/**
 * Client half of dsh-better-sidebar: resolves the user's "Side card"
 * preferences through the plugin's own fenced settings route, mounts the
 * right sidebar portal (inside an error boundary so a rendering failure
 * shows an error strip instead of a blank panel), registers the turn-tail
 * interception, and contributes the Side card settings section to the DSH
 * Settings shell. Requires the runtime's slots and sessions services; the
 * bundle itself is a module-table consumer only (react + ui-primitives +
 * xterm, all provided or inlined).
 */
import { Component, createElement, type ErrorInfo, type ReactNode } from 'react'
import { createRoot, type Root } from 'react-dom/client'
import type { Context } from '../context-types.ts'
import { createSidebarStore } from './state.ts'
import { Sidebar } from './Sidebar.tsx'
import { registerTurnTailInterception } from './intercept.tsx'
import { loadPrefs } from './prefs.ts'
import { SideCardSection } from './SideCardSection.tsx'
import { api } from './api.ts'
import { t } from './locales.ts'
import css from './sidebar.module.css'
import './layout.css'

/** Services required before mounting (provided by the client runtime). */
export const inject = ['slots', 'sessions', 'connection']

/**
 * Error boundary over the sidebar tree: a render error must never blank the
 * whole panel silently — it shows a dismissible error strip and logs the
 * stack for diagnosis.
 */
class SidebarBoundary extends Component<{ children: ReactNode }, { error: string | null }> {
  state = { error: null as string | null }

  static getDerivedStateFromError(error: unknown): { error: string } {
    return { error: error instanceof Error ? error.message : String(error) }
  }

  componentDidCatch(error: Error, info: ErrorInfo): void {
    console.error('[dsh-better-sidebar] render error:', error, info.componentStack)
  }

  render(): ReactNode {
    if (this.state.error !== null) {
      return (
        <div className={css.boundaryError}>
          <span>dsh-better-sidebar: {this.state.error}</span>
          <button
            type="button"
            className={css.terminalRetry}
            onClick={() => { this.setState({ error: null }) }}
          >
            {t('terminalRetry')}
          </button>
        </div>
      )
    }
    return this.props.children
  }
}

/**
 * Client plugin body.
 * @param ctx - the client cordis context (slots, sessions).
 */
export function apply(ctx: Context): void {
  // One store instance per activation: production code creates it only here,
  // then hands it to the mounted panel and closes over it in the slot
  // registrations (the official createXXXStore() factory rule — no
  // module-level singleton).
  const sidebarStore = createSidebarStore()
  // A failure anywhere in the client lifecycle must never take the app down
  // silently: log with the plugin prefix and pin a visible diagnostic strip
  // to the page so a blank panel is never the only symptom.
  const fail = (phase: string, error: unknown): void => {
    console.error(`[dsh-better-sidebar] ${phase} error:`, error)
    try {
      const bar = document.createElement('div')
      bar.style.cssText = 'position:fixed;left:8px;bottom:8px;z-index:2147483000;max-width:70vw;padding:8px 12px;'
        + 'font:12px/1.5 ui-monospace,SFMono-Regular,Menlo,monospace;color:#f2a1a1;background:#1b1b22;'
        + 'border:1px solid #f2a1a1;border-radius:8px;white-space:pre-wrap'
      bar.textContent = `[dsh-better-sidebar] ${phase} error: ${error instanceof Error ? error.message : String(error)}`
      document.body.appendChild(bar)
    } catch {
      // Nothing left to report with.
    }
  }
  try {
    ctx.effect(() => {
      let disposed = false
      let root: Root | undefined
      let host: HTMLDivElement | undefined
      void (async () => {
        // Resolve the user's side card prefs BEFORE the first session seeds,
        // so a brand-new conversation opens (or stays closed) at the chosen
        // width from first paint. A settings route failure falls back to the
        // schema defaults; the sidebar still mounts (a stalled wire gives up
        // after the timeout and mounts on the defaults).
        const prefs = await Promise.race([
          loadPrefs(api),
          new Promise<null>(resolve => { const timer = window.setTimeout(() => resolve(null), 2000) }),
        ])
        if (prefs !== null) sidebarStore.setPrefs(prefs)
        if (disposed) return
        try {
          host = document.createElement('div')
          host.setAttribute('data-dsh-better-sidebar', '')
          document.body.appendChild(host)
          root = createRoot(host)
          root.render(createElement(SidebarBoundary, null, createElement(Sidebar, { ctx, store: sidebarStore })))
        } catch (error) {
          fail('mount', error)
        }
      })()
      return () => {
        disposed = true
        root?.unmount()
        host?.remove()
      }
    }, 'dsh-better-sidebar: sidebar mount')

    ctx.effect(
      () => {
        try {
          return registerTurnTailInterception(ctx, sidebarStore)
        } catch (error) {
          fail('interception', error)
          return undefined
        }
      },
      'dsh-better-sidebar: turn-tail interception',
    )

    // The "Side card" settings section: appears in the DSH Settings shell
    // once the shell's declaration is on the ledger (slots.inject waits for
    // it); the section reads/writes the prefs through the plugin's own
    // fenced settings route and keeps the shared store in sync.
    ctx.slots.inject('settings.section', () => ctx.slots.register({
      name: 'settings.section',
      id: 'better-sidebar',
      order: 100,
      label: () => t('settingsNav'),
      inject: () => ({ store: sidebarStore }),
    }, SideCardSection))
  } catch (error) {
    fail('load', error)
  }
}