"use client";

import { useEffect, useState } from "react";
import { useSession } from "next-auth/react";
import { useParams } from "next/navigation";
import Link from "next/link";
import { ProjectCreationModal } from "@/components/project-creation-modal";
import {
  AlertDialog,
  AlertDialogAction,
  AlertDialogCancel,
  AlertDialogContent,
  AlertDialogDescription,
  AlertDialogFooter,
  AlertDialogHeader,
  AlertDialogTitle,
} from "@/components/ui/alert-dialog";
import { Loader2, Trash2 } from "lucide-react";
import { toast } from "sonner";

interface ProjectWithStats {
  id: string;
  productName: string;
  productVision?: string;
  status?: string;
  updatedAt: string | null;
  stats: { sessions: number; costs: number };
}

function timeAgo(dateStr?: string | null): string {
  if (!dateStr) return "—";
  const date = new Date(dateStr);
  if (isNaN(date.getTime())) return "—";
  const diff = (Date.now() - date.getTime()) / 1000;
  if (diff < 60) return "just now";
  if (diff < 3600) return `${Math.floor(diff / 60)}m ago`;
  if (diff < 86400) return `${Math.floor(diff / 3600)}h ago`;
  const days = Math.floor(diff / 86400);
  if (days === 1) return "Yesterday";
  if (days < 7) return `${days}d ago`;
  if (days < 30) return `${Math.floor(days / 7)}w ago`;
  return `${Math.floor(days / 30)}mo ago`;
}

function StatusDot({ status }: { status?: string }) {
  const color = status === "live" ? "#2e7d32" : status === "building" ? "#3d5afe" : "#d4a04a";
  const anim = status === "building" ? "vibn-breathe 2.5s ease infinite" : "none";
  return (
    <span style={{ width: 7, height: 7, borderRadius: "50%", background: color, display: "inline-block", flexShrink: 0, animation: anim }} />
  );
}

function StatusTag({ status }: { status?: string }) {
  const label = status === "live" ? "Live" : status === "building" ? "Building" : "Defining";
  const color = status === "live" ? "#2e7d32" : status === "building" ? "#3d5afe" : "#9a7b3a";
  const bg = status === "live" ? "#2e7d3210" : status === "building" ? "#3d5afe10" : "#d4a04a12";
  return (
    <span style={{
      display: "inline-flex", alignItems: "center", gap: 5,
      padding: "3px 9px", borderRadius: 4,
      fontSize: "0.68rem", fontWeight: 600, letterSpacing: "0.02em",
      color, background: bg, fontFamily: "Outfit, sans-serif",
    }}>
      <StatusDot status={status} /> {label}
    </span>
  );
}

export default function ProjectsPage() {
  const params = useParams();
  const workspace = params.workspace as string;
  const { data: session, status } = useSession();

  const [projects, setProjects] = useState<ProjectWithStats[]>([]);
  const [loading, setLoading] = useState(true);
  const [showNew, setShowNew] = useState(false);
  const [projectToDelete, setProjectToDelete] = useState<ProjectWithStats | null>(null);
  const [isDeleting, setIsDeleting] = useState(false);

  const fetchProjects = async () => {
    try {
      setLoading(true);
      const res = await fetch("/api/projects");
      if (!res.ok) throw new Error("Failed to fetch projects");
      const data = await res.json();
      setProjects(data.projects ?? []);
    } catch {
      /* silent */
    } finally {
      setLoading(false);
    }
  };

  useEffect(() => {
    if (status === "authenticated") fetchProjects();
    else if (status === "unauthenticated") setLoading(false);
  }, [status]);

  const handleDelete = async () => {
    if (!projectToDelete) return;
    setIsDeleting(true);
    try {
      const res = await fetch("/api/projects/delete", {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ projectId: projectToDelete.id }),
      });
      if (res.ok) {
        toast.success("Project deleted");
        setProjectToDelete(null);
        fetchProjects();
      } else {
        const err = await res.json();
        toast.error(err.error || "Failed to delete project");
      }
    } catch {
      toast.error("An error occurred");
    } finally {
      setIsDeleting(false);
    }
  };

  const statusSummary = () => {
    const live = projects.filter((p) => p.status === "live").length;
    const building = projects.filter((p) => p.status === "building").length;
    const defining = projects.filter((p) => !p.status || p.status === "defining").length;
    const parts = [];
    if (defining) parts.push(`${defining} defining`);
    if (building) parts.push(`${building} building`);
    if (live) parts.push(`${live} live`);
    return `${projects.length} total · ${parts.join(" · ")}`;
  };

  return (
    <div
      className="vibn-enter"
      style={{ padding: "44px 52px", maxWidth: 900, fontFamily: "Outfit, sans-serif" }}
    >
      {/* Header */}
      <div style={{ display: "flex", justifyContent: "space-between", alignItems: "flex-end", marginBottom: 36 }}>
        <div>
          <h1 style={{
            fontFamily: "Newsreader, serif", fontSize: "1.9rem",
            fontWeight: 400, color: "#1a1a1a", letterSpacing: "-0.03em",
            lineHeight: 1.15, marginBottom: 4,
          }}>
            Projects
          </h1>
          {!loading && (
            <p style={{ fontSize: "0.82rem", color: "#a09a90" }}>{statusSummary()}</p>
          )}
        </div>
        <button
          onClick={() => setShowNew(true)}
          style={{
            display: "flex", alignItems: "center", gap: 6,
            padding: "8px 16px", borderRadius: 7,
            background: "#1a1a1a", color: "#fff",
            border: "1px solid #1a1a1a",
            fontSize: "0.78rem", fontWeight: 600,
            fontFamily: "Outfit, sans-serif", cursor: "pointer",
          }}
        >
          <span style={{ fontSize: "1rem", lineHeight: 1, fontWeight: 300 }}>+</span>
          New project
        </button>
      </div>

      {/* Loading */}
      {loading && (
        <div style={{ display: "flex", justifyContent: "center", paddingTop: 64 }}>
          <Loader2 style={{ width: 28, height: 28, color: "#b5b0a6" }} className="animate-spin" />
        </div>
      )}

      {/* Project list */}
      {!loading && (
        <div style={{ display: "flex", flexDirection: "column", gap: 8 }}>
          {projects.map((p, i) => (
            <div
              key={p.id}
              className="vibn-enter"
              style={{ position: "relative", animationDelay: `${i * 0.05}s` }}
            >
              <Link
                href={`/${workspace}/project/${p.id}/overview`}
                style={{
                  width: "100%", display: "flex", alignItems: "center",
                  padding: "18px 22px", borderRadius: 10,
                  background: "#fff", border: "1px solid #e8e4dc",
                  cursor: "pointer", fontFamily: "Outfit, sans-serif",
                  textDecoration: "none", boxShadow: "0 1px 2px #1a1a1a05",
                  transition: "all 0.15s",
                }}
                onMouseEnter={(e) => {
                  e.currentTarget.style.borderColor = "#d0ccc4";
                  e.currentTarget.style.boxShadow = "0 2px 8px #1a1a1a0a";
                }}
                onMouseLeave={(e) => {
                  e.currentTarget.style.borderColor = "#e8e4dc";
                  e.currentTarget.style.boxShadow = "0 1px 2px #1a1a1a05";
                }}
              >
                {/* Project initial */}
                <div style={{
                  width: 36, height: 36, borderRadius: 9, marginRight: 16,
                  background: "#1a1a1a12",
                  display: "flex", alignItems: "center", justifyContent: "center",
                  flexShrink: 0,
                }}>
                  <span style={{
                    fontFamily: "Newsreader, serif",
                    fontSize: "1.05rem", fontWeight: 500, color: "#1a1a1a",
                  }}>
                    {p.productName[0]?.toUpperCase() ?? "P"}
                  </span>
                </div>

                {/* Name + vision */}
                <div style={{ flex: 1, minWidth: 0 }}>
                  <div style={{ display: "flex", alignItems: "center", gap: 8, marginBottom: 2 }}>
                    <span style={{ fontSize: "0.9rem", fontWeight: 600, color: "#1a1a1a" }}>
                      {p.productName}
                    </span>
                    <StatusTag status={p.status} />
                  </div>
                  {p.productVision && (
                    <span style={{ fontSize: "0.78rem", color: "#a09a90", display: "block", overflow: "hidden", textOverflow: "ellipsis", whiteSpace: "nowrap" }}>
                      {p.productVision}
                    </span>
                  )}
                </div>

                {/* Meta */}
                <div style={{ display: "flex", gap: 28, alignItems: "center", flexShrink: 0 }}>
                  <div style={{ textAlign: "right" }}>
                    <div style={{ fontSize: "0.62rem", color: "#b5b0a6", textTransform: "uppercase", letterSpacing: "0.06em", marginBottom: 2 }}>
                      Last active
                    </div>
                    <div style={{ fontSize: "0.78rem", color: "#6b6560" }}>{timeAgo(p.updatedAt)}</div>
                  </div>
                  <div style={{ textAlign: "right" }}>
                    <div style={{ fontSize: "0.62rem", color: "#b5b0a6", textTransform: "uppercase", letterSpacing: "0.06em", marginBottom: 2 }}>
                      Sessions
                    </div>
                    <div style={{ fontSize: "0.78rem", color: "#6b6560" }}>{p.stats.sessions}</div>
                  </div>
                </div>

                {/* Delete (hover) */}
                <button
                  onClick={(e) => { e.preventDefault(); setProjectToDelete(p); }}
                  style={{
                    marginLeft: 16, padding: "5px 8px", borderRadius: 6,
                    border: "none", background: "transparent",
                    color: "#b5b0a6", cursor: "pointer",
                    opacity: 0, transition: "opacity 0.15s",
                    fontFamily: "Outfit, sans-serif",
                  }}
                  className="delete-btn"
                  onMouseEnter={(e) => e.currentTarget.style.color = "#d32f2f"}
                  onMouseLeave={(e) => e.currentTarget.style.color = "#b5b0a6"}
                  title="Delete project"
                >
                  <Trash2 style={{ width: 14, height: 14 }} />
                </button>
              </Link>
            </div>
          ))}

          {/* New project card */}
          <button
            onClick={() => setShowNew(true)}
            style={{
              width: "100%", display: "flex", alignItems: "center", justifyContent: "center",
              padding: "22px", borderRadius: 10,
              background: "transparent", border: "1px dashed #d0ccc4",
              cursor: "pointer", fontFamily: "Outfit, sans-serif",
              color: "#b5b0a6", fontSize: "0.84rem", fontWeight: 500,
              transition: "all 0.15s",
              animationDelay: `${projects.length * 0.05}s`,
            }}
            className="vibn-enter"
            onMouseEnter={(e) => { e.currentTarget.style.borderColor = "#8a8478"; e.currentTarget.style.color = "#6b6560"; }}
            onMouseLeave={(e) => { e.currentTarget.style.borderColor = "#d0ccc4"; e.currentTarget.style.color = "#b5b0a6"; }}
          >
            + New project
          </button>
        </div>
      )}

      {/* Empty state */}
      {!loading && projects.length === 0 && (
        <div style={{ textAlign: "center", paddingTop: 64 }}>
          <h3 style={{ fontFamily: "Newsreader, serif", fontSize: "1.3rem", fontWeight: 400, color: "#1a1a1a", marginBottom: 8 }}>
            No projects yet
          </h3>
          <p style={{ fontSize: "0.82rem", color: "#a09a90", lineHeight: 1.6, marginBottom: 24 }}>
            Tell Atlas what you want to build and it will figure out the rest.
          </p>
          <button
            onClick={() => setShowNew(true)}
            style={{
              padding: "10px 22px", borderRadius: 7,
              background: "#1a1a1a", color: "#fff",
              border: "none", fontSize: "0.84rem", fontWeight: 600,
              fontFamily: "Outfit, sans-serif", cursor: "pointer",
            }}
          >
            Create your first project
          </button>
        </div>
      )}

      <ProjectCreationModal
        open={showNew}
        onOpenChange={(open) => { setShowNew(open); if (!open) fetchProjects(); }}
        workspace={workspace}
      />

      <AlertDialog open={!!projectToDelete} onOpenChange={(open) => !open && setProjectToDelete(null)}>
        <AlertDialogContent>
          <AlertDialogHeader>
            <AlertDialogTitle>Delete &quot;{projectToDelete?.productName}&quot;?</AlertDialogTitle>
            <AlertDialogDescription>
              This will remove the project record. Sessions will be preserved but unlinked.
              The Gitea repo will not be deleted automatically.
            </AlertDialogDescription>
          </AlertDialogHeader>
          <AlertDialogFooter>
            <AlertDialogCancel disabled={isDeleting}>Cancel</AlertDialogCancel>
            <AlertDialogAction
              onClick={handleDelete}
              disabled={isDeleting}
              className="bg-red-600 hover:bg-red-700"
            >
              {isDeleting ? <Loader2 className="mr-2 h-4 w-4 animate-spin" /> : <Trash2 className="mr-2 h-4 w-4" />}
              Delete Project
            </AlertDialogAction>
          </AlertDialogFooter>
        </AlertDialogContent>
      </AlertDialog>
    </div>
  );
}
