGroups);
        }
      }
    };
  }
};