import path from 'path'
import type { SourceFile } from './SourceFile.js'
import type { Type } from './types/Type.js'
import { getTypeAs } from './types/getTypeAs.js'
import { OptionalType } from './types/OptionalType.js'
import { ArrayType } from './types/ArrayType.js'

type Comment = '///' | '#'

export function createFileMetadataString(
  filename: string,
  comment: Comment = '///'
): string {
  return `
${comment}
${comment} ${filename}
${comment} This file was generated by nitrogen. DO NOT MODIFY THIS FILE.
${comment} https://github.com/mrousavy/nitro
${comment} Copyright © Marc Rousavy @ Margelo
${comment}
`.trim()
}

export function isFunction(type: Type): boolean {
  switch (type.kind) {
    case 'function':
      return true
    case 'optional': {
      const optional = getTypeAs(type, OptionalType)
      return isFunction(optional.wrappingType)
    }
    default:
      return false
  }
}

export function toReferenceType(type: string): `const ${typeof type}&` {
  return `const ${type}&`
}

export function escapeCppName(string: string): string {
  // Replace non-alphanumeric characters with underscores
  let escapedStr = string.replace(/[^a-zA-Z0-9_]/g, '_')

  // Ensure the first character is a letter or underscore
  if (!/^[a-zA-Z_]/.test(escapedStr)) {
    escapedStr = '_' + escapedStr
  }

  return escapedStr
}

/**
 * Get a type's "looselyness".
 * The concept is as follows:
 * - If a `type` is easy to runtime-check in JSI (e.g. a `number` is just `.isNumber()`),
 * it should have a very low looselyness value returned here.
 * - If a `type` is hard to runtime-check in JSI (e.g. `AnyMap` can have any key),
 * it should have a very high looselyness value returned here.
 * - Type's looselyness values are compared against each other to determine in which
 * order they should be runtime type-checked - e.g. `AnyMap` should be last (as it can
 * always be `true` if it's just an `object`), and `Promise` should be sooner (as it can
 * be `instanceof` checked)
 * - As a performance optimization, rank faster checks earlier (e.g. `isNumber()` before
 * `instanceof`, as `instanceof` requires global constructor lookup)
 */
function getTypeLooselyness(type: Type): number {
  switch (type.kind) {
    case 'array-buffer':
      // We have `.isArrayBuffer()`
      return 0
    case 'int64':
    case 'uint64':
      // We have `.isBigInt()`
      return 0
    case 'boolean':
      // We have `.isBool()`
      return 0
    case 'null':
      // We have `isNull()`
      return 0
    case 'number':
      // We have `isNumber()` (but it can also be an enum)
      return 1
    case 'optional':
      // We have `isUndefined()`
      return 0
    case 'function':
      // We have `.isFunction()`
      return 0
    case 'string':
      // We have `.isString()` (but it can also be a union)
      return 1
    case 'enum':
      // We have `.isNumber()` or `.isString()` and is within range, only
      // if it's not within range, it can fallback to `string` or `number`
      return 0
    case 'array':
      // We have `.isArray()` - but it should extend the item type's looselyness
      const arrayType = getTypeAs(type, ArrayType)
      return 0.5 * getTypeLooselyness(arrayType.itemType)
    case 'hybrid-object':
      // We have `getNativeState<T>()`
      return 0
    case 'hybrid-object-base':
      // We have `getNativeState<HybridObject>()`
      return 1
    case 'tuple':
      // We have `.isArray()` and `canConvert<T>()`
      return 1
    case 'date':
      // We have `instanceof Date`
      return 2
    case 'error':
      // We have `instanceof Error`
      return 2
    case 'promise':
      // We have `instanceof Promise`
      return 2
    case 'custom-type':
      // Up to the user
      return 1
    case 'record':
      // Super loose, only type counts
      return 3
    case 'map':
      // This is just super loose
      return 4
    case 'struct':
      // We check each property individually
      return 1
    case 'variant':
      // Pretty loose
      return 2
    case 'result-wrapper':
      // Not loose at all
      return 0
    case 'void':
      // Not a type
      return 0
  }
}

/**
 * Compares the "looselyness" of the types.
 * Returns a positive number if {@linkcode a} is more loose than {@linkcode b},
 * and a negative number if otherwise.
 */
export function compareLooselyness(a: Type, b: Type): number {
  return getTypeLooselyness(a) - getTypeLooselyness(b)
}

export function isNotDuplicate<T>(item: T, index: number, array: T[]): boolean {
  return array.indexOf(item) === index
}

export function isCppFile(file: SourceFile): boolean {
  return file.name.endsWith('cpp') || file.name.endsWith('c')
}

export function getRelativeDirectory(file: SourceFile): string {
  return path.join(
    '..',
    'nitrogen',
    'generated',
    file.platform,
    file.language,
    ...file.subdirectory,
    file.name
  )
}

export function getRelativeDirectoryGenerated(...subpath: string[]): string {
  return path.join('..', 'nitrogen', 'generated', ...subpath)
}