// `rnx describe` — format the pruned visible semantic tree.

import { maybeHint } from '../../hints'
import { inspectDescribe, type DescribeDumpOptions } from './core'
import {
  maybeWaitForStartedScreenTransitions,
  printJson,
  sleep,
  wantsJson,
} from './shared'
import type { WsBridge } from '../../ws-bridge'

export interface DescribeOptions {
  bridge: WsBridge
  args: string[]
  positional: string[]
}

function flagValue(args: string[], name: string): string | null {
  const i = args.indexOf(name)
  return i >= 0 && i + 1 < args.length ? args[i + 1] : null
}

export async function runDescribeSubcommand(opts: DescribeOptions): Promise<void> {
  const { bridge, args, positional } = opts
  const verbose = args.includes('--verbose') || args.includes('-v')
  const jsonOut = wantsJson(args)
  const verboseDescribeTransitions = verbose && !jsonOut
  const watch = args.includes('--watch') || args.includes('-w')
  const watchInterval = 1000
  const compact = args.includes('--compact')
  const hideXy = args.includes('--no-xy')
  const testIdLike = flagValue(args, '--testid-like')
  const onlyGlob = flagValue(args, '--only')
  const subtreeRoot = flagValue(args, '--subtree')

  // bare positional still works — routes to --only if it looks globby,
  // otherwise preserves the old substring-match behavior as `filter`. guard
  // against a flag-looking token leaking in as a filter: an unrecognized
  // `--flag` that the arg parser didn't strip must never become a text filter
  // (that's how `describe --compact` used to match nothing).
  const positionalFilter =
    positional[1] && !positional[1].startsWith('-') ? positional[1] : undefined
  const bareIsGlob = positionalFilter ? /[*?]/.test(positionalFilter) : false
  const filter = !bareIsGlob && !onlyGlob ? positionalFilter : undefined
  const effectiveOnlyGlob = onlyGlob ?? (bareIsGlob ? positionalFilter : undefined)

  const runOnce = async () => {
    await maybeWaitForStartedScreenTransitions(bridge, {
      verbose: verboseDescribeTransitions,
    })
    const dumpOpts: DescribeDumpOptions = {
      describe: true,
      verbose,
      filter: filter || '',
      testIdLike: testIdLike || undefined,
      onlyGlob: effectiveOnlyGlob || undefined,
      subtreeRoot: subtreeRoot || undefined,
      compact,
      hideXy,
      // no terminal to fit, so nothing gets clipped on the way out
      fullText: jsonOut,
    }
    const result = await inspectDescribe(bridge, dumpOpts)
    const tree = result?.tree

    if (jsonOut) {
      printJson({ tree: tree ?? '' })
      return
    }

    if (typeof tree === 'string' && tree.startsWith('__SUBTREE_NOT_FOUND__:')) {
      const missing = tree.slice('__SUBTREE_NOT_FOUND__:'.length)
      console.log(`  subtree root not found: ${missing}`)
      maybeHint('subtree-root-not-found', missing)
      return
    }

    if (!tree) {
      const nodeCount = result?.nodeCount ?? 0
      console.log('  no matching nodes found')
      const anyFilterActive = filter || testIdLike || effectiveOnlyGlob || subtreeRoot
      if (!anyFilterActive && nodeCount < 10) {
        maybeHint('app-still-loading', nodeCount)
      }
      return
    }

    console.log(tree)

    const anyFilterActive = filter || testIdLike || effectiveOnlyGlob || subtreeRoot
    const searchFilterActive = filter || testIdLike || effectiveOnlyGlob
    if (searchFilterActive && !watch) {
      maybeHint('describe-filter-context')
    }

    // when no filter was active and the tree got long, nudge once per
    // session toward the narrowing flags — this is exactly the case the
    // user flagged where "which row is the swap sheet" got buried under
    // 100+ lines of home content.
    if (!anyFilterActive && !watch) {
      const lineCount = tree.split('\n').length
      if (lineCount >= 80) {
        maybeHint('describe-use-filters')
      }
    }
  }

  if (watch) {
    console.log('  watching... (Ctrl+C to stop)\n')
    while (true) {
      console.clear()
      await runOnce()
      await sleep(watchInterval)
    }
  } else {
    await runOnce()
  }
}