import { createSlice, createAsyncThunk, PayloadAction } from "@reduxjs/toolkit";
import { fetchClient } from "@/lib/api/fetchClient";
import Cookies from "js-cookie";

// Types
export interface Permission {
    id: number;
    name: string;
    description: string;
}

export interface Role {
    id: number;
    name: string;
    description: string;
    permissions?: Permission[] | null;
}

export interface SocialAccount {
    id: number;
    provider: string;
    email: string;
}

export interface User {
    id: string;
    username: string;
    email: string;
    roles: Role[];
    avatar_url?: string;
    email_verified?: boolean;
    is_oauth_user?: boolean;
    social_accounts?: SocialAccount[];
    created_at?: string;
    updated_at?: string;
}

interface AuthState {
    user: User | null;
    isAuthenticated: boolean;
    isLoading: boolean;
    error: string | null;
}

interface LoginResponse {
    user_id: string;
    username: string;
    email: string;
    access_token: string;
    refresh_token: string;
    roles: Role[];
    avatar?: string;
}

interface RegisterResponse {
    user_id: string;
    username: string;
    email: string;
    avatar: string;
    email_verified: boolean;
    message: string;
    roles: Role[];
    verification_token: string;
}

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

// Async Thunks
export const login = createAsyncThunk(
    "auth/login",
    async (credentials: any, { rejectWithValue }) => {
        try {
            const response: LoginResponse = await fetchClient("/auth/login", {
                method: "POST",
                body: JSON.stringify(credentials),
            });

            // Validate Check: Ensure tokens exist
            if (!response.access_token || !response.refresh_token) {
                return rejectWithValue("Giriş başarısız: Token alınamadı. Lütfen emailinizi doğruladığınızdan emin olun.");
            }

            // Store tokens in cookies
            Cookies.set("access_token", response.access_token, { secure: true, sameSite: 'strict' });
            Cookies.set("refresh_token", response.refresh_token, { secure: true, sameSite: 'strict' });

            // Store user info in localStorage for convenience (optional, can be removed if strict cookie only)
            if (typeof window !== "undefined") {
                localStorage.setItem("user", JSON.stringify({
                    id: response.user_id,
                    username: response.username,
                    email: response.email,
                    roles: response.roles,
                    avatar_url: response.avatar
                }));
            }

            return response;
        } catch (error: any) {
            return rejectWithValue(error.message);
        }
    }
);

export const register = createAsyncThunk(
    "auth/register",
    async (credentials: any, { rejectWithValue }) => {
        try {
            const response: RegisterResponse = await fetchClient("/auth/register", {
                method: "POST",
                body: JSON.stringify(credentials),
            });

            // NOTE: Register does NOT return tokens anymore.
            // We do NOT set cookies here.
            // We do NOT set localStorage user here.

            return response;
        } catch (error: any) {
            return rejectWithValue(error.message);
        }
    }
);

export const fetchProfile = createAsyncThunk(
    "auth/fetchProfile",
    async (_, { rejectWithValue }) => {
        try {
            const response = await fetchClient("/profile");
            const data = response as any;
            // Map API response to User type, specifically avatar -> avatar_url
            return {
                ...data,
                avatar_url: data.avatar,
                roles: data.roles || []
            } as User;
        } catch (error: any) {
            return rejectWithValue(error.message);
        }
    }
);

export const updateProfile = createAsyncThunk(
    "auth/updateProfile",
    async (formData: FormData, { rejectWithValue }) => {
        try {
            const response = await fetchClient("/profile", {
                method: "PUT",
                body: formData,
            });

            const data = (response as any).user;

            // Map API response to User type, specifically avatar -> avatar_url
            return {
                ...data,
                avatar_url: data.avatar,
                roles: data.roles || []
            } as User;
        } catch (error: any) {
            return rejectWithValue(error.message);
        }
    }
);

export const changePassword = createAsyncThunk(
    "auth/changePassword",
    async (data: any, { rejectWithValue }) => {
        try {
            const response = await fetchClient("/profile/password", {
                method: "PUT",
                body: JSON.stringify(data),
            });
            return response;
        } catch (error: any) {
            return rejectWithValue(error.message);
        }
    }
);

export const changeEmail = createAsyncThunk(
    "auth/changeEmail",
    async (data: any, { rejectWithValue }) => {
        try {
            const response = await fetchClient("/profile/email", {
                method: "PUT",
                body: JSON.stringify(data),
            });
            return response;
        } catch (error: any) {
            return rejectWithValue(error.message);
        }
    }
);

// Slice
const authSlice = createSlice({
    name: "auth",
    initialState,
    reducers: {
        logout: (state) => {
            state.user = null;
            state.isAuthenticated = false;
            state.error = null;
            Cookies.remove("access_token");
            Cookies.remove("refresh_token");
            if (typeof window !== "undefined") {
                localStorage.removeItem("user");
            }
        },
        restoreSession: (state) => {
            if (typeof window !== "undefined") {
                const userStr = localStorage.getItem("user");
                const token = Cookies.get("access_token");
                if (userStr && token) {
                    try {
                        const parsedUser = JSON.parse(userStr);
                        // Migration for legacy data: map avatar to avatar_url if needed
                        if (parsedUser.avatar && !parsedUser.avatar_url) {
                            parsedUser.avatar_url = parsedUser.avatar;
                        }
                        state.user = parsedUser;
                        state.isAuthenticated = true;
                    } catch (e) {
                        // Corrupt user data
                        localStorage.removeItem("user");
                        Cookies.remove("access_token");
                        Cookies.remove("refresh_token");
                    }
                }
            }
        }
    },
    extraReducers: (builder) => {
        // Login
        builder.addCase(login.pending, (state) => {
            state.isLoading = true;
            state.error = null;
        });
        builder.addCase(login.fulfilled, (state, action) => {
            state.isLoading = false;
            state.isAuthenticated = true;
            state.user = {
                id: action.payload.user_id,
                username: action.payload.username,
                email: action.payload.email,
                roles: action.payload.roles,
                avatar_url: action.payload.avatar
            };
        });
        builder.addCase(login.rejected, (state, action) => {
            state.isLoading = false;
            state.error = action.payload as string;
        });

        // Register
        builder.addCase(register.pending, (state) => {
            state.isLoading = true;
            state.error = null;
        });
        builder.addCase(register.fulfilled, (state, action) => {
            state.isLoading = false;
            // isAuthenticated remains false because we need email verification
            state.isAuthenticated = false;
            // We do not set the user state effectively until they login
            state.user = null;
        });
        builder.addCase(register.rejected, (state, action) => {
            state.isLoading = false;
            state.error = action.payload as string;
        });

        // Fetch Profile
        builder.addCase(fetchProfile.fulfilled, (state, action) => {
            state.user = action.payload;
            // Sync with localStorage so next refresh has fresh data
            if (typeof window !== "undefined") {
                localStorage.setItem("user", JSON.stringify(action.payload));
            }
        });

        // Update Profile
        builder.addCase(updateProfile.fulfilled, (state, action) => {
            state.user = action.payload;
            // Sync with localStorage so next refresh has fresh data
            if (typeof window !== "undefined") {
                localStorage.setItem("user", JSON.stringify(action.payload));
            }
        });
    },
});

export const { logout, restoreSession } = authSlice.actions;
export default authSlice.reducer;