thi-ng/umbrella

import type { BigType, Keys, Nullable } from "@thi.ng/api";
import { isArray } from "@thi.ng/checks/is-array";
import { isPlainObject } from "@thi.ng/checks/is-plain-object";
import { isString } from "@thi.ng/checks/is-string";
import { split } from "@thi.ng/strings/split";
import { wordWrapLine, wordWrapLines } from "@thi.ng/strings/word-wrap";
import type {
    CodeGenOpts,
    Field,
    InjectedBody,
    Struct,
    TopLevelType,
    TypeColl,
    Union,
    WasmPrim,
    WasmPrim32,
} from "../api.js";

/**
 * Returns true iff `x` is a {@link WasmPrim32}.
 *
 * @param x
 */
export const isNumeric = (x: string): x is WasmPrim32 =>
    /^(([iu](8|16|32))|(f(32|64)))$/.test(x);

/**
 * Returns true iff `x` is a `i64` or `u64`.
 *
 * @param x
 */
export const isBigNumeric = (x: string): x is BigType => /^[iu]64$/.test(x);

export const isSizeT = (x: string): x is "isize" | "usize" =>
    /^[iu]size$/.test(x);

/**
 * Returns true iff `x` is a {@link WasmPrim}.
 *
 * @param x
 */
export const isWasmPrim = (x: string): x is WasmPrim =>
    isNumeric(x) || isBigNumeric(x);

export const isWasmString = (x: string): x is "string" => x === "string";

export const isPadding = (f: Pick<Field, "pad">) => f.pad != null && f.pad > 0;

export const isPointer = (x: Field["tag"]): x is "ptr" => x === "ptr";

export const isFuncPointer = (type: string, coll: TypeColl) =>
    coll[type]?.type === "funcptr";

export const isEnum = (type: string, coll: TypeColl) =>
    coll[type]?.type === "enum";

export const isExternal = (type: string, coll: TypeColl) =>
    coll[type]?.type === "ext";

export const isSlice = (x: Field["tag"]): x is "slice" => x === "slice";

export const isOpaque = (x: string): x is "opaque" => x === "opaque";

/**
 * Returns true iff the struct field is a pointer, slice or "string" type
 *
 * @param f
 */
export const isPointerLike = (f: Field, coll: TypeColl) =>
    isPointer(f.tag) ||
    isSlice(f.tag) ||
    isWasmString(f.type) ||
    isOpaque(f.type) ||
    isFuncPointer(f.type, coll);

/**
 * Returns true if `type` is "slice".
 *
 * @param type
 */
export const isStringSlice = (
    type: CodeGenOpts["stringType"]
): type is "slice" => type === "slice";

export const isStruct = (x: TopLevelType): x is Struct => x.type === "struct";

export const isUnion = (x: TopLevelType): x is Union => x.type === "union";

/**
 * Returns true if `x` is a struct or union and contains string fields.
 *
 * @param x
 */
export const hasStringFields = (x: TopLevelType) => {
    if (!isStruct(x) || isUnion(x)) return false;
    return x.fields.some((f) => f.type === "string");
};

/**
 * Returns true if the given type collection contains structs or unions with
 * string fields.
 *
 * @param coll
 */
export const usesStrings = (coll: TypeColl) =>
    Object.values(coll).some(hasStringFields);

/**
 * Returns filtered array of struct fields of with "ptr" tag or function
 * pointers.
 *
 * @param fields
 *
 * @internal
 */
export const pointerFields = (fields: Field[]) =>
    fields.filter((f) => isPointer(f.tag));

/**
 * Returns filtered array of struct fields of only "string" fields.
 *
 * @param fields
 *
 * @internal
 */
export const stringFields = (fields: Field[]) =>
    fields.filter((f) => isWasmString(f.type) && f.tag !== "ptr");

export const sliceTypes = (coll: TypeColl) =>
    new Set(
        Object.values(coll)
            .flatMap((x) => (isStruct(x) || isUnion(x) ? x.fields : []))
            .map((x) => (x.tag === "slice" ? x.type : null))
            .filter((x) => !!x)
    );

/**
 * Returns enum identifier formatted according to given opts.
 *
 * @param opts
 * @param name
 *
 * @internal
 */
export const enumName = (opts: CodeGenOpts, name: string) =>
    opts.uppercaseEnums ? name.toUpperCase() : name;

/**
 * Returns given field's default value (or undefined). The `lang` ID is required
 * to obtain the language specific value if the default is given as object.
 *
 * @param f
 * @param lang
 */
export const defaultValue = (f: Field, lang: string) =>
    f.default !== undefined
        ? isPlainObject(f.default)
            ? f.default[lang]
            : f.default
        : undefined;

/**
 * Takes an array of strings or splits given string into lines, word wraps and
 * then prefixes each line with given `width` and `prefix`. Returns array of new
 * lines.
 *
 * @param prefix
 * @param str
 * @param width
 */
export const prefixLines = (
    prefix: string,
    str: string | string[],
    width: number
) =>
    (isString(str)
        ? wordWrapLines(str, { width: width - prefix.length })
        : str.flatMap((x) => wordWrapLine(x, { width: width - prefix.length }))
    ).map((line) => prefix + line);

export const ensureLines = (
    src: string | string[] | InjectedBody,
    key?: keyof InjectedBody
): Iterable<string> =>
    isString(src)
        ? split(src)
        : isArray(src)
        ? src
        : key
        ? src[key]
            ? ensureLines(src[key]!, key)
            : []
        : [];

export const ensureStringArray = (src: string | string[]) =>
    isString(src) ? [src] : src;

/**
 * Yields iterator of given lines, each with applied indentation based on given
 * scope regexp's which are applied to each line to increase or decrease
 * indentation level (the initial indentation level can be specified via
 * optional `level` arg, default 0). If `scopeStart` succeeds, the indent is
 * increased for the _next_ line. If `scopeEnd` succeeds the level is decreased
 * for the _current_ line. ...
 *
 * @param lines
 * @param indent
 * @param scopeStart
 * @param scopeEnd
 * @param level
 */
export function* withIndentation(
    lines: string[],
    indent: string,
    scopeStart: RegExp,
    scopeEnd: RegExp,
    level = 0
) {
    const stack: string[] = new Array(level).fill(indent);
    for (let l of lines) {
        scopeEnd.test(l) && stack.pop();
        const curr = stack.length ? stack[stack.length - 1] : "";
        yield curr + l;
        scopeStart.test(l) && stack.push(curr + indent);
    }
}

export const injectBody = (
    acc: string[],
    body: Nullable<string | string[] | InjectedBody>,
    key: Keys<InjectedBody> = "impl"
) => body && acc.push("", ...ensureLines(body, key), "");