import { useEffect, useState } from 'react'
import { useParams, useSearchParams } from 'react-router-dom'
import { Sparkles, Loader2 } from 'lucide-react'
import { useFlowPilotSession } from '@/hooks/useFlowPilotSession'
import { FlowPilotIntake, FlowPilotSession, SessionBriefing } from '@/components/flowpilot'
import { aiSessionsApi } from '@/api'
import { toast } from '@/lib/toast'

export default function FlowPilotSessionPage() {
  const { sessionId } = useParams<{ sessionId?: string }>()
  const [searchParams, setSearchParams] = useSearchParams()
  const isPickup = searchParams.get('pickup') === 'true'
  const fp = useFlowPilotSession()
  const [pickingUp, setPickingUp] = useState(false)

  // Load existing session if ID in URL
  useEffect(() => {
    if (sessionId && !fp.session) {
      fp.loadSession(sessionId)
    }
  }, [sessionId]) // eslint-disable-line react-hooks/exhaustive-deps

  const handlePickupContinue = async () => {
    if (!sessionId) return
    setPickingUp(true)
    try {
      await aiSessionsApi.pickupSession(sessionId, { resume_mode: 'continue' })
      // Clear pickup param and reload the session as active
      setSearchParams({})
      await fp.loadSession(sessionId)
    } catch (e: unknown) {
      const message = e instanceof Error ? e.message : 'Failed to pick up session'
      toast.error(message)
    } finally {
      setPickingUp(false)
    }
  }

  const handlePickupFresh = async (context: string) => {
    if (!sessionId) return
    setPickingUp(true)
    try {
      await aiSessionsApi.pickupSession(sessionId, {
        resume_mode: 'fresh',
        additional_context: context,
      })
      setSearchParams({})
      await fp.loadSession(sessionId)
    } catch (e: unknown) {
      const message = e instanceof Error ? e.message : 'Failed to pick up session'
      toast.error(message)
    } finally {
      setPickingUp(false)
    }
  }

  // Error state
  if (fp.error && !fp.session) {
    return (
      <div className="flex items-center justify-center min-h-[50vh]">
        <div className="glass-card-static p-6 text-center max-w-md">
          <p className="text-sm text-rose-400">{fp.error}</p>
          <button
            onClick={() => window.location.reload()}
            className="mt-3 text-xs text-muted-foreground hover:text-foreground transition-colors"
          >
            Try again
          </button>
        </div>
      </div>
    )
  }

  // Loading
  if (fp.isLoading && !fp.session) {
    return (
      <div className="flex items-center justify-center min-h-[50vh]">
        <Loader2 size={24} className="animate-spin text-muted-foreground" />
      </div>
    )
  }

  // Intake screen (no session yet)
  if (!fp.session) {
    return (
      <div className="h-full p-6">
        <FlowPilotIntake onSubmit={fp.startSession} isLoading={fp.isLoading} />
      </div>
    )
  }

  // Escalation pickup briefing
  if (isPickup && fp.session.status === 'requesting_escalation' && fp.session.escalation_reason) {
    // Build escalation package from session detail
    // The escalation_package is in the session but not directly on AISessionDetail —
    // we use what's available from the session fields
    const escalationPackage = {
      problem_summary: fp.session.problem_summary ?? undefined,
      escalation_reason: fp.session.escalation_reason ?? undefined,
      // Steps are available from the session detail
      steps_tried: fp.allSteps.map(step => ({
        step_type: step.step_type,
        description: (step.content as Record<string, string>)?.text || '',
      })),
    }

    return (
      <div className="flex h-full flex-col">
        {/* Header */}
        <div
          className="flex items-center gap-3 border-b px-5 py-3 shrink-0"
          style={{ borderColor: 'var(--glass-border)' }}
        >
          <span className="flex h-7 w-7 items-center justify-center rounded-lg bg-amber-500/10">
            <Sparkles size={14} className="text-amber-400" />
          </span>
          <div className="flex-1 min-w-0">
            <h1 className="font-heading text-sm font-semibold text-foreground truncate">
              Escalation Pickup — {fp.session.problem_summary || 'FlowPilot Session'}
            </h1>
          </div>
          <span className="font-label rounded-md bg-amber-500/10 px-2 py-0.5 text-[0.625rem] uppercase tracking-wider text-amber-400 border border-amber-500/20">
            Awaiting pickup
          </span>
        </div>

        {/* Briefing */}
        <div className="flex-1 overflow-y-auto p-6">
          <div className="mx-auto max-w-2xl">
            <SessionBriefing
              escalationPackage={escalationPackage}
              onContinue={handlePickupContinue}
              onFresh={handlePickupFresh}
              isProcessing={pickingUp}
            />
          </div>
        </div>
      </div>
    )
  }

  // Active/completed session
  return (
    <div className="flex h-full flex-col">
      {/* Header */}
      <div
        className="flex items-center gap-3 border-b px-5 py-3 shrink-0"
        style={{ borderColor: 'var(--glass-border)' }}
      >
        <span className="flex h-7 w-7 items-center justify-center rounded-lg bg-primary/10">
          <Sparkles size={14} className="text-primary" />
        </span>
        <div className="flex-1 min-w-0">
          <h1 className="font-heading text-sm font-semibold text-foreground truncate">
            {fp.session.problem_summary || 'FlowPilot Session'}
          </h1>
        </div>
        <span className="font-label rounded-md bg-card px-2 py-0.5 text-[0.625rem] uppercase tracking-wider text-muted-foreground border border-border">
          {fp.session.status}
        </span>
      </div>

      {/* Session content */}
      <div className="flex-1 min-h-0">
        <FlowPilotSession
          session={fp.session}
          allSteps={fp.allSteps}
          currentStep={fp.currentStep}
          isProcessing={fp.isProcessing}
          canResolve={fp.canResolve}
          canEscalate={fp.canEscalate}
          documentation={fp.documentation}
          psaPushStatus={fp.psaPushStatus}
          psaPushError={fp.psaPushError}
          memberMappingWarning={fp.memberMappingWarning}
          onRespond={fp.respondToStep}
          onResolve={fp.resolveSession}
          onEscalate={fp.escalateSession}
          onPause={fp.pauseSession}
          onResume={fp.resumeOwnSession}
          onRate={fp.rateSession}
        />
      </div>
    </div>
  )
}