import Link from 'next/link';
import {
  ArrowRight,
  Award,
  Calendar,
  Code,
  FileText,
  PenTool,
  Sparkles,
  Bot,
} from 'lucide-react';
import { Card, CardBody, CardHeader, Badge, Avatar, Button } from '@nextcraft/ui';
import {
  primaryLearner,
  competencyStacks,
  allCompetencies,
  learnerArtifacts,
  upcomingDefenses,
  learnerMicrocredentials,
} from '@nextcraft/mock-data';
import { AiTutorChat } from '../../../components/learner/ai-tutor-chat';
import { ProgressGraph } from '../../../components/learner/progress-graph';

const ACTIVE_COMPETENCY_IDS = [
  'stack-orchestration-c003',
  'stack-orchestration-c008',
  'stack-safety-c019',
  'stack-safety-c023',
];

const ACTIVE_PROGRESS: Record<string, number> = {
  'stack-orchestration-c003': 45,
  'stack-orchestration-c008': 38,
  'stack-safety-c019': 52,
  'stack-safety-c023': 30,
};

const ARTIFACT_ICON = {
  code: Code,
  design: PenTool,
  simulation: Sparkles,
  document: FileText,
} as const;

function formatDate(iso: string): string {
  const d = new Date(iso);
  return d.toLocaleDateString('en-US', { month: 'short', day: 'numeric' });
}

export default function DashboardPage() {
  const learner = primaryLearner;
  const activeStack = competencyStacks.find((s) => s.id === 'stack-orchestration')!;
  const activeCompetencies = ACTIVE_COMPETENCY_IDS
    .map((id) => allCompetencies.find((c) => c.id === id))
    .filter((c): c is NonNullable<typeof c> => Boolean(c));

  const stackProgress = learner.progress[activeStack.id] ?? 0;
  const masteredInStack = activeStack.competencies.filter((c) => c.status === 'mastered').length;
  const totalInStack = activeStack.competencies.length;

  const milestones = Array.from({ length: totalInStack }, (_, i) => i < masteredInStack);

  return (
    <div className="flex flex-col gap-6">
      {/* Header */}
      <header className="flex items-center gap-4">
        <Avatar name={learner.name} src={learner.avatar} size="lg" />
        <div>
          <h1 className="text-2xl font-bold tracking-tight text-slate-900 dark:text-slate-100">
            Welcome back, {learner.name.split(' ')[0]}
          </h1>
          <p className="text-sm text-slate-500 dark:text-slate-400">
            You&apos;re {stackProgress}% through the {activeStack.name} stack.
          </p>
        </div>
      </header>

      {/* Top row: active competencies + milestone tracker */}
      <div className="grid grid-cols-1 gap-4 lg:grid-cols-3">
        {/* Active competencies (spans 2) */}
        <Card className="lg:col-span-2">
          <CardHeader>
            <h2 className="text-base font-semibold text-slate-900 dark:text-slate-100">
              Active competencies
            </h2>
            <p className="text-sm text-slate-500 dark:text-slate-400">
              {activeStack.name}
            </p>
          </CardHeader>
          <CardBody className="flex flex-col gap-4">
            {activeCompetencies.map((c) => {
              const pct = ACTIVE_PROGRESS[c.id] ?? 0;
              return (
                <div key={c.id} className="flex flex-col gap-2">
                  <div className="flex items-center justify-between">
                    <Link
                      href={`/learn/${c.id}`}
                      className="text-sm font-medium text-slate-800 hover:text-primary-700 dark:text-slate-100 dark:hover:text-primary-300"
                    >
                      {c.name}
                    </Link>
                    <span className="text-xs text-slate-500 dark:text-slate-400">{pct}%</span>
                  </div>
                  <div className="h-2 overflow-hidden rounded-full bg-slate-100 dark:bg-slate-800">
                    <div
                      className="h-full rounded-full bg-amber-500"
                      style={{ width: `${pct}%` }}
                    />
                  </div>
                </div>
              );
            })}
          </CardBody>
        </Card>

        {/* Milestone tracker */}
        <Card>
          <CardHeader>
            <h2 className="text-base font-semibold text-slate-900 dark:text-slate-100">
              Milestone tracker
            </h2>
            <p className="text-sm text-slate-500 dark:text-slate-400">
              {masteredInStack}/{totalInStack} competencies mastered
            </p>
          </CardHeader>
          <CardBody>
            <ol className="flex flex-wrap gap-2">
              {milestones.map((done, i) => (
                <li
                  key={i}
                  className={`flex h-7 w-7 items-center justify-center rounded-full text-xs font-medium ${
                    done
                      ? 'bg-emerald-100 text-emerald-700 dark:bg-emerald-900/40 dark:text-emerald-300'
                      : 'bg-slate-100 text-slate-400 dark:bg-slate-800 dark:text-slate-500'
                  }`}
                  title={done ? 'Mastered' : 'Not yet mastered'}
                >
                  {done ? <Award className="h-3.5 w-3.5" /> : i + 1}
                </li>
              ))}
            </ol>
            <div className="mt-4">
              <div className="h-2 overflow-hidden rounded-full bg-slate-100 dark:bg-slate-800">
                <div
                  className="h-full rounded-full bg-accent-500"
                  style={{ width: `${stackProgress}%` }}
                />
              </div>
              <p className="mt-1 text-xs text-slate-500 dark:text-slate-400">
                {stackProgress}% overall stack progress
              </p>
            </div>
          </CardBody>
        </Card>
      </div>

      {/* Progress graph (full width) */}
      <Card>
        <CardHeader>
          <h2 className="text-base font-semibold text-slate-900 dark:text-slate-100">
            Mastery progress
          </h2>
          <p className="text-sm text-slate-500 dark:text-slate-400">
            Last 8 weeks · AI Orchestration stack
          </p>
        </CardHeader>
        <CardBody>
          <ProgressGraph />
        </CardBody>
      </Card>

      {/* Bottom row: recent artifacts + upcoming defenses */}
      <div className="grid grid-cols-1 gap-4 lg:grid-cols-2">
        {/* Recent artifacts */}
        <Card>
          <CardHeader>
            <h2 className="text-base font-semibold text-slate-900 dark:text-slate-100">
              Recent artifacts
            </h2>
            <p className="text-sm text-slate-500 dark:text-slate-400">
              {learnerArtifacts.length} submitted
            </p>
          </CardHeader>
          <CardBody className="flex flex-col gap-3">
            {learnerArtifacts.slice(0, 4).map((a) => {
              const Icon = ARTIFACT_ICON[a.type] ?? FileText;
              return (
                <div
                  key={a.id}
                  className="flex items-start gap-3 rounded-md border border-slate-200 p-3 dark:border-slate-800"
                >
                  <span className="mt-0.5 flex h-8 w-8 shrink-0 items-center justify-center rounded-md bg-primary-100 text-primary-700 dark:bg-primary-900/40 dark:text-primary-300">
                    <Icon className="h-4 w-4" />
                  </span>
                  <div className="flex-1">
                    <div className="flex items-center justify-between gap-2">
                      <p className="text-sm font-medium text-slate-900 dark:text-slate-100">
                        {a.name}
                      </p>
                      <span className="text-xs text-slate-400">{formatDate(a.createdAt)}</span>
                    </div>
                    <p className="mt-0.5 text-xs text-slate-500 dark:text-slate-400">
                      {a.type}
                    </p>
                  </div>
                </div>
              );
            })}
          </CardBody>
        </Card>

        {/* Upcoming defenses */}
        <Card>
          <CardHeader>
            <h2 className="text-base font-semibold text-slate-900 dark:text-slate-100">
              Upcoming defenses
            </h2>
            <p className="text-sm text-slate-500 dark:text-slate-400">
              Oral exams on the calendar
            </p>
          </CardHeader>
          <CardBody className="flex flex-col gap-3">
            {upcomingDefenses.map((d) => {
              const comp = allCompetencies.find((c) => c.id === d.competencyId);
              if (!comp) return null;
              return (
                <div
                  key={d.id}
                  className="flex items-center justify-between gap-3 rounded-md border border-slate-200 p-3 dark:border-slate-800"
                >
                  <div className="flex items-start gap-3">
                    <span className="mt-0.5 flex h-8 w-8 shrink-0 items-center justify-center rounded-md bg-amber-100 text-amber-700 dark:bg-amber-900/40 dark:text-amber-300">
                      <Calendar className="h-4 w-4" />
                    </span>
                    <div>
                      <p className="text-sm font-medium text-slate-900 dark:text-slate-100">
                        {comp.name}
                      </p>
                      <p className="text-xs text-slate-500 dark:text-slate-400">
                        {d.status === 'scheduled' ? 'Scheduled' : 'Pending scheduling'}
                      </p>
                    </div>
                  </div>
                  <Link href={`/defend/${comp.id}`}>
                    <Button size="sm" variant="outline">
                      Prepare
                    </Button>
                  </Link>
                </div>
              );
            })}
          </CardBody>
        </Card>
      </div>

      {/* AI Tutor chat */}
      <Card>
        <CardHeader>
          <div className="flex items-center gap-2">
            <span className="flex h-8 w-8 items-center justify-center rounded-full bg-primary-100 text-primary-700 dark:bg-primary-900/40 dark:text-primary-300">
              <Bot className="h-4 w-4" />
            </span>
            <div>
              <h2 className="text-base font-semibold text-slate-900 dark:text-slate-100">
                AI Tutor
              </h2>
              <p className="text-sm text-slate-500 dark:text-slate-400">
                Coach and Socratic tutor · mock responses
              </p>
            </div>
          </div>
        </CardHeader>
        <CardBody>
          <AiTutorChat />
        </CardBody>
      </Card>
    </div>
  );
}