// ABOUTME: Exercise plan reference page.
// ABOUTME: Displays the full monthly exercise plan by phase with current phase highlighted.
"use client";

import { useCallback, useEffect, useState } from "react";
import type { CyclePhase, PhaseConfig } from "@/types";

interface CycleData {
  cycleDay: number;
  phase: CyclePhase;
  phaseConfig: PhaseConfig;
  daysUntilNextPhase: number;
  cycleLength: number;
}

// Phase configurations for display
const PHASES: Array<{
  name: CyclePhase;
  displayName: string;
  weeklyLimit: number;
  trainingType: string;
  description: string;
}> = [
  {
    name: "MENSTRUAL",
    displayName: "Menstrual",
    weeklyLimit: 30,
    trainingType: "Gentle rebounding only",
    description: "Focus on rest and gentle movement. Light lymphatic drainage.",
  },
  {
    name: "FOLLICULAR",
    displayName: "Follicular",
    weeklyLimit: 120,
    trainingType: "Strength + rebounding",
    description:
      "Building phase - increase intensity and add strength training.",
  },
  {
    name: "OVULATION",
    displayName: "Ovulation",
    weeklyLimit: 80,
    trainingType: "Peak performance",
    description: "Peak energy - maximize intensity and plyometric movements.",
  },
  {
    name: "EARLY_LUTEAL",
    displayName: "Early Luteal",
    weeklyLimit: 100,
    trainingType: "Moderate training",
    description:
      "Maintain intensity but listen to your body for signs of fatigue.",
  },
  {
    name: "LATE_LUTEAL",
    displayName: "Late Luteal",
    weeklyLimit: 50,
    trainingType: "Gentle rebounding ONLY",
    description:
      "Wind down phase - focus on stress relief and gentle movement.",
  },
];

const STRENGTH_EXERCISES = [
  { name: "Squats", sets: "3x8-12" },
  { name: "Push-ups", sets: "3x5-10" },
  { name: "Single-leg Deadlifts", sets: "3x6-8 each" },
  { name: "Plank", sets: "3x20-45s" },
  { name: "Kettlebell Swings", sets: "2x10-15" },
];

const REBOUNDING_TECHNIQUES = [
  {
    phase: "Menstrual",
    techniques: "Health bounce, lymphatic drainage",
  },
  {
    phase: "Follicular",
    techniques: "Strength bounce, intervals",
  },
  {
    phase: "Ovulation",
    techniques: "Maximum intensity, plyometric",
  },
  {
    phase: "Luteal",
    techniques: "Therapeutic, stress relief",
  },
];

export default function PlanPage() {
  const [cycleData, setCycleData] = useState<CycleData | null>(null);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);

  const fetchCycleData = useCallback(async () => {
    const response = await fetch("/api/cycle/current");
    const data = await response.json();

    if (!response.ok) {
      throw new Error(data.error || "Failed to fetch cycle data");
    }

    return data as CycleData;
  }, []);

  useEffect(() => {
    async function loadData() {
      try {
        setLoading(true);
        setError(null);
        const data = await fetchCycleData();
        setCycleData(data);
      } catch (err) {
        setError(err instanceof Error ? err.message : "An error occurred");
      } finally {
        setLoading(false);
      }
    }

    loadData();
  }, [fetchCycleData]);

  if (loading) {
    return (
      <div className="container mx-auto p-8">
        <h1 className="text-2xl font-bold mb-8">Exercise Plan</h1>
        <p className="text-zinc-500">Loading...</p>
      </div>
    );
  }

  if (error) {
    return (
      <div className="container mx-auto p-8">
        <h1 className="text-2xl font-bold mb-8">Exercise Plan</h1>
        <div role="alert" className="text-red-500">
          Error: {error}
        </div>
      </div>
    );
  }

  return (
    <div className="container mx-auto p-8">
      <h1 className="text-2xl font-bold mb-8">Exercise Plan</h1>

      {cycleData && (
        <div className="space-y-8">
          {/* Current Phase Status */}
          <section className="bg-zinc-100 dark:bg-zinc-800 rounded-lg p-6">
            <h2 className="text-lg font-semibold mb-2">Current Status</h2>
            <p className="text-xl font-medium">
              Day {cycleData.cycleDay} · {cycleData.phase.replace("_", " ")}
            </p>
            <p className="text-zinc-600 dark:text-zinc-400">
              {cycleData.daysUntilNextPhase} days until next phase
            </p>
            <p className="mt-2">
              <span className="font-medium">Training type:</span>{" "}
              {cycleData.phaseConfig.trainingType}
            </p>
            <p>
              <span className="font-medium">Weekly limit:</span>{" "}
              {cycleData.phaseConfig.weeklyLimit} min/week
            </p>
          </section>

          {/* Phase Overview */}
          <section>
            <h2 className="text-lg font-semibold mb-4">Phase Overview</h2>
            <div className="grid gap-4 md:grid-cols-2 lg:grid-cols-3">
              {PHASES.map((phase) => (
                <div
                  key={phase.name}
                  data-testid={`phase-${phase.name}`}
                  className={`rounded-lg p-4 border ${
                    cycleData.phase === phase.name
                      ? "ring-2 ring-blue-500 bg-blue-50 dark:bg-blue-900/20"
                      : "bg-white dark:bg-zinc-900"
                  }`}
                >
                  <h3 className="font-semibold text-base">
                    {phase.displayName}
                  </h3>
                  <p className="text-sm text-zinc-600 dark:text-zinc-400 mt-1">
                    {phase.trainingType}
                  </p>
                  <p className="text-sm font-medium mt-2">
                    {phase.weeklyLimit} min/week
                  </p>
                  <p className="text-xs text-zinc-500 mt-2">
                    {phase.description}
                  </p>
                </div>
              ))}
            </div>
          </section>

          {/* Strength Training Reference */}
          <section>
            <h2 className="text-lg font-semibold mb-4">
              Strength Training (Follicular Phase)
            </h2>
            <p className="text-sm text-zinc-600 dark:text-zinc-400 mb-4">
              Mon/Wed/Fri during follicular phase (20-25 min per session)
            </p>
            <div className="bg-white dark:bg-zinc-900 rounded-lg border">
              <table className="w-full">
                <thead>
                  <tr className="border-b">
                    <th className="text-left p-3 font-medium">Exercise</th>
                    <th className="text-left p-3 font-medium">Sets × Reps</th>
                  </tr>
                </thead>
                <tbody>
                  {STRENGTH_EXERCISES.map((exercise) => (
                    <tr key={exercise.name} className="border-b last:border-0">
                      <td className="p-3">{exercise.name}</td>
                      <td className="p-3 text-zinc-600 dark:text-zinc-400">
                        {exercise.sets}
                      </td>
                    </tr>
                  ))}
                </tbody>
              </table>
            </div>
          </section>

          {/* Rebounding Techniques */}
          <section>
            <h2 className="text-lg font-semibold mb-4">
              Rebounding Techniques
            </h2>
            <p className="text-sm text-zinc-600 dark:text-zinc-400 mb-4">
              Adjust your rebounding style based on your current phase
            </p>
            <div className="grid gap-3 md:grid-cols-2">
              {REBOUNDING_TECHNIQUES.map((item) => (
                <div
                  key={item.phase}
                  className="bg-white dark:bg-zinc-900 rounded-lg border p-4"
                >
                  <h3 className="font-medium">{item.phase}</h3>
                  <p className="text-sm text-zinc-600 dark:text-zinc-400 mt-1">
                    {item.techniques}
                  </p>
                </div>
              ))}
            </div>
          </section>

          {/* Weekly Schedule Reference */}
          <section>
            <h2 className="text-lg font-semibold mb-4">Weekly Guidelines</h2>
            <div className="space-y-4">
              <div className="bg-white dark:bg-zinc-900 rounded-lg border p-4">
                <h3 className="font-medium">Menstrual Phase (Days 1-3)</h3>
                <ul className="text-sm text-zinc-600 dark:text-zinc-400 mt-2 list-disc pl-5 space-y-1">
                  <li>Morning: 10-15 min gentle rebounding</li>
                  <li>Evening: 15-20 min restorative movement</li>
                  <li>No strength training</li>
                </ul>
              </div>

              <div className="bg-white dark:bg-zinc-900 rounded-lg border p-4">
                <h3 className="font-medium">Follicular Phase (Days 4-14)</h3>
                <ul className="text-sm text-zinc-600 dark:text-zinc-400 mt-2 list-disc pl-5 space-y-1">
                  <li>Mon/Wed/Fri: Strength training (20-25 min)</li>
                  <li>Tue/Thu: Active recovery rebounding (20 min)</li>
                  <li>Weekend: Choose your adventure</li>
                </ul>
              </div>

              <div className="bg-white dark:bg-zinc-900 rounded-lg border p-4">
                <h3 className="font-medium">
                  Ovulation + Early Luteal (Days 15-24)
                </h3>
                <ul className="text-sm text-zinc-600 dark:text-zinc-400 mt-2 list-disc pl-5 space-y-1">
                  <li>Days 15-16: Peak performance (25-30 min strength)</li>
                  <li>
                    Days 17-21: Modified strength (reduce intensity 10-20%)
                  </li>
                </ul>
              </div>

              <div className="bg-white dark:bg-zinc-900 rounded-lg border p-4">
                <h3 className="font-medium">Late Luteal Phase (Days 22-28)</h3>
                <ul className="text-sm text-zinc-600 dark:text-zinc-400 mt-2 list-disc pl-5 space-y-1">
                  <li>Daily: Gentle rebounding only (15-20 min)</li>
                  <li>Optional light bodyweight Mon/Wed if feeling good</li>
                  <li>Rest days: Tue/Thu/Sat/Sun</li>
                </ul>
              </div>
            </div>
          </section>
        </div>
      )}
    </div>
  );
}