"use client";

import { useState } from "react";
import { trpc } from "~/lib/trpc/client.js";
import { DateInput } from "~/components/ui/DateInput.js";
import { SkillTagInput } from "~/components/ui/SkillTagInput.js";
import { InfoTooltip } from "~/components/ui/InfoTooltip.js";

export function StaffingPanel() {
  const [requiredSkills, setRequiredSkills] = useState<string[]>(["TypeScript", "React"]);
  const [startDate, setStartDate] = useState(new Date().toISOString().split("T")[0] ?? "");
  const [endDate, setEndDate] = useState(
    new Date(Date.now() + 90 * 24 * 60 * 60 * 1000).toISOString().split("T")[0] ?? "",
  );
  const [hoursPerDay, setHoursPerDay] = useState(8);
  const [submitted, setSubmitted] = useState(false);

  const { data: suggestions, isLoading } = trpc.staffing.getSuggestions.useQuery(
    {
      requiredSkills: requiredSkills,
      startDate: new Date(startDate),
      endDate: new Date(endDate),
      hoursPerDay,
    },
    { enabled: submitted },
  );

  return (
    <div className="app-page space-y-6">
      <div className="app-page-header gap-4">
        <div className="space-y-3">
          <span className="inline-flex items-center rounded-full border border-brand-200 bg-brand-50 px-3 py-1 text-[11px] font-semibold uppercase tracking-[0.24em] text-brand-700 dark:border-brand-900/60 dark:bg-brand-900/30 dark:text-brand-200">
            Staffing
          </span>
          <div>
            <h1 className="app-page-title">Staffing Suggestions</h1>
            <p className="app-page-subtitle max-w-2xl">
              Match open work with the strongest available people based on skills, availability, utilization, and cost.
            </p>
          </div>
        </div>
        <div className="app-surface max-w-xl p-4">
          <p className="text-sm font-medium text-gray-900 dark:text-gray-100">How scoring works</p>
          <p className="mt-1 text-sm text-gray-500">
            plANARCHY blends skill fit, free capacity, cost, and current utilization. Add the must-have skills first, then narrow the date window to get cleaner results.
          </p>
        </div>
      </div>

      <div className="grid grid-cols-1 gap-6 xl:grid-cols-[360px_minmax(0,1fr)]">
        <div className="space-y-6">
          <div className="app-surface-strong p-6">
            <h2 className="text-lg font-semibold text-gray-900 dark:text-gray-100">Search Criteria</h2>
            <p className="mt-1 text-sm text-gray-500">Define the role needs and let the matching engine rank the best candidates.</p>

            <div className="mt-6 space-y-5">
              <div>
                <label className="app-label">Required Skills<InfoTooltip content="Skills the candidate must have. The engine scores overlap and proficiency against this list." /></label>
                <SkillTagInput
                  value={requiredSkills}
                  onChange={setRequiredSkills}
                  placeholder="Add skill…"
                />
              </div>

              <div className="grid gap-4 sm:grid-cols-2 xl:grid-cols-1">
                <div>
                  <label className="app-label">Start Date</label>
                  <DateInput
                    value={startDate}
                    onChange={setStartDate}
                    className="app-input"
                  />
                </div>

                <div>
                  <label className="app-label">End Date</label>
                  <DateInput
                    value={endDate}
                    onChange={setEndDate}
                    min={startDate}
                    className="app-input"
                  />
                </div>
              </div>

              <div>
                <label className="app-label">Hours per Day<InfoTooltip content="Required hours per day for the role. Used to check conflicts and estimate capacity." /></label>
                <input
                  type="number"
                  value={hoursPerDay}
                  onChange={(e) => setHoursPerDay(Number(e.target.value))}
                  min={1}
                  max={24}
                  className="app-input"
                />
              </div>

              <button
                onClick={() => setSubmitted(true)}
                className="inline-flex w-full items-center justify-center rounded-xl bg-brand-600 px-4 py-3 text-sm font-semibold text-white transition hover:bg-brand-700"
              >
                Find Matches
              </button>
            </div>
          </div>

          <div className="app-surface p-5">
            <div className="grid grid-cols-3 gap-3 text-sm">
              <div>
                <div className="text-[11px] font-semibold uppercase tracking-[0.16em] text-gray-500">Skills</div>
                <div className="mt-1 text-gray-600 dark:text-gray-300">Quality of skill overlap with the requested stack.</div>
              </div>
              <div>
                <div className="text-[11px] font-semibold uppercase tracking-[0.16em] text-gray-500">Availability</div>
                <div className="mt-1 text-gray-600 dark:text-gray-300">Conflicts and free capacity during the selected period.</div>
              </div>
              <div>
                <div className="text-[11px] font-semibold uppercase tracking-[0.16em] text-gray-500">Cost + Load</div>
                <div className="mt-1 text-gray-600 dark:text-gray-300">Cost efficiency and current utilization weighting.</div>
              </div>
            </div>
          </div>
        </div>

        <div className="space-y-4">
          {isLoading && (
            <div className="app-surface-strong py-16 text-center text-sm text-gray-500">
              Finding best matches...
            </div>
          )}

          {suggestions && suggestions.length === 0 && (
            <div className="app-surface-strong py-16 text-center text-sm text-gray-500">
              No resources found matching your criteria.
            </div>
          )}

          {suggestions && suggestions.length > 0 && (
            <div className="space-y-4">
              {suggestions.map((suggestion, idx) => (
                <div key={suggestion.resourceId} className="app-surface p-5">
                  <div className="flex flex-col gap-4 lg:flex-row lg:items-start lg:justify-between">
                    <div className="flex items-center gap-4">
                      <div className="flex h-12 w-12 items-center justify-center rounded-2xl bg-brand-100 font-display text-lg font-semibold text-brand-700 dark:bg-brand-900/40 dark:text-brand-200">
                        {idx + 1}
                      </div>
                      <div>
                        <div className="text-base font-semibold text-gray-900 dark:text-gray-100">{suggestion.resourceName}</div>
                        <div className="text-sm text-gray-500">{suggestion.eid}</div>
                      </div>
                    </div>
                    <div className="rounded-2xl border border-brand-200 bg-brand-50 px-4 py-3 text-right dark:border-brand-900/50 dark:bg-brand-900/20">
                      <div className="text-[11px] font-semibold uppercase tracking-[0.18em] text-brand-700 dark:text-brand-200 inline-flex items-center gap-0.5">Match Score<InfoTooltip content="Composite score (0-100) blending skill fit, free capacity, cost efficiency, and current utilization." /></div>
                      <div className="mt-1 text-3xl font-semibold text-brand-700 dark:text-brand-100">{suggestion.score}</div>
                    </div>
                  </div>

                  <div className="mt-5 grid gap-3 sm:grid-cols-2 xl:grid-cols-4">
                    <ScoreBar label="Skills" value={suggestion.scoreBreakdown.skillScore} tooltip="Quality of skill overlap with the requested stack, weighted by proficiency level." />
                    <ScoreBar label="Availability" value={suggestion.scoreBreakdown.availabilityScore} tooltip="Free capacity during the selected period, accounting for existing bookings and vacations." />
                    <ScoreBar label="Cost" value={suggestion.scoreBreakdown.costScore} tooltip="Cost efficiency based on the resource's LCR relative to the team average." />
                    <ScoreBar label="Utilization" value={suggestion.scoreBreakdown.utilizationScore} tooltip="Current workload. Higher score means more capacity available (lower utilization)." />
                  </div>

                  <div className="mt-4 flex flex-wrap gap-2">
                    {suggestion.matchedSkills.map((skill) => (
                      <span key={skill} className="rounded-full bg-green-50 px-2.5 py-1 text-xs font-medium text-green-700 dark:bg-green-950/30 dark:text-green-300">
                        {skill}
                      </span>
                    ))}
                    {suggestion.missingSkills.map((skill) => (
                      <span key={skill} className="rounded-full bg-red-50 px-2.5 py-1 text-xs font-medium text-red-600 dark:bg-red-950/30 dark:text-red-300">
                        {skill} missing
                      </span>
                    ))}
                  </div>

                  <div className="mt-4 flex flex-wrap items-center gap-4 text-xs text-gray-500">
                    <span>LCR: {(suggestion.estimatedDailyCostCents / 100 / 8).toFixed(0)} €/h</span>
                    <span>Utilization: {Math.round(suggestion.currentUtilization)}%</span>
                    {suggestion.availabilityConflicts.length > 0 && (
                      <span className="font-medium text-amber-600 dark:text-amber-300">
                        {suggestion.availabilityConflicts.length} scheduling conflict{suggestion.availabilityConflicts.length === 1 ? "" : "s"}
                      </span>
                    )}
                  </div>
                </div>
              ))}
            </div>
          )}

          {!submitted && (
            <div className="app-surface-strong border-dashed py-20 text-center">
              <div className="mx-auto max-w-md">
                <div className="text-sm font-medium text-gray-900 dark:text-gray-100">No suggestions yet</div>
                <p className="mt-2 text-sm text-gray-500">
                  Add the required skills and date range, then run the search to see ranked staffing matches.
                </p>
              </div>
            </div>
          )}
        </div>
      </div>
    </div>
  );
}

function ScoreBar({ label, value, tooltip }: { label: string; value: number; tooltip?: string }) {
  return (
    <div className="rounded-2xl border border-gray-200 bg-gray-50/70 p-3 dark:border-gray-700 dark:bg-gray-900/40">
      <div className="mb-2 text-[11px] font-semibold uppercase tracking-[0.16em] text-gray-500 inline-flex items-center gap-0.5">{label}{tooltip && <InfoTooltip content={tooltip} />}</div>
      <div className="h-2 rounded-full bg-gray-200/80 dark:bg-gray-800">
        <div
          className="h-full rounded-full bg-brand-500"
          style={{ width: `${value}%` }}
        />
      </div>
      <div className="mt-2 text-sm font-medium text-gray-700 dark:text-gray-200">{value}</div>
    </div>
  );
}