/*---------------------------------------------------------------------------------------------
 *  Copyright (c) Microsoft Corporation. All rights reserved.
 *  Licensed under the Source EULA. See License.txt in the project root for license information.
 *--------------------------------------------------------------------------------------------*/

import * as assert from 'assert';
import 'mocha';
import * as vscode from 'vscode';
import { MdLinkProvider } from '../languageFeatures/documentLinkProvider';
import { MdReferencesProvider } from '../languageFeatures/references';
import { githubSlugifier } from '../slugify';
import { InMemoryDocument } from '../util/inMemoryDocument';
import { MdWorkspaceContents } from '../workspaceContents';
import { createNewMarkdownEngine } from './engine';
import { InMemoryWorkspaceMarkdownDocuments } from './inMemoryWorkspace';
import { joinLines, noopToken, workspacePath } from './util';


function getReferences(doc: InMemoryDocument, pos: vscode.Position, workspaceContents: MdWorkspaceContents) {
	const engine = createNewMarkdownEngine();
	const linkProvider = new MdLinkProvider(engine);
	const provider = new MdReferencesProvider(linkProvider, workspaceContents, engine, githubSlugifier);
	return provider.provideReferences(doc, pos, { includeDeclaration: true }, noopToken);
}

function assertReferencesEqual(actualRefs: readonly vscode.Location[], ...expectedRefs: { uri: vscode.Uri; line: number; startCharacter?: number; endCharacter?: number }[]) {
	assert.strictEqual(actualRefs.length, expectedRefs.length, `Reference counts should match`);

	for (let i = 0; i < actualRefs.length; ++i) {
		const actual = actualRefs[i];
		const expected = expectedRefs[i];
		assert.strictEqual(actual.uri.toString(), expected.uri.toString(), `Ref '${i}' has expected document`);
		assert.strictEqual(actual.range.start.line, expected.line, `Ref '${i}' has expected start line`);
		assert.strictEqual(actual.range.end.line, expected.line, `Ref '${i}' has expected end line`);
		if (typeof expected.startCharacter !== 'undefined') {
			assert.strictEqual(actual.range.start.character, expected.startCharacter, `Ref '${i}' has expected start character`);
		}
		if (typeof expected.endCharacter !== 'undefined') {
			assert.strictEqual(actual.range.end.character, expected.endCharacter, `Ref '${i}' has expected end character`);
		}
	}
}

suite('markdown: find all references', () => {
	test('Should not return references when not on header or link', async () => {
		const doc = new InMemoryDocument(workspacePath('doc.md'), joinLines(
			`# abc`,
			``,
			`[link 1](#abc)`,
			`text`,
		));

		{
			const refs = await getReferences(doc, new vscode.Position(1, 0), new InMemoryWorkspaceMarkdownDocuments([doc]));
			assert.deepStrictEqual(refs, []);
		}
		{
			const refs = await getReferences(doc, new vscode.Position(3, 2), new InMemoryWorkspaceMarkdownDocuments([doc]));
			assert.deepStrictEqual(refs, []);
		}
	});

	test('Should find references from header within same file', async () => {
		const uri = workspacePath('doc.md');
		const doc = new InMemoryDocument(uri, joinLines(
			`# abc`,
			``,
			`[link 1](#abc)`,
			`[not link](#noabc)`,
			`[link 2](#abc)`,
		));
		const refs = await getReferences(doc, new vscode.Position(0, 3), new InMemoryWorkspaceMarkdownDocuments([doc]));
		assertReferencesEqual(refs!,
			{ uri, line: 0 },
			{ uri, line: 2 },
			{ uri, line: 4 },
		);
	});

	test('Should not return references when on link text', async () => {
		const doc = new InMemoryDocument(workspacePath('doc.md'), joinLines(
			`[ref](#abc)`,
			`[ref]: http://example.com`,
		));

		const refs = await getReferences(doc, new vscode.Position(0, 1), new InMemoryWorkspaceMarkdownDocuments([doc]));
		assert.deepStrictEqual(refs, []);
	});

	test('Should find references using normalized slug', async () => {
		const doc = new InMemoryDocument(workspacePath('doc.md'), joinLines(
			`# a B c`,
			`[simple](#a-b-c)`,
			`[start underscore](#_a-b-c)`,
			`[different case](#a-B-C)`,
		));

		{
			// Trigger header
			const refs = await getReferences(doc, new vscode.Position(0, 0), new InMemoryWorkspaceMarkdownDocuments([doc]));
			assert.deepStrictEqual(refs!.length, 4);
		}
		{
			// Trigger on line 1
			const refs = await getReferences(doc, new vscode.Position(1, 12), new InMemoryWorkspaceMarkdownDocuments([doc]));
			assert.deepStrictEqual(refs!.length, 4);
		}
		{
			// Trigger on line 2
			const refs = await getReferences(doc, new vscode.Position(2, 24), new InMemoryWorkspaceMarkdownDocuments([doc]));
			assert.deepStrictEqual(refs!.length, 4);
		}
		{
			// Trigger on line 3
			const refs = await getReferences(doc, new vscode.Position(3, 20), new InMemoryWorkspaceMarkdownDocuments([doc]));
			assert.deepStrictEqual(refs!.length, 4);
		}
	});

	test('Should find references from header across files', async () => {
		const docUri = workspacePath('doc.md');
		const other1Uri = workspacePath('sub', 'other.md');
		const other2Uri = workspacePath('other2.md');

		const doc = new InMemoryDocument(docUri, joinLines(
			`# abc`,
			``,
			`[link 1](#abc)`,
		));
		const refs = await getReferences(doc, new vscode.Position(0, 3), new InMemoryWorkspaceMarkdownDocuments([
			doc,
			new InMemoryDocument(other1Uri, joinLines(
				`[not link](#abc)`,
				`[not link](/doc.md#abz)`,
				`[link](/doc.md#abc)`,
			)),
			new InMemoryDocument(other2Uri, joinLines(
				`[not link](#abc)`,
				`[not link](./doc.md#abz)`,
				`[link](./doc.md#abc)`,
			))
		]));

		assertReferencesEqual(refs!,
			{ uri: docUri, line: 0 }, // Header definition
			{ uri: docUri, line: 2 },
			{ uri: other1Uri, line: 2 },
			{ uri: other2Uri, line: 2 },
		);
	});

	test('Should find references from header to link definitions ', async () => {
		const uri = workspacePath('doc.md');
		const doc = new InMemoryDocument(uri, joinLines(
			`# abc`,
			``,
			`[bla]: #abc`
		));

		const refs = await getReferences(doc, new vscode.Position(0, 3), new InMemoryWorkspaceMarkdownDocuments([doc]));
		assertReferencesEqual(refs!,
			{ uri, line: 0 }, // Header definition
			{ uri, line: 2 },
		);
	});

	test('Should find header references from link definition', async () => {
		const uri = workspacePath('doc.md');
		const doc = new InMemoryDocument(uri, joinLines(
			`# A b C`,
			`[text][bla]`,
			`[bla]: #a-b-c`, // trigger here
		));

		const refs = await getReferences(doc, new vscode.Position(2, 9), new InMemoryWorkspaceMarkdownDocuments([doc]));
		assertReferencesEqual(refs!,
			{ uri, line: 0 }, // Header definition
			{ uri, line: 2 },
		);
	});

	test('Should find references from link within same file', async () => {
		const uri = workspacePath('doc.md');
		const doc = new InMemoryDocument(uri, joinLines(
			`# abc`,
			``,
			`[link 1](#abc)`,
			`[not link](#noabc)`,
			`[link 2](#abc)`,
		));

		const refs = await getReferences(doc, new vscode.Position(2, 10), new InMemoryWorkspaceMarkdownDocuments([doc]));
		assertReferencesEqual(refs!,
			{ uri, line: 0 }, // Header definition
			{ uri, line: 2 },
			{ uri, line: 4 },
		);
	});

	test('Should find references from link across files', async () => {
		const docUri = workspacePath('doc.md');
		const other1Uri = workspacePath('sub', 'other.md');
		const other2Uri = workspacePath('other2.md');

		const doc = new InMemoryDocument(docUri, joinLines(
			`# abc`,
			``,
			`[link 1](#abc)`,
		));
		const refs = await getReferences(doc, new vscode.Position(2, 10), new InMemoryWorkspaceMarkdownDocuments([
			doc,
			new InMemoryDocument(other1Uri, joinLines(
				`[not link](#abc)`,
				`[not link](/doc.md#abz)`,
				`[with ext](/doc.md#abc)`,
				`[without ext](/doc#abc)`,
			)),
			new InMemoryDocument(other2Uri, joinLines(
				`[not link](#abc)`,
				`[not link](./doc.md#abz)`,
				`[link](./doc.md#abc)`,
			))
		]));

		assertReferencesEqual(refs!,
			{ uri: docUri, line: 0 }, // Header definition
			{ uri: docUri, line: 2 },
			{ uri: other1Uri, line: 2 }, // Other with ext
			{ uri: other1Uri, line: 3 }, // Other without ext
			{ uri: other2Uri, line: 2 }, // Other2
		);
	});

	test('Should find references without requiring file extensions', async () => {
		const docUri = workspacePath('doc.md');
		const other1Uri = workspacePath('other.md');

		const doc = new InMemoryDocument(docUri, joinLines(
			`# a B c`,
			``,
			`[link 1](#a-b-c)`,
		));
		const refs = await getReferences(doc, new vscode.Position(2, 10), new InMemoryWorkspaceMarkdownDocuments([
			doc,
			new InMemoryDocument(other1Uri, joinLines(
				`[not link](#a-b-c)`,
				`[not link](/doc.md#a-b-z)`,
				`[with ext](/doc.md#a-b-c)`,
				`[without ext](/doc#a-b-c)`,
				`[rel with ext](./doc.md#a-b-c)`,
				`[rel without ext](./doc#a-b-c)`,
			)),
		]));

		assertReferencesEqual(refs!,
			{ uri: docUri, line: 0 }, // Header definition
			{ uri: docUri, line: 2 },
			{ uri: other1Uri, line: 2 }, // Other with ext
			{ uri: other1Uri, line: 3 }, // Other without ext
			{ uri: other1Uri, line: 4 }, // Other relative link with ext
			{ uri: other1Uri, line: 5 }, // Other relative link without ext
		);
	});

	test('Should find references from link across files when triggered on link without file extension', async () => {
		const docUri = workspacePath('doc.md');
		const other1Uri = workspacePath('sub', 'other.md');

		const doc = new InMemoryDocument(docUri, joinLines(
			`[with ext](./sub/other#header)`,
			`[without ext](./sub/other.md#header)`,
		));

		const refs = await getReferences(doc, new vscode.Position(0, 23), new InMemoryWorkspaceMarkdownDocuments([
			doc,
			new InMemoryDocument(other1Uri, joinLines(
				`pre`,
				`# header`,
				`post`,
			)),
		]));

		assertReferencesEqual(refs!,
			{ uri: other1Uri, line: 1 }, // Header definition
			{ uri: docUri, line: 0 },
			{ uri: docUri, line: 1 },
		);
	});

	test('Should include header references when triggered on file link', async () => {
		const docUri = workspacePath('doc.md');
		const otherUri = workspacePath('sub', 'other.md');

		const doc = new InMemoryDocument(docUri, joinLines(
			`[with ext](./sub/other)`,
			`[with ext](./sub/other#header)`,
			`[without ext](./sub/other.md#no-such-header)`,
		));

		const refs = await getReferences(doc, new vscode.Position(0, 15), new InMemoryWorkspaceMarkdownDocuments([
			doc,
			new InMemoryDocument(otherUri, joinLines(
				`pre`,
				`# header`, // Definition should not be included since we triggered on a file link
				`post`,
			)),
		]));

		assertReferencesEqual(refs!,
			{ uri: docUri, line: 0 },
			{ uri: docUri, line: 1 },
			{ uri: docUri, line: 2 },
		);
	});

	test('Should not include refs from other file to own header', async () => {
		const docUri = workspacePath('doc.md');
		const otherUri = workspacePath('sub', 'other.md');

		const doc = new InMemoryDocument(docUri, joinLines(
			`[other](./sub/other)`, // trigger here
		));

		const refs = await getReferences(doc, new vscode.Position(0, 15), new InMemoryWorkspaceMarkdownDocuments([
			doc,
			new InMemoryDocument(otherUri, joinLines(
				`# header`, // Definition should not be included since we triggered on a file link
				`[text](#header)`, // Ref should not be included since it is to own file
			)),
		]));

		assertReferencesEqual(refs!,
			{ uri: docUri, line: 0 },
		);
	});

	test('Should find explicit references to own file ', async () => {
		const uri = workspacePath('doc.md');
		const doc = new InMemoryDocument(uri, joinLines(
			`[bare](doc.md)`, // trigger here
			`[rel](./doc.md)`,
			`[abs](/doc.md)`,
		));

		const refs = await getReferences(doc, new vscode.Position(0, 12), new InMemoryWorkspaceMarkdownDocuments([doc]));
		assertReferencesEqual(refs!,
			{ uri, line: 0 },
			{ uri, line: 1 },
			{ uri, line: 2 },
		);
	});

	test('Should support finding references to http uri', async () => {
		const uri = workspacePath('doc.md');
		const doc = new InMemoryDocument(uri, joinLines(
			`[1](http://example.com)`,
			`[no](https://example.com)`,
			`[2](http://example.com)`,
			`[3]: http://example.com`,
		));

		const refs = await getReferences(doc, new vscode.Position(0, 13), new InMemoryWorkspaceMarkdownDocuments([doc]));
		assertReferencesEqual(refs!,
			{ uri, line: 0 },
			{ uri, line: 2 },
			{ uri, line: 3 },
		);
	});

	test('Should consider authority, scheme and paths when finding references to http uri', async () => {
		const uri = workspacePath('doc.md');
		const doc = new InMemoryDocument(uri, joinLines(
			`[1](http://example.com/cat)`,
			`[2](http://example.com)`,
			`[3](http://example.com/dog)`,
			`[4](http://example.com/cat/looong)`,
			`[5](http://example.com/cat)`,
			`[6](http://other.com/cat)`,
			`[7](https://example.com/cat)`,
		));

		const refs = await getReferences(doc, new vscode.Position(0, 13), new InMemoryWorkspaceMarkdownDocuments([doc]));
		assertReferencesEqual(refs!,
			{ uri, line: 0 },
			{ uri, line: 4 },
		);
	});

	test('Should support finding references to http uri across files', async () => {
		const uri1 = workspacePath('doc.md');
		const uri2 = workspacePath('doc2.md');
		const doc = new InMemoryDocument(uri1, joinLines(
			`[1](http://example.com)`,
			`[3]: http://example.com`,
		));

		const refs = await getReferences(doc, new vscode.Position(0, 13), new InMemoryWorkspaceMarkdownDocuments([
			doc,
			new InMemoryDocument(uri2, joinLines(
				`[other](http://example.com)`,
			))
		]));
		assertReferencesEqual(refs!,
			{ uri: uri1, line: 0 },
			{ uri: uri1, line: 1 },
			{ uri: uri2, line: 0 },
		);
	});

	test('Should support finding references to autolinked http links', async () => {
		const uri = workspacePath('doc.md');
		const doc = new InMemoryDocument(uri, joinLines(
			`[1](http://example.com)`,
			`<http://example.com>`,
		));

		const refs = await getReferences(doc, new vscode.Position(0, 13), new InMemoryWorkspaceMarkdownDocuments([doc]));
		assertReferencesEqual(refs!,
			{ uri, line: 0 },
			{ uri, line: 1 },
		);
	});

	test('Should distinguish between references to file and to header within file', async () => {
		const docUri = workspacePath('doc.md');
		const other1Uri = workspacePath('sub', 'other.md');

		const doc = new InMemoryDocument(docUri, joinLines(
			`# abc`,
			``,
			`[link 1](#abc)`,
		));
		const otherDoc = new InMemoryDocument(other1Uri, joinLines(
			`[link](/doc.md#abc)`,
			`[link no text](/doc#abc)`,
		));
		const workspaceContents = new InMemoryWorkspaceMarkdownDocuments([
			doc,
			otherDoc,
		]);
		{
			// Check refs to header fragment
			const headerRefs = await getReferences(otherDoc, new vscode.Position(0, 16), workspaceContents);
			assertReferencesEqual(headerRefs!,
				{ uri: docUri, line: 0 }, // Header definition
				{ uri: docUri, line: 2 },
				{ uri: other1Uri, line: 0 },
				{ uri: other1Uri, line: 1 },
			);
		}
		{
			// Check refs to file itself from link with ext
			const fileRefs = await getReferences(otherDoc, new vscode.Position(0, 9), workspaceContents);
			assertReferencesEqual(fileRefs!,
				{ uri: other1Uri, line: 0, endCharacter: 14 },
				{ uri: other1Uri, line: 1, endCharacter: 19 },
			);
		}
		{
			// Check refs to file itself from link without ext
			const fileRefs = await getReferences(otherDoc, new vscode.Position(1, 17), workspaceContents);
			assertReferencesEqual(fileRefs!,
				{ uri: other1Uri, line: 0 },
				{ uri: other1Uri, line: 1 },
			);
		}
	});

	test('Should support finding references to unknown file', async () => {
		const uri1 = workspacePath('doc1.md');
		const doc1 = new InMemoryDocument(uri1, joinLines(
			`![img](/images/more/image.png)`,
			``,
			`[ref]: /images/more/image.png`,
		));

		const uri2 = workspacePath('sub', 'doc2.md');
		const doc2 = new InMemoryDocument(uri2, joinLines(
			`![img](/images/more/image.png)`,
		));


		const refs = await getReferences(doc1, new vscode.Position(0, 10), new InMemoryWorkspaceMarkdownDocuments([doc1, doc2]));
		assertReferencesEqual(refs!,
			{ uri: uri1, line: 0 },
			{ uri: uri1, line: 2 },
			{ uri: uri2, line: 0 },
		);
	});

	suite('Reference links', () => {
		test('Should find reference links within file from link', async () => {
			const docUri = workspacePath('doc.md');
			const doc = new InMemoryDocument(docUri, joinLines(
				`[link 1][abc]`, // trigger here
				``,
				`[abc]: https://example.com`,
			));

			const refs = await getReferences(doc, new vscode.Position(0, 12), new InMemoryWorkspaceMarkdownDocuments([doc]));
			assertReferencesEqual(refs!,
				{ uri: docUri, line: 0 },
				{ uri: docUri, line: 2 },
			);
		});

		test('Should find reference links using shorthand', async () => {
			const docUri = workspacePath('doc.md');
			const doc = new InMemoryDocument(docUri, joinLines(
				`[ref]`, // trigger 1
				``,
				`[yes][ref]`, // trigger 2
				``,
				`[ref]: /Hello.md` // trigger 3
			));

			{
				const refs = await getReferences(doc, new vscode.Position(0, 2), new InMemoryWorkspaceMarkdownDocuments([doc]));
				assertReferencesEqual(refs!,
					{ uri: docUri, line: 0 },
					{ uri: docUri, line: 2 },
					{ uri: docUri, line: 4 },
				);
			}
			{
				const refs = await getReferences(doc, new vscode.Position(2, 7), new InMemoryWorkspaceMarkdownDocuments([doc]));
				assertReferencesEqual(refs!,
					{ uri: docUri, line: 0 },
					{ uri: docUri, line: 2 },
					{ uri: docUri, line: 4 },
				);
			}
			{
				const refs = await getReferences(doc, new vscode.Position(4, 2), new InMemoryWorkspaceMarkdownDocuments([doc]));
				assertReferencesEqual(refs!,
					{ uri: docUri, line: 0 },
					{ uri: docUri, line: 2 },
					{ uri: docUri, line: 4 },
				);
			}
		});

		test('Should find reference links within file from definition', async () => {
			const docUri = workspacePath('doc.md');
			const doc = new InMemoryDocument(docUri, joinLines(
				`[link 1][abc]`,
				``,
				`[abc]: https://example.com`, // trigger here
			));

			const refs = await getReferences(doc, new vscode.Position(2, 3), new InMemoryWorkspaceMarkdownDocuments([doc]));
			assertReferencesEqual(refs!,
				{ uri: docUri, line: 0 },
				{ uri: docUri, line: 2 },
			);
		});

		test('Should not find reference links across files', async () => {
			const docUri = workspacePath('doc.md');
			const doc = new InMemoryDocument(docUri, joinLines(
				`[link 1][abc]`,
				``,
				`[abc]: https://example.com`,
			));

			const refs = await getReferences(doc, new vscode.Position(0, 12), new InMemoryWorkspaceMarkdownDocuments([
				doc,
				new InMemoryDocument(workspacePath('other.md'), joinLines(
					`[link 1][abc]`,
					``,
					`[abc]: https://example.com?bad`,
				))
			]));
			assertReferencesEqual(refs!,
				{ uri: docUri, line: 0 },
				{ uri: docUri, line: 2 },
			);
		});
	});
});