export function getConfiguredLangId(modelService: IModelService, modeService: IModeService, resource: uri): string | null {
	let configuredLangId: string | null = null;
	if (resource) {
		let modeId: string | null = null;

		// Data URI: check for encoded metadata
		if (resource.scheme === Schemas.data) {
			const metadata = DataUri.parseMetaData(resource);
			const mime = metadata.get(DataUri.META_DATA_MIME);

			if (mime) {
				modeId = modeService.getModeId(mime);
			}
		}

		// Any other URI: check for model if existing
		else {
			const model = modelService.getModel(resource);
			if (model) {
				modeId = model.getLanguageIdentifier().language;
			}
		}

		if (modeId && modeId !== PLAINTEXT_MODE_ID) {
			configuredLangId = modeId; // only take if the mode is specific (aka no just plain text)
		}
	}

	return configuredLangId;
}

export function detectModeId(modelService: IModelService, modeService: IModeService, resource: uri): string | null {
	if (!resource) {
		return null; // we need a resource at least
	}

	let modeId: string | null = null;

	// Data URI: check for encoded metadata
	if (resource.scheme === Schemas.data) {
		const metadata = DataUri.parseMetaData(resource);
		const mime = metadata.get(DataUri.META_DATA_MIME);

		if (mime) {
			modeId = modeService.getModeId(mime);
		}
	}

	// Any other URI: check for model if existing
	else {
		const model = modelService.getModel(resource);
		if (model) {
			modeId = model.getModeId();
		}
	}

	// only take if the mode is specific (aka no just plain text)
	if (modeId && modeId !== PLAINTEXT_MODE_ID) {
		return modeId;
	}

	// otherwise fallback to path based detection
	let path: string | undefined;
	if (resource.scheme === Schemas.data) {
		const metadata = DataUri.parseMetaData(resource);
		path = metadata.get(DataUri.META_DATA_LABEL);
	} else {
		path = resource.path.toLowerCase();
	}

	if (path) {
		return modeService.getModeIdByFilepathOrFirstLine(path);
	}

	return null; // finally - we do not know the mode id
}

export function getIconClasses(modelService: IModelService, modeService: IModeService, resource: uri | undefined, fileKind?: FileKind): string[] {

	// we always set these base classes even if we do not have a path
	const classes = fileKind === FileKind.ROOT_FOLDER ? ['rootfolder-icon'] : fileKind === FileKind.FOLDER ? ['folder-icon'] : ['file-icon'];
	if (resource) {

		// Get the path and name of the resource. For data-URIs, we need to parse specially
		let name: string | undefined;
		let path: string | undefined;
		if (resource.scheme === Schemas.data) {
			const metadata = DataUri.parseMetaData(resource);
			name = metadata.get(DataUri.META_DATA_LABEL);
			path = name;
		} else {
			name = cssEscape(basenameOrAuthority(resource).toLowerCase());
			path = resource.path.toLowerCase();
		}

		// Folders
		if (fileKind === FileKind.FOLDER) {
			classes.push(`${name}-name-folder-icon`);
		}

		// Files
		else {

			// Name & Extension(s)
			if (name) {
				classes.push(`${name}-name-file-icon`);
				const dotSegments = name.split('.');
				for (let i = 1; i < dotSegments.length; i++) {
					classes.push(`${dotSegments.slice(i).join('.')}-ext-file-icon`); // add each combination of all found extensions if more than one
				}
				classes.push(`ext-file-icon`); // extra segment to increase file-ext score
			}

			// Configured Language
			let configuredLangId: string | null = getConfiguredLangId(modelService, modeService, resource);
			configuredLangId = configuredLangId || (path ? modeService.getModeIdByFilepathOrFirstLine(path) : null);
			if (configuredLangId) {
				classes.push(`${cssEscape(configuredLangId)}-lang-file-icon`);
			}
		}
	}
	return classes;
}