// routes/auth/validate.ts
import { setCookie } from "$std/http/cookie.ts";
import { decode } from "djwt";
import { generateNonce, hashText } from "../../services/stateMiddleware.ts";
import { define } from "../../utils.ts";
import * as Iron from "iron";
import {
  getAllStateKeys,
  getStateKeys,
  getUserTokens,
  setStateKey,
  setUserTokens,
} from "../../services/userService.ts";
import {
  generatePassword,
  IdTokenPayload,
  isSecureRequest,
  persistWithEncryptedCookie,
  SessionCookie,
} from "./callback.ts";
import { KvCacheStore } from "../../modules/KvCacheStore.ts";
import { StateKey } from "../../db/interfaces.ts";
import { sqlGetAllStateKeys } from "../../db/sqlUserRepository.ts";

const persistPath = Deno.env.get("KV_CACHE_PATH") ?? "./data";

export const handler = define.handlers({
  async POST(ctx) {
    try {
      console.log("validate POST - validating tokens");

      const redirectHome = Deno.env.get("REDIRECT_HOME") || "";

      // Parse body - support both JSON and form data
      let body: {
        session?: string;
        xx_state_id?: string;
        caller_url?: string;
      };

      try {
        const contentType = ctx.req.headers.get("content-type") || "";

        if (contentType.includes("application/json")) {
          // Parse as JSON
          body = await ctx.req.json();
        } else if (
          contentType.includes("application/x-www-form-urlencoded") ||
          contentType.includes("multipart/form-data")
        ) {
          // Parse as form data
          const formData = await ctx.req.formData();
          body = {
            session: formData.get("session")?.toString(),
            xx_state_id: formData.get("xx_state_id")?.toString(),
            caller_url: formData.get("caller_url")?.toString(),
          };
        } else {
          // Try JSON as fallback
          body = await ctx.req.json();
        }
      } catch (_e) {
        console.error("Failed to parse request body:", _e);
        return new Response(null, {
          status: 302,
          headers: {
            "Location": "/",
          },
        });
      }

      console.log("validate POST - body:", body);

      const xxStateId = body.xx_state_id;
      const sessionCookie = body.session;
      const timestampNow = Date.now();
      let sessionData: SessionCookie | null = null;
      let theStateKey: string | null = null;

      if (xxStateId && sessionCookie) {
        const kvStore = await KvCacheStore.initialize(persistPath);
        const keys: StateKey[] = [];
        for await (
          const entry of kvStore.list<StateKey>({ prefix: ["state_keys"] })
        ) {
          keys.push(entry.value);
        }
        const allStateKeys = keys;
        console.log("validate POST - allStateKeys:", allStateKeys);
        let stateKeys = allStateKeys.filter((k) => k.state_id === xxStateId);
        if (!stateKeys || stateKeys.length === 0) {
          stateKeys = await sqlGetAllStateKeys();
          console.log("validate POST - sql stateKeys:", stateKeys);
        }

        stateKeys.sort((a: any, b: any) => b.created_on - a.created_on);
        const timestamp = timestampNow - 18000000;
        console.log("validate POST - stateKeys:", stateKeys);
        for (const stateKey of stateKeys) {
          let stateData: SessionCookie | null = null;

          try {
            stateData = await Iron.unseal(
              sessionCookie,
              stateKey.seal_key,
              Iron.defaults,
            ) as SessionCookie;
          } catch (_e) {
            console.log("error unsealing cookie");
          }

          if (stateData && stateData.user_id) {
            const thisHash = await hashText(JSON.stringify(stateData));
            if (thisHash === stateKey.cookie_hash) {
              const renewWindow = timestampNow - 300 * 1000;
              const newKey = generatePassword();
              if (stateKey.created_on < renewWindow) {
                stateData.started_on = timestampNow;
                const cookieHash = await hashText(JSON.stringify(stateData));
                await setStateKey(newKey, xxStateId, cookieHash);
                theStateKey = newKey;
              } else {
                theStateKey = stateKey.seal_key;
              }

              sessionData = stateData;
              break;
            }
          }
        }
      }

      console.log("validate POST - sessionData:", sessionData);
      const userId = sessionData?.user_id;
      const callerUrl = body.caller_url || redirectHome;

      const userTokens = userId ? await getUserTokens(userId) : null;

      if (!xxStateId || !sessionCookie || !userId || !userTokens) {
        console.error("Missing refresh_token in request body");
        return new Response(null, {
          status: 302,
          headers: {
            "Location": "/",
          },
        });
      }

      const nonce = generateNonce();
      const tokenEndpoint = Deno.env.get("TOKEN_URL") || "";
      const clientId = Deno.env.get("CLIENT_ID") || "";
      const clientSecret = Deno.env.get("CLIENT_SECRET") || "";

      const tokens = {
        access_token: "",
        id_token: "",
        refresh_token: "",
      };

      // Make refresh token request to validate and get new tokens
      const params = new URLSearchParams();
      params.append("client_id", clientId);
      params.append("client_secret", clientSecret);
      params.append("grant_type", "refresh_token");
      params.append("refresh_token", userTokens.refresh_token);
      params.append(
        "scope",
        `openid profile offline_access https://graph.microsoft.com/.default`,
      );

      const tokenResponse = await fetch(
        `${tokenEndpoint}?nonce=${nonce}`,
        {
          method: "POST",
          headers: { "Content-Type": "application/x-www-form-urlencoded" },
          body: params,
        },
      );

      if (!tokenResponse.ok) {
        console.error(
          "Failed to refresh token:",
          tokenResponse.status,
          await tokenResponse.text(),
        );
        return new Response(null, {
          status: 302,
          headers: {
            "Location": "/",
          },
        });
      }

      const tokenData = await tokenResponse.json();
      tokens.access_token = tokenData.access_token;
      tokens.id_token = tokenData.id_token;
      tokens.refresh_token = tokenData.refresh_token;

      const response = new Response(null, {
        status: 302,
        headers: {
          "Location": callerUrl,
          "nonce": nonce,
        },
      });

      // Decode id_token to extract session data
      try {
        const [header, payload, signature] = decode(
          tokens.id_token,
        );

        if (payload) {
          const p = payload as unknown as IdTokenPayload;
          const roles = Array.isArray(p.roles) && p.roles.length > 0
            ? p.roles.join(",")
            : "";
          sessionData = {
            started_on: Date.now(),
            user_name: p.name || p.preferred_username || p.email || "",
            user_id: p.oid || p.sub || "",
            user_encrypted: false,
            role: roles,
          };
          const newKey = generatePassword();
          const cookieHash = await hashText(JSON.stringify(sessionData));
          const success = await setStateKey(newKey, xxStateId, cookieHash);
          theStateKey = newKey;
          if (!success) {
            console.error("Failed to set state key");

            return new Response(null, {
              status: 302,
              headers: {
                "Location": "/",
              },
            });
          }
        }
      } catch (_e) {
        console.error("Failed to decode id_token:", _e);
        return new Response(null, {
          status: 302,
          headers: {
            "Location": "/",
          },
        });
      }

      setUserTokens(
        userId,
        xxStateId,
        tokens.access_token,
        tokens.refresh_token,
      );

      setCookie(response.headers, {
        name: "xx_state_id",
        value: xxStateId,
        httpOnly: true,
        secure: isSecureRequest(ctx.req),
        sameSite: "Lax",
        path: "/",
      });

      return theStateKey && sessionData
        ? persistWithEncryptedCookie(
          sessionData as SessionCookie,
          theStateKey,
          response,
          ctx.req,
          xxStateId,
        )
        : response;
    } catch (e) {
      console.error("Validation error:", e);
      return new Response(null, {
        status: 302,
        headers: {
          "Location": "/",
        },
      });
    }
  },
});