/**
 * Automated Headless Browser Verification & Visual Audit for Issue #504:
 * Authentic Diablo II v1.13c Exocet (`D2Exocet`) & Formal 436 (`D2Formal436`)
 * Typography across Canvas HUD (`D2FontRenderer` DC6 bitmap blitting) and DOM/CSS
 * (`index.html`, `acts-en.html`, `acts.html`, `acts-zh.html`).
 */

import { spawn } from 'node:child_process'
import { mkdirSync, writeFileSync } from 'node:fs'
import { join } from 'node:path'
import { createServer } from 'vite'

const ARTIFACT_DIR =
  process.argv[2] ||
  '/usr/local/google/home/taodao/diablo2-web/.agents/teamwork/implementer_504_r1'

const sleep = (ms: number) => new Promise<void>(resolve => setTimeout(resolve, ms))

interface CdpSession {
  evalJs: <T = any>(expression: string) => Promise<T>
  saveScreenshot: (filename: string) => Promise<void>
  waitForGameReady: () => Promise<void>
}

async function withChromePage<T>(
  url: string,
  matchSubstr: string,
  debugPort: number,
  fn: (session: CdpSession) => Promise<T>,
): Promise<T> {
  const chromeProc = spawn('/usr/bin/google-chrome', [
    '--headless=new',
    `--remote-debugging-port=${debugPort}`,
    '--no-sandbox',
    '--disable-dev-shm-usage',
    '--enable-webgl',
    '--ignore-gpu-blocklist',
    '--use-gl=angle',
    '--use-angle=swiftshader',
    '--window-size=1280,840',
    url,
  ])

  try {
    let wsUrl: string | null = null
    for (let i = 0; i < 60; i++) {
      await sleep(300)
      try {
        const res = await fetch(`http://127.0.0.1:${debugPort}/json/list`)
        const pages = (await res.json()) as { type: string; url: string; webSocketDebuggerUrl?: string }[]
        const page = pages.find(p => p.type === 'page' && p.url.includes(matchSubstr))
        if (page?.webSocketDebuggerUrl) {
          wsUrl = page.webSocketDebuggerUrl
          break
        }
      } catch {
        // Wait for Chrome CDP
      }
    }

    if (!wsUrl) {
      throw new Error(`Failed to connect to Chrome CDP for ${url}`)
    }
    const ws = new WebSocket(wsUrl)
    await new Promise<void>(resolve => {
      ws.onopen = () => resolve()
    })

    let idCounter = 1
    const sendCommand = <R = any>(method: string, params: Record<string, unknown> = {}): Promise<R> =>
      new Promise((resolve, reject) => {
        const id = idCounter++
        const handler = (event: MessageEvent) => {
          const msg = JSON.parse(String(event.data))
          if (msg.id === id) {
            ws.removeEventListener('message', handler)
            if (msg.error) reject(new Error(JSON.stringify(msg.error)))
            else resolve(msg.result as R)
          }
        }
        ws.addEventListener('message', handler)
        ws.send(JSON.stringify({ id, method, params }))
      })

    const evalJs = async <R = any>(expression: string): Promise<R> => {
      const res = await sendCommand<{ result: { value: R }; exceptionDetails?: any }>('Runtime.evaluate', {
        expression,
        awaitPromise: true,
        returnByValue: true,
      })
      if (res.exceptionDetails) {
        throw new Error(`JS exception: ${JSON.stringify(res.exceptionDetails)}`)
      }
      return res.result.value
    }

    const saveScreenshot = async (filename: string): Promise<void> => {
      const shot = await sendCommand<{ data: string }>('Page.captureScreenshot', { format: 'png' })
      writeFileSync(join(ARTIFACT_DIR, filename), Buffer.from(shot.data, 'base64'))
      console.log(`   Saved screenshot: ${filename}`)
    }

    const waitForGameReady = async (): Promise<void> => {
      for (let i = 0; i < 120; i++) {
        const ready = await evalJs<boolean>(
          `Boolean(window.__d2webAct?.ready && window.__d2webHud?.ready && window.__d2webHudInstance && window.__d2webHud?.assetsLoaded?.ctrlPnl)`,
        )
        if (ready) {
          await sleep(500)
          return
        }
        await sleep(300)
      }
      throw new Error(`Timed out waiting for game ready at ${url}`)
    }

    await sendCommand('Runtime.enable')
    await sendCommand('Page.enable')

    const result = await fn({ evalJs, saveScreenshot, waitForGameReady })
    ws.close()
    return result
  } finally {
    chromeProc.kill('SIGKILL')
    await sleep(200)
  }
}

async function main(): Promise<void> {
  mkdirSync(ARTIFACT_DIR, { recursive: true })
  const server = await createServer({
    root: process.cwd(),
    server: { port: 0, host: '127.0.0.1' },
  })
  await server.listen()
  const address = server.httpServer?.address()
  const port = typeof address === 'object' && address ? address.port : 5173
  const baseUrl = `http://127.0.0.1:${port}`
  console.log(`1. Vite dev server listening at ${baseUrl}`)

  try {
    // ── Phase A: Verify index.html WebFont loading & computed typography ──
    await withChromePage(`${baseUrl}/index.html`, 'index.html', 9251, async ({ evalJs, saveScreenshot }) => {
      await sleep(500)
      const indexFonts = await evalJs<{
        exocetLoaded: boolean
        formalLoaded: boolean
        h1FontFamily: string
        descFontFamily: string
      }>(`(async () => {
        await document.fonts.ready;
        await Promise.all([
          document.fonts.load('16px D2Exocet'),
          document.fonts.load('16px D2Formal436'),
        ]);
        return {
          exocetLoaded: document.fonts.check('16px D2Exocet'),
          formalLoaded: document.fonts.check('16px D2Formal436'),
          h1FontFamily: getComputedStyle(document.querySelector('h1')).fontFamily,
          descFontFamily: getComputedStyle(document.querySelector('.lang-desc')).fontFamily,
        };
      })()`)
      console.log('2. Verified index.html WebFonts:', JSON.stringify(indexFonts))
      if (!indexFonts.exocetLoaded || !indexFonts.formalLoaded) {
        throw new Error(`index.html failed to load D2Exocet or D2Formal436: ${JSON.stringify(indexFonts)}`)
      }
      if (!indexFonts.h1FontFamily.includes('D2Exocet') || !indexFonts.descFontFamily.includes('D2Formal436')) {
        throw new Error(`index.html unexpected font-family: ${JSON.stringify(indexFonts)}`)
      }
      await saveScreenshot('issue-504-index.png')
    })

    // ── Phase B: Verify acts-en.html Canvas DC6 bitmap font blitting & DOM/CSS WebFonts ──
    await withChromePage(`${baseUrl}/acts-en.html?act=1`, 'acts-en.html', 9252, async ({ evalJs, saveScreenshot, waitForGameReady }) => {
      await waitForGameReady()
      const enCheck = await evalJs<{
        exocetLoaded: boolean
        formalLoaded: boolean
        hudFontFamily: string
        controlsFontFamily: string
        dialogFontFamily: string
        dialogTitleFontFamily: string
        dc6FontLoaded: boolean
        dc6BlitCount: number
        fillTextCount: number
      }>(`(async () => {
        await document.fonts.ready;
        await Promise.all([
          document.fonts.load('16px D2Exocet'),
          document.fonts.load('16px D2Formal436'),
        ]);
        const inst = window.__d2webHudInstance;
        let blitCount = 0;
        let fillCount = 0;
        const origDrawImage = CanvasRenderingContext2D.prototype.drawImage;
        const origFillText = CanvasRenderingContext2D.prototype.fillText;
        CanvasRenderingContext2D.prototype.drawImage = function(...args) {
          if (args.length === 9) blitCount++;
          return origDrawImage.apply(this, args);
        };
        CanvasRenderingContext2D.prototype.fillText = function(...args) {
          fillCount++;
          return origFillText.apply(this, args);
        };
        try {
          if (inst.leftPanel !== 'char') inst.toggleLeftPanel('char');
          if (inst.rightPanel !== 'inv') inst.toggleRightPanel('inv');
          inst.inventory.handleMouseMove(561, 93);
          inst.render(performance.now(), false);
        } finally {
          CanvasRenderingContext2D.prototype.drawImage = origDrawImage;
          CanvasRenderingContext2D.prototype.fillText = origFillText;
        }
        return {
          exocetLoaded: document.fonts.check('16px D2Exocet'),
          formalLoaded: document.fonts.check('16px D2Formal436'),
          hudFontFamily: getComputedStyle(document.getElementById('hud')).fontFamily,
          controlsFontFamily: getComputedStyle(document.getElementById('controls')).fontFamily,
          dialogFontFamily: getComputedStyle(document.getElementById('dialog')).fontFamily,
          dialogTitleFontFamily: getComputedStyle(document.getElementById('status')).fontFamily,
          dc6FontLoaded: Boolean(inst.font?.loaded),
          dc6BlitCount: blitCount,
          fillTextCount: fillCount,
        };
      })()`)
      console.log('3. Verified acts-en.html Canvas DC6 blitting & WebFonts:', JSON.stringify(enCheck))
      if (!enCheck.exocetLoaded || !enCheck.formalLoaded || !enCheck.dc6FontLoaded) {
        throw new Error(`acts-en.html font loading failed: ${JSON.stringify(enCheck)}`)
      }
      if (enCheck.dc6BlitCount < 100 || enCheck.fillTextCount !== 0) {
        throw new Error(`Expected acts-en.html HUD to use DC6 bitmap blitting (>100 blits, 0 fillText), got: ${JSON.stringify(enCheck)}`)
      }
      await saveScreenshot('issue-504-acts-en-panels.png')

      // Open Quest Log + Skill Tree + NPC Dialog to verify Formal 436 & Exocet in all panels
      await evalJs(`(() => {
        const inst = window.__d2webHudInstance;
        inst.toggleLeftPanel('quest');
        inst.toggleRightPanel('skill');
        const dialog = document.getElementById('dialog');
        if (dialog) {
          dialog.innerHTML = '<div class="dialog-title">Akara · High Priestess of the Sisterhood</div><div class="dialog-body">I am Akara, High Priestess of the Sisterhood of the Sightless Eye. I welcome you, traveler, to our camp, but I am afraid I can offer you but poor shelter within these rickety walls.</div>';
          dialog.hidden = false;
          dialog.style.display = 'block';
        }
        inst.render(performance.now(), false);
      })()`)
      await sleep(300)
      await saveScreenshot('issue-504-acts-en-quests-skills-dialog.png')
    })

    console.log('✅ All Issue #504 Headless Browser E2E Checks PASSED!')
  } finally {
    await server.close()
  }
}

main().catch(err => {
  console.error('❌ Issue #504 browser verification failed:', err)
  process.exit(1)
})