"use client";

import { useEffect, useState } from "react";
import { UsersIcon } from "lucide-react";
import { toast } from "sonner";
import { fireStaff, setLaborHeadcount } from "@/app/(frontend)/logistics/base/actions";
import { Button } from "@/components/ui/button";
import { Card, CardContent, CardDescription, CardHeader, CardTitle } from "@/components/ui/card";
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
} from "@/components/ui/dialog";
import { Input } from "@/components/ui/input";
import { Label } from "@/components/ui/label";
import { Separator } from "@/components/ui/separator";
import { currencyLabel, formatAmount, type CurrencyConfig } from "@/lib/banking/format";
import type { LaborClassificationOption, StructureStaffingOption } from "@/lib/base";
import { HireStaffDialog } from "@/components/frontend/baseManagement/HireStaffDialog";

interface StaffMember {
  readonly id: number;
  readonly npcName: string | null;
  readonly positionType: string;
  readonly positionTitle: string;
  readonly salary: number;
  readonly headcount: number;
  readonly laborClassificationId: number | null;
  readonly hiredAt: string;
}

interface StaffRosterProps {
  readonly structure: StructureStaffingOption;
  readonly staff: readonly StaffMember[];
  readonly classifications: readonly LaborClassificationOption[];
  readonly npcs: readonly { id: number; name: string }[];
  readonly canManage: boolean;
  readonly hiringEnabled: boolean;
  readonly hiringDisabledMessage?: string;
  readonly currencyConfig: CurrencyConfig;
  readonly onChanged?: () => void;
}

interface LaborCrew {
  readonly classificationId: number;
  readonly classificationName: string;
  headcount: number;
  unitSalary: number;
  readonly requiredHeadcount: number;
  readonly maxHeadcount: number;
  readonly enforcedSalary: number | null;
}

interface LaborEdit {
  readonly headcount: string;
  readonly unitSalary: string;
}

export function StaffRoster({
  structure,
  staff,
  classifications,
  npcs,
  canManage,
  hiringEnabled,
  hiringDisabledMessage,
  currencyConfig,
  onChanged,
}: StaffRosterProps) {
  const [staffMembers, setStaffMembers] = useState<readonly StaffMember[]>(staff);
  const [fireTarget, setFireTarget] = useState<StaffMember | null>(null);
  const [loading, setLoading] = useState(false);
  const [laborLoading, setLaborLoading] = useState<number | null>(null);
  const [laborEdits, setLaborEdits] = useState<Record<number, LaborEdit>>({});

  useEffect(() => {
    setStaffMembers(staff);
    setLaborEdits({});
  }, [staff]);

  async function handleFire() {
    if (!fireTarget) return;

    setLoading(true);
    try {
      const result = await fireStaff(fireTarget.id);
      if (result.success) {
        toast.success(`${fireTarget.npcName} fired`);
        setStaffMembers((current) => current.filter((member) => member.id !== fireTarget.id));
        setFireTarget(null);
        onChanged?.();
      } else {
        toast.error(result.error ?? "Fire failed");
      }
    } catch {
      toast.error("Fire failed");
    } finally {
      setLoading(false);
    }
  }

  function getLaborEdit(crew: LaborCrew): LaborEdit {
    return (
      laborEdits[crew.classificationId] ?? {
        headcount: String(crew.headcount),
        unitSalary: String(crew.unitSalary),
      }
    );
  }

  function updateLaborEdit(crew: LaborCrew, field: keyof LaborEdit, value: string) {
    setLaborEdits((current) => {
      const edit =
        current[crew.classificationId] ??
        ({
          headcount: String(crew.headcount),
          unitSalary: String(crew.unitSalary),
        } satisfies LaborEdit);

      return {
        ...current,
        [crew.classificationId]: {
          ...edit,
          [field]: value,
        },
      };
    });
  }

  async function handleLaborSave(crew: LaborCrew) {
    const edit = getLaborEdit(crew);
    const headcount = Number(edit.headcount);
    const unitSalary = Number(edit.unitSalary) || 0;

    if (!Number.isInteger(headcount) || headcount < 0) {
      toast.error("Headcount must be a whole number of 0 or more.");
      return;
    }
    if (!Number.isFinite(unitSalary) || unitSalary < 0) {
      toast.error("Wage cannot be negative.");
      return;
    }

    setLaborLoading(crew.classificationId);
    try {
      const result = await setLaborHeadcount(
        structure.id,
        crew.classificationId,
        headcount,
        unitSalary,
      );
      if (!result.success) {
        toast.error(result.error ?? "Labor update failed");
        return;
      }

      const isCrew = (member: StaffMember) =>
        member.positionType === "labor" &&
        member.npcName === null &&
        member.laborClassificationId === crew.classificationId;

      const requirement = structure.laborRequirements.find(
        (entry) => entry.classificationId === crew.classificationId,
      );
      const effectiveUnitSalary = requirement?.enforcedSalary ?? unitSalary;
      if (headcount === 0) {
        setStaffMembers((current) => current.filter((member) => !isCrew(member)));
        toast.success(`${crew.classificationName} crew released`);
      } else {
        setStaffMembers((current) => {
          let keptCrew = false;
          return current.flatMap((member) => {
            if (!isCrew(member)) return [member];
            if (keptCrew) return [];
            keptCrew = true;
            return [{ ...member, headcount, salary: effectiveUnitSalary }];
          });
        });
        toast.success(`${crew.classificationName} crew updated`);
      }
      setLaborEdits((current) => {
        const next = { ...current };
        delete next[crew.classificationId];
        return next;
      });
      onChanged?.();
    } catch {
      toast.error("Labor update failed");
    } finally {
      setLaborLoading(null);
    }
  }

  const namedStaff = staffMembers.filter(
    (member) => !(member.positionType === "labor" && member.npcName === null),
  );
  const laborMembers = staffMembers.filter(
    (member) => member.positionType === "labor" && member.npcName === null,
  );
  const laborCrews = structure.laborRequirements.flatMap<LaborCrew>((requirement) => {
    const classification = classifications.find(
      (entry) => entry.id === requirement.classificationId,
    );
    if (!classification) return [];
    const members = laborMembers.filter(
      (member) => member.laborClassificationId === classification.id,
    );
    return [
      {
        classificationId: classification.id,
        classificationName: classification.name,
        headcount: members.reduce((sum, member) => sum + member.headcount, 0),
        unitSalary:
          requirement.enforcedSalary ?? members[0]?.salary ?? classification.defaultUnitSalary ?? 0,
        requiredHeadcount: requirement.requiredHeadcount,
        maxHeadcount: requirement.maxHeadcount,
        enforcedSalary: requirement.enforcedSalary,
      },
    ];
  });
  const showLaborSection =
    laborMembers.length > 0 ||
    structure.laborRequirements.length > 0 ||
    (canManage && structure.staffPositions.length > 0);

  return (
    <>
      <Card>
        <CardHeader className="gap-2">
          <CardTitle className="flex items-center gap-2">
            <UsersIcon className="size-4 text-muted-foreground" />
            Staff
          </CardTitle>
          <CardDescription>
            {staffMembers.length} active assignment{staffMembers.length === 1 ? "" : "s"}.
          </CardDescription>
          {structure.maintenanceCost > 0 && (
            <p className="text-sm text-muted-foreground">
              Maintenance: {formatAmount(structure.maintenanceCost, currencyConfig)}/tick
            </p>
          )}
        </CardHeader>
        <CardContent>
          {namedStaff.length === 0 && !showLaborSection ? (
            <p className="text-sm text-muted-foreground">No staff assigned to this structure.</p>
          ) : (
            <div className="flex flex-col gap-4">
              {namedStaff.length > 0 && (
                <div className="flex flex-col">
                  {namedStaff.map((member, index) => (
                    <div key={member.id}>
                      {index > 0 && <Separator />}
                      <div className="flex flex-wrap items-center justify-between gap-3 py-3 first:pt-0 last:pb-0">
                        <div className="min-w-0">
                          <p className="font-medium">{member.npcName}</p>
                          <p className="text-sm text-muted-foreground">
                            {member.positionTitle} · {member.positionType}
                          </p>
                        </div>
                        <div className="flex items-center gap-3">
                          <span className="shrink-0 font-mono text-sm tabular-nums">
                            {formatAmount(member.salary, currencyConfig)}/tick
                          </span>
                          {canManage && (
                            <Button
                              variant="outline"
                              size="sm"
                              className="border-destructive text-destructive hover:bg-destructive/10 hover:text-destructive"
                              onClick={() => setFireTarget(member)}
                            >
                              Fire
                            </Button>
                          )}
                        </div>
                      </div>
                    </div>
                  ))}
                </div>
              )}

              {showLaborSection && (
                <>
                  {namedStaff.length > 0 && <Separator />}
                  <div className="flex flex-col gap-3">
                    <div className="flex flex-wrap items-start justify-between gap-3">
                      <div>
                        <p className="font-medium">Labor crew</p>
                        <p className="text-sm text-muted-foreground">
                          Classification-based workers assigned to this structure.
                        </p>
                      </div>
                      {canManage && hiringEnabled && (
                        <HireStaffDialog
                          structures={[structure]}
                          npcs={npcs}
                          defaultStructureId={structure.id}
                          canManage={canManage}
                          classifications={classifications}
                          hiringEnabled={hiringEnabled}
                          hiringDisabledMessage={hiringDisabledMessage}
                          currencyConfig={currencyConfig}
                        />
                      )}
                    </div>

                    {!hiringEnabled && canManage && (
                      <p className="text-sm text-muted-foreground">
                        {hiringDisabledMessage || "Staff hiring is currently disabled."}
                      </p>
                    )}

                    {laborCrews.length === 0 ? (
                      <p className="text-sm text-muted-foreground">
                        No labor crew — add workers via Hire Staff.
                      </p>
                    ) : (
                      <div className="flex flex-col">
                        {laborCrews.map((crew, index) => {
                          const edit = getLaborEdit(crew);
                          const crewIsLoading = laborLoading === crew.classificationId;

                          return (
                            <div key={crew.classificationId}>
                              {index > 0 && <Separator />}
                              <div className="flex flex-col gap-3 py-3 first:pt-0 last:pb-0">
                                <div className="flex flex-wrap items-start justify-between gap-3">
                                  <div className="min-w-0">
                                    <p className="font-medium">
                                      {crew.classificationName} — {crew.headcount} hired ·{" "}
                                      {crew.requiredHeadcount} required · max {crew.maxHeadcount}
                                    </p>
                                    <p className="font-mono text-sm tabular-nums text-muted-foreground">
                                      {formatAmount(crew.unitSalary, currencyConfig)}/tick each ·{" "}
                                      {formatAmount(
                                        crew.unitSalary * crew.headcount,
                                        currencyConfig,
                                      )}
                                      /tick total
                                    </p>
                                  </div>
                                </div>

                                {canManage && (
                                  <div className="flex flex-col gap-3 sm:flex-row sm:items-end">
                                    <div className="flex flex-1 flex-col gap-1.5">
                                      <Label htmlFor={`labor-headcount-${crew.classificationId}`}>
                                        Headcount
                                      </Label>
                                      <Input
                                        id={`labor-headcount-${crew.classificationId}`}
                                        type="number"
                                        min={0}
                                        max={crew.maxHeadcount}
                                        step={1}
                                        inputMode="numeric"
                                        value={edit.headcount}
                                        onChange={(event) =>
                                          updateLaborEdit(crew, "headcount", event.target.value)
                                        }
                                        disabled={crewIsLoading || !hiringEnabled}
                                      />
                                    </div>
                                    <div className="flex flex-1 flex-col gap-1.5">
                                      <Label htmlFor={`labor-wage-${crew.classificationId}`}>
                                        Wage per worker ({currencyLabel(currencyConfig)})
                                      </Label>
                                      <Input
                                        id={`labor-wage-${crew.classificationId}`}
                                        type="number"
                                        min={0}
                                        step="any"
                                        value={edit.unitSalary}
                                        onChange={(event) =>
                                          updateLaborEdit(crew, "unitSalary", event.target.value)
                                        }
                                        disabled={
                                          crewIsLoading ||
                                          !hiringEnabled ||
                                          crew.enforcedSalary !== null
                                        }
                                      />
                                    </div>
                                    <Button
                                      variant="outline"
                                      size="sm"
                                      onClick={() => void handleLaborSave(crew)}
                                      disabled={crewIsLoading || !hiringEnabled}
                                    >
                                      {crewIsLoading
                                        ? "Saving..."
                                        : edit.headcount === "0"
                                          ? "Release crew"
                                          : "Apply"}
                                    </Button>
                                  </div>
                                )}
                              </div>
                            </div>
                          );
                        })}
                      </div>
                    )}
                  </div>
                </>
              )}
            </div>
          )}
        </CardContent>
      </Card>

      <Dialog
        open={fireTarget !== null}
        onOpenChange={(open) => {
          if (!open && !loading) setFireTarget(null);
        }}
      >
        <DialogContent>
          <DialogHeader>
            <DialogTitle>Fire {fireTarget?.npcName}?</DialogTitle>
            <DialogDescription>This ends their assignment.</DialogDescription>
          </DialogHeader>
          <DialogFooter>
            <Button variant="outline" onClick={() => setFireTarget(null)} disabled={loading}>
              Cancel
            </Button>
            <Button variant="destructive" onClick={() => void handleFire()} disabled={loading}>
              {loading ? "Firing..." : "Fire staff"}
            </Button>
          </DialogFooter>
        </DialogContent>
      </Dialog>
    </>
  );
}