import { startsWith } from '../../tools/utils'
import type { StackTrace, StackFrame } from './types'

const UNKNOWN_FUNCTION = '?'

/**
 * Computes a stack trace for an exception.
 */
export function computeStackTrace(ex: unknown): StackTrace {
  const stack: StackFrame[] = []

  let stackProperty = tryToGetString(ex, 'stack')
  const exString = String(ex)
  if (stackProperty && startsWith(stackProperty, exString)) {
    stackProperty = stackProperty.slice(exString.length)
  }
  if (stackProperty) {
    stackProperty.split('\n').forEach((line) => {
      const stackFrame =
        parseChromeLine(line) || parseChromeAnonymousLine(line) || parseWinLine(line) || parseGeckoLine(line)
      if (stackFrame) {
        if (!stackFrame.func && stackFrame.line) {
          stackFrame.func = UNKNOWN_FUNCTION
        }

        stack.push(stackFrame)
      }
    })
  }

  return {
    message: tryToGetString(ex, 'message'),
    name: tryToGetString(ex, 'name'),
    stack,
  }
}
const fileUrl = '((?:file|https?|blob|chrome-extension|native|eval|webpack|<anonymous>|\\w+\\.|\\/).*?)'
const filePosition = '(?::(\\d+))'
const CHROME_LINE_RE = new RegExp(`^\\s*at (.*?) ?\\(${fileUrl}${filePosition}?${filePosition}?\\)?\\s*$`, 'i')

const CHROME_EVAL_RE = new RegExp(`\\((\\S*)${filePosition}${filePosition}\\)`)

function parseChromeLine(line: string): StackFrame | undefined {
  const parts = CHROME_LINE_RE.exec(line)

  if (!parts) {
    return
  }

  const isNative = parts[2] && parts[2].indexOf('native') === 0 // start of line
  const isEval = parts[2] && parts[2].indexOf('eval') === 0 // start of line
  const submatch = CHROME_EVAL_RE.exec(parts[2])

  if (isEval && submatch) {
    // throw out eval line/column and use top-most line/column number
    parts[2] = submatch[1] // url
    parts[3] = submatch[2] // line
    parts[4] = submatch[3] // column
  }

  return {
    args: isNative ? [parts[2]] : [],
    column: parts[4] ? +parts[4] : undefined,
    func: parts[1] || UNKNOWN_FUNCTION,
    line: parts[3] ? +parts[3] : undefined,
    url: !isNative ? parts[2] : undefined,
  }
}

const CHROME_ANONYMOUS_FUNCTION_RE = new RegExp(`^\\s*at ?${fileUrl}${filePosition}?${filePosition}??\\s*$`, 'i')

function parseChromeAnonymousLine(line: string): StackFrame | undefined {
  const parts = CHROME_ANONYMOUS_FUNCTION_RE.exec(line)

  if (!parts) {
    return
  }

  return {
    args: [],
    column: parts[3] ? +parts[3] : undefined,
    func: UNKNOWN_FUNCTION,
    line: parts[2] ? +parts[2] : undefined,
    url: parts[1],
  }
}

const WINJS_LINE_RE =
  /^\s*at (?:((?:\[object object\])?.+) )?\(?((?:file|ms-appx|https?|webpack|blob):.*?):(\d+)(?::(\d+))?\)?\s*$/i

function parseWinLine(line: string): StackFrame | undefined {
  const parts = WINJS_LINE_RE.exec(line)
  if (!parts) {
    return
  }

  return {
    args: [],
    column: parts[4] ? +parts[4] : undefined,
    func: parts[1] || UNKNOWN_FUNCTION,
    line: +parts[3],
    url: parts[2],
  }
}

const GECKO_LINE_RE =
  /^\s*(.*?)(?:\((.*?)\))?(?:^|@)((?:file|https?|blob|chrome|webpack|resource|capacitor|\[native).*?|[^@]*bundle)(?::(\d+))?(?::(\d+))?\s*$/i
const GECKO_EVAL_RE = /(\S+) line (\d+)(?: > eval line \d+)* > eval/i

function parseGeckoLine(line: string): StackFrame | undefined {
  const parts = GECKO_LINE_RE.exec(line)
  if (!parts) {
    return
  }

  const isEval = parts[3] && parts[3].indexOf(' > eval') > -1
  const submatch = GECKO_EVAL_RE.exec(parts[3])

  if (isEval && submatch) {
    // throw out eval line/column and use top-most line number
    parts[3] = submatch[1]
    parts[4] = submatch[2]
    parts[5] = undefined! // no column when eval
  }

  return {
    args: parts[2] ? parts[2].split(',') : [],
    column: parts[5] ? +parts[5] : undefined,
    func: parts[1] || UNKNOWN_FUNCTION,
    line: parts[4] ? +parts[4] : undefined,
    url: parts[3],
  }
}

function tryToGetString(candidate: unknown, property: string) {
  if (typeof candidate !== 'object' || !candidate || !(property in candidate)) {
    return undefined
  }
  const value = (candidate as { [k: string]: unknown })[property]
  return typeof value === 'string' ? value : undefined
}