import React, { useEffect, useState } from "react";
import { Routes, Route, Navigate } from "react-router-dom";
import { Box, CircularProgress, Alert } from "@mui/material";
import { useAppContext } from "../context/AppContext";
import { Layout } from "./Layout";
import { ResourceList } from "./ResourceList";
import { ResourceForm } from "./ResourceForm";
import { ResourceDetail } from "./ResourceDetail";
import { ValidationAlert } from "./ValidationAlert";
import { getApi } from "../hooks/useApi";

export interface AdminProps {
  basePath: string;
}

export function Admin({ basePath }: AdminProps) {
  const { resources, loading, errors, warnings } = useAppContext();

  if (loading) {
    return (
      <Box sx={{ display: "flex", justifyContent: "center", alignItems: "center", height: "60vh" }}>
        <CircularProgress />
      </Box>
    );
  }

  if (errors.length > 0) {
    return <ValidationAlert errors={errors} warnings={warnings} />;
  }

  if (resources.length === 0) {
    return (
      <Box sx={{ p: 4, textAlign: "center" }}>
        No resources found in the OpenAPI spec.
      </Box>
    );
  }

  const topLevel = resources.filter((r) => !r.parent);

  return (
    <>
      {warnings.length > 0 && <ValidationAlert errors={[]} warnings={warnings} />}
      <Layout resources={topLevel} basePath={basePath}>
        <Routes>
          <Route index element={<Navigate to={`${basePath}/${topLevel[0]?.name ?? "profile"}`} replace />} />

          {topLevel.map((r) => (
            <React.Fragment key={r.name}>
              <Route path={r.name} element={<ResourceList resource={r} basePath={basePath} />} />
              {!r.streaming && (
                <>
                  <Route path={`${r.name}/new`} element={<ResourceForm resource={r} basePath={basePath} mode="create" />} />
                  <Route path={`${r.name}/:id`} element={<ResourceDetail resource={r} basePath={basePath} />} />
                  <Route path={`${r.name}/:id/edit`} element={<ResourceForm resource={r} basePath={basePath} mode="edit" />} />
                </>
              )}
            </React.Fragment>
          ))}
        </Routes>
      </Layout>
    </>
  );
}

export interface ProfileRoute {
  path: string;
  method: string;
  operationId: string;
  summary?: string;
}

/** Derive a friendly profile route path from the operation's spec path.
 *  e.g. "/users/me" → "me", "/users/me/" → "me" */
function friendlyProfilePath(specPath: string): string {
  return specPath.replace(/^\/[^/]+\/?/, "").replace(/\/+$/, "");
}

export function ProfileRoutes() {
  const { profileOperations, profileComponents } = useAppContext();
  const ops = profileOperations;
  const getOp = ops.find((o) => o.method === "GET");

  return (
    <Routes>
      <Route path=":username" element={<Navigate to="me" replace />} />
      {ops.map((op) => {
        const basePath = friendlyProfilePath(op.path);
        let Component: React.ComponentType<any> | undefined;
        let mode: "view" | "create" | "edit" | undefined;

        if (op.method === "GET" && profileComponents.view) {
          Component = profileComponents.view;
          mode = "view";
        } else if (op.method === "POST" && profileComponents.create) {
          Component = profileComponents.create;
          mode = "create";
        } else if ((op.method === "PUT" || op.method === "PATCH") && profileComponents.edit) {
          Component = profileComponents.edit;
          mode = "edit";
        }

        if (!Component || !mode) return null;

        const routePath = mode === "view" ? basePath : `${basePath}/edit`;

        return (
          <Route
            key={op.operationId}
            path={routePath}
            element={
              <ProfileComponentWrapper
                Component={Component}
                mode={mode}
                operation={op}
                getOperation={getOp}
              />
            }
          />
        );
      })}
    </Routes>
  );
}

function ProfileComponentWrapper({
  Component,
  mode,
  operation,
  getOperation,
}: {
  Component: React.ComponentType<any>;
  mode: "view" | "create" | "edit";
  operation: { path: string; method: string };
  getOperation?: { path: string };
}) {
  const [data, setData] = useState<any>(null);
  const [loading, setLoading] = useState(mode !== "create");
  const [error, setError] = useState<string | null>(null);

  const fetchPath = getOperation?.path ?? operation.path;

  const fetchData = async () => {
    setLoading(true);
    setError(null);
    try {
      const res = await getApi().get(fetchPath);
      setData(res.data);
    } catch (e: any) {
      setError(e.response?.data?.detail ?? e.message ?? "Failed to load profile");
    } finally {
      setLoading(false);
    }
  };

  useEffect(() => {
    if (mode !== "create") {
      fetchData();
    }
  }, [fetchPath, mode]);

  const handleSubmit = async (formData: Record<string, any>) => {
    setLoading(true);
    setError(null);
    try {
      if (mode === "create") {
        await getApi().post(operation.path, formData);
      } else {
        await getApi()({ method: operation.method.toLowerCase(), url: operation.path, data: formData });
      }
      // Navigate back to the base profile view path
      const base = friendlyProfilePath(operation.path);
      window.history.pushState(null, "", `/${base}`);
      window.location.reload();
    } catch (e: any) {
      setError(e.response?.data?.detail ?? e.message ?? "Operation failed");
    } finally {
      setLoading(false);
    }
  };

  if (loading && !data && mode !== "create") {
    return (
      <Box sx={{ display: "flex", justifyContent: "center", mt: 4 }}>
        <CircularProgress />
      </Box>
    );
  }

  if (error && !data && mode !== "create") {
    return (
      <Box sx={{ maxWidth: 480, mx: "auto", mt: 4 }}>
        <Alert severity="error">{error}</Alert>
      </Box>
    );
  }

  const props: Record<string, any> = {};

  if (mode === "view") {
    if (data) {
      props.name = data.name;
      props.username = data.username;
      props.email = data.email;
    }
    props.onEdit = () => {
      window.history.pushState(null, "", `/profile/me/edit`);
      window.location.reload();
    };
    props.loading = loading;
  }

  if (mode === "create") {
    props.defaultUsername = data?.username;
    props.defaultEmail = data?.email;
    props.onBack = () => window.history.back();
    props.onSubmit = handleSubmit;
    props.loading = loading;
    props.error = error;
  }

  if (mode === "edit") {
    if (data) {
      props.name = data.name;
      props.username = data.username;
      props.email = data.email;
    }
    props.onBack = () => window.history.back();
    props.onSubmit = handleSubmit;
    props.loading = loading;
    props.error = error;
  }

  return <Component {...props} />;
}