"use client";

import { useState } from "react";
import Link from "next/link";
import { useRouter } from "next/navigation";
import { toast } from "sonner";
import { CalendarIcon, PlayIcon, CheckCircleIcon, PlusIcon, TimerIcon } from "lucide-react";
import { Badge } from "@/components/ui/badge";
import { Button } from "@/components/ui/button";
import {
  Item,
  ItemContent,
  ItemDescription,
  ItemFooter,
  ItemHeader,
  ItemMedia,
  ItemTitle,
} from "@/components/ui/item";
import { Progress } from "@/components/ui/progress";
import { CreateSprintDialog } from "@/components/frontend/projects/CreateSprintDialog";
import { startSprint, completeSprint } from "@/app/(frontend)/projects/actions";
import { cn } from "@/lib/utils";

export interface SprintItem {
  readonly id: number;
  readonly name: string;
  readonly status: string;
  readonly goal?: string | null;
  readonly startDate?: string | null;
  readonly endDate?: string | null;
  readonly capacity?: number | null;
  readonly storyPointsCompleted: number;
  readonly storyPointsTotal: number;
}

export interface SprintsViewProps {
  readonly project: { id: number; name: string; key: string };
  readonly sprints: readonly SprintItem[];
  readonly isAdmin: boolean;
}

const SPRINT_STATUS_STYLES: Readonly<Record<string, string>> = {
  planning: "bg-zinc-500/15 text-zinc-400 border-zinc-500/30",
  active: "bg-emerald-500/15 text-emerald-400 border-emerald-500/30",
  completed: "bg-violet-500/15 text-violet-400 border-violet-500/30",
};

function labelFor(value: string): string {
  return value
    .replaceAll("_", " ")
    .replace(/\b\w/g, (character) => character.toUpperCase());
}

function dateFor(value: string | null | undefined): string {
  if (!value) return "TBD";
  return new Date(value).toLocaleDateString("en-US", {
    month: "short",
    day: "numeric",
    year: "numeric",
  });
}

export function SprintsView({ project, sprints, isAdmin }: SprintsViewProps) {
  const router = useRouter();
  const [createOpen, setCreateOpen] = useState(false);

  async function handleStartSprint(sprintId: number) {
    const result = await startSprint({ sprintId });
    if (result.success) {
      toast.success("Sprint started");
      router.refresh();
    } else {
      toast.error(result.error ?? "Failed to start sprint");
    }
  }

  async function handleCompleteSprint(sprintId: number) {
    const result = await completeSprint({ sprintId });
    if (result.success) {
      toast.success("Sprint completed");
      router.refresh();
    } else {
      toast.error(result.error ?? "Failed to complete sprint");
    }
  }

  return (
    <div className="flex flex-col gap-5">
      <div className="flex flex-wrap items-end justify-between gap-3">
        <div className="flex flex-col gap-1">
          <div className="flex items-center gap-2">
            <h2 className="text-sm font-semibold uppercase tracking-wider text-muted-foreground">Sprints</h2>
            <span className="text-xs text-muted-foreground">{sprints.length} total</span>
          </div>
          <p className="text-sm text-muted-foreground">Plan focused delivery windows and track progress.</p>
        </div>
        {isAdmin && (
          <Button size="sm" onClick={() => setCreateOpen(true)}>
            <PlusIcon data-icon="inline-start" />
            Create sprint
          </Button>
        )}
      </div>

      {sprints.length === 0 ? (
        <Item variant="outline">
          <ItemMedia variant="icon">
            <TimerIcon className="text-muted-foreground" />
          </ItemMedia>
          <ItemContent className="items-center gap-1">
            <ItemTitle>No sprints yet</ItemTitle>
            <ItemDescription>Create a sprint to start planning your work.</ItemDescription>
          </ItemContent>
        </Item>
      ) : (
        <div className="flex flex-col gap-2" role="list" aria-label={`${project.name} sprints`}>
          {sprints.map((sprint) => {
            const hasCapacity = sprint.capacity != null && sprint.capacity > 0;
            const usedPoints = hasCapacity ? Math.min(sprint.storyPointsTotal, sprint.capacity!) : 0;
            const progressPercent = hasCapacity ? Math.round((usedPoints / sprint.capacity!) * 100) : 0;

            return (
              <Item key={sprint.id} variant="outline" size="sm" role="listitem" className="items-start gap-3">
                <ItemHeader className="items-center">
                  <div className="flex min-w-0 items-center gap-2">
                    <ItemTitle className="truncate text-base font-semibold">{sprint.name}</ItemTitle>
                    <Badge
                      variant="outline"
                      className={cn(
                        "text-[10px] uppercase tracking-wide",
                        SPRINT_STATUS_STYLES[sprint.status] ?? "bg-muted/50 text-muted-foreground border-border",
                      )}
                    >
                      {labelFor(sprint.status)}
                    </Badge>
                  </div>
                  {isAdmin && (
                    <div className="flex gap-1">
                      {sprint.status === "planning" && (
                        <Button
                          variant="ghost"
                          size="sm"
                          onClick={() => void handleStartSprint(sprint.id)}
                          className="h-6 px-2 text-xs"
                        >
                          <PlayIcon className="size-3" />
                          Start
                        </Button>
                      )}
                      {sprint.status === "active" && (
                        <Button
                          variant="ghost"
                          size="sm"
                          onClick={() => void handleCompleteSprint(sprint.id)}
                          className="h-6 px-2 text-xs"
                        >
                          <CheckCircleIcon className="size-3" />
                          Complete
                        </Button>
                      )}
                    </div>
                  )}
                </ItemHeader>

                <ItemContent className="w-full min-w-0 gap-2">
                  {sprint.goal && <ItemDescription>{sprint.goal}</ItemDescription>}

                  {hasCapacity && (
                    <div className="flex flex-col gap-1">
                      <div className="flex justify-between text-xs text-muted-foreground">
                        <span>Story points: {sprint.storyPointsTotal} / {sprint.capacity}</span>
                        <span>{progressPercent}%</span>
                      </div>
                      <Progress value={progressPercent} className="h-1.5" />
                    </div>
                  )}

                  {!hasCapacity && (
                    <div className="text-xs text-muted-foreground">
                      Story points: {sprint.storyPointsTotal}
                    </div>
                  )}
                </ItemContent>

                <ItemFooter className="w-full flex-wrap justify-start gap-x-4 gap-y-1 text-xs text-muted-foreground">
                  <span className="flex items-center gap-1">
                    <CalendarIcon className="size-3" />
                    {dateFor(sprint.startDate)} — {dateFor(sprint.endDate)}
                  </span>
                </ItemFooter>
              </Item>
            );
          })}
        </div>
      )}

      <CreateSprintDialog projectId={project.id} open={createOpen} onOpenChange={setCreateOpen} />
    </div>
  );
}