import { getSystemConfig } from '@/lib/config'
import { getChatProvider } from '@/lib/ai/factory'

export interface ClipAnalysis {
  title: string
  summary: string
  tags: string[]
  readingTimeMinutes: number
}

function parseAnalysisJson(raw: string): ClipAnalysis | null {
  const trimmed = raw.trim()
  const jsonMatch = trimmed.match(/\{[\s\S]*\}/)
  if (!jsonMatch) return null
  try {
    const parsed = JSON.parse(jsonMatch[0]) as Partial<ClipAnalysis>
    const tags = Array.isArray(parsed.tags)
      ? parsed.tags.filter((t): t is string => typeof t === 'string').slice(0, 5)
      : []
    const readingTime = typeof parsed.readingTimeMinutes === 'number'
      ? Math.max(1, Math.min(120, Math.round(parsed.readingTimeMinutes)))
      : 5
    return {
      title: typeof parsed.title === 'string' && parsed.title.trim() ? parsed.title.trim().slice(0, 200) : 'Web clip',
      summary: typeof parsed.summary === 'string' ? parsed.summary.trim().slice(0, 800) : '',
      tags,
      readingTimeMinutes: readingTime,
    }
  } catch {
    return null
  }
}

function estimateReadingMinutes(text: string): number {
  const words = text.split(/\s+/).filter(Boolean).length
  return Math.max(1, Math.round(words / 200))
}

export async function analyzeClipContent(params: {
  url: string
  title: string
  textContent: string
}): Promise<ClipAnalysis> {
  const excerpt = params.textContent.slice(0, 6000)
  const fallbackReading = estimateReadingMinutes(params.textContent)

  try {
    const config = await getSystemConfig()
    const provider = getChatProvider(config)
    const prompt = `You analyze web articles for a personal knowledge base. URL: ${params.url}
Page title: ${params.title}

Content excerpt:
${excerpt}

Respond with ONLY valid JSON (no markdown):
{
  "title": "concise improved title",
  "summary": "max 3 sentences in the same language as the content",
  "tags": ["tag1", "tag2"],
  "readingTimeMinutes": ${fallbackReading}
}

Rules: tags max 5, short lowercase labels, summary factual.`

    const raw = await provider.generateText(prompt)
    const parsed = parseAnalysisJson(raw)
    if (parsed) {
      if (!parsed.title) parsed.title = params.title || 'Web clip'
      if (!parsed.summary && params.textContent) {
        parsed.summary = params.textContent.slice(0, 400)
      }
      if (parsed.tags.length === 0) parsed.tags = []
      return parsed
    }
  } catch (error) {
    console.error('[ClipAnalyze] AI failed:', error)
  }

  return {
    title: params.title || 'Web clip',
    summary: params.textContent.slice(0, 400),
    tags: [],
    readingTimeMinutes: fallbackReading,
  }
}