import { createSlice, createAsyncThunk, PayloadAction } from "@reduxjs/toolkit";
import Cookies from "js-cookie";
import type { AuthState, LoginPayload, User } from "@/types";
import { authService } from "@/services/auth.service";
import { COOKIE_KEYS } from "@/constants";

// ─── Initial State ────────────────────────────────────────────────────────────

const initialState: AuthState = {
  user: null,
  isAuthenticated: false,
  isLoading: false,
  error: null,
};

// ─── Async Thunks ─────────────────────────────────────────────────────────────

export const loginUser = createAsyncThunk(
  "auth/login",
  async (payload: LoginPayload, { rejectWithValue }) => {
    try {
      const response = await authService.login(payload);
      if (!response.success) {
        return rejectWithValue(response.message || "Login failed");
      }
      return response.data;
    } catch (error: unknown) {
      const err = error as { response?: { data?: { message?: string } } };
      return rejectWithValue(err?.response?.data?.message || "Login failed");
    }
  },
);

export const logoutUser = createAsyncThunk(
  "auth/logout",
  async (_, { rejectWithValue }) => {
    try {
      await authService.logout();
      return true;
    } catch {
      // Even if logout API fails, clear local state
      return true;
    }
  },
);

export const activateAccount = createAsyncThunk(
  "auth/activate",
  async (token: string, { rejectWithValue }) => {
    try {
      const response = await authService.activateAccount(token);
      if (!response.success) {
        return rejectWithValue(response.message || "Activation failed");
      }
      return response.data;
    } catch (error: unknown) {
      const err = error as { response?: { data?: { message?: string } } };
      return rejectWithValue(
        err?.response?.data?.message || "Activation failed",
      );
    }
  },
);

export const fetchCurrentUser = createAsyncThunk(
  "auth/fetchMe",
  async (_, { rejectWithValue }) => {
    try {
      const response = await authService.getMe();
      return response.data;
    } catch (error: unknown) {
      const err = error as { response?: { data?: { message?: string } } };
      return rejectWithValue(
        err?.response?.data?.message || "Failed to fetch user",
      );
    }
  },
);

// ─── Slice ────────────────────────────────────────────────────────────────────

const authSlice = createSlice({
  name: "auth",
  initialState,
  reducers: {
    setUser(state, action: PayloadAction<User>) {
      state.user = action.payload;
      state.isAuthenticated = true;
    },
    clearAuth(state) {
      state.user = null;
      state.isAuthenticated = false;
      state.error = null;
      Cookies.remove(COOKIE_KEYS.ACCESS_TOKEN);
    },
    clearError(state) {
      state.error = null;
    },
  },
  extraReducers: (builder) => {
    // Login
    builder
      .addCase(loginUser.pending, (state) => {
        state.isLoading = true;
        state.error = null;
      })
      .addCase(loginUser.fulfilled, (state, action) => {
        state.isLoading = false;
        state.user = action.payload;
        state.isAuthenticated = true;
        if (action.payload.access_token) {
          Cookies.set(COOKIE_KEYS.ACCESS_TOKEN, action.payload.access_token);
        }
      })
      .addCase(loginUser.rejected, (state, action) => {
        state.isLoading = false;
        state.error = action.payload as string;
      });

    // Logout
    builder.addCase(logoutUser.fulfilled, (state) => {
      state.user = null;
      state.isAuthenticated = false;
      state.isLoading = false;
      Cookies.remove(COOKIE_KEYS.ACCESS_TOKEN);
    });

    // Activate
    builder
      .addCase(activateAccount.pending, (state) => {
        state.isLoading = true;
        state.error = null;
      })
      .addCase(activateAccount.fulfilled, (state, action) => {
        state.isLoading = false;
        state.user = action.payload;
        state.isAuthenticated = true;
        if (action.payload.access_token) {
          Cookies.set(COOKIE_KEYS.ACCESS_TOKEN, action.payload.access_token);
        }
      })
      .addCase(activateAccount.rejected, (state, action) => {
        state.isLoading = false;
        state.error = action.payload as string;
      });

    // Fetch Me
    builder
      .addCase(fetchCurrentUser.pending, (state) => {
        state.isLoading = true;
      })
      .addCase(fetchCurrentUser.fulfilled, (state, action) => {
        state.isLoading = false;
        state.user = action.payload;
        state.isAuthenticated = true;
      })
      .addCase(fetchCurrentUser.rejected, (state) => {
        state.isLoading = false;
        state.user = null;
        state.isAuthenticated = false;
      });
  },
});

export const { setUser, clearAuth, clearError } = authSlice.actions;
export default authSlice.reducer;