import { createSlice, createAsyncThunk, PayloadAction } from '@reduxjs/toolkit';
import axios from '../../axios';

// ─── Типы ────────────────────────────────────────────

type Status = 'idle' | 'loading' | 'successful' | 'failed';

export interface Article {
    id: number;
    authorId: number;
    name: string;
    content: string;
    tags: string[];
    createdAt: string;
    updatedAt: string;
}

interface ArticlesState {
    articles: Article[];
    currentArticle?: Article;
    hasNextPage: boolean;
    statuses: {
        create: Status;
        update: Status;
        delete: Status;
        fetchAll: Status;
        fetchById: Status;
    };
    error: string | null;
}

const initialState: ArticlesState = {
    articles: [],
    currentArticle: undefined,
    hasNextPage: false,
    statuses: {
        create: 'idle',
        update: 'idle',
        delete: 'idle',
        fetchAll: 'idle',
        fetchById: 'idle',
    },
    error: null,
};

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

// POST /articles
export const createArticle = createAsyncThunk(
    'articles/createArticle',
    async (
        {
            name,
            content,
            tags,
        }: { name: string; content: string; tags: string[] },
        { rejectWithValue },
    ) => {
        try {
            const response = await axios.post('/articles', {
                name,
                content,
                tags,
            });
            return response.data as Article;
        } catch (err: any) {
            return rejectWithValue(
                err.response?.data?.message || 'Ошибка при создании статьи',
            );
        }
    },
);

// PUT /articles/{articleId}
export const updateArticle = createAsyncThunk(
    'articles/updateArticle',
    async (
        {
            articleId,
            name,
            content,
            tags,
        }: { articleId: number; name: string; content: string; tags: string[] },
        { rejectWithValue },
    ) => {
        try {
            const response = await axios.put(`/articles/${articleId}`, {
                name,
                content,
                tags,
            });
            return response.data as Article;
        } catch (err: any) {
            return rejectWithValue(
                err.response?.data?.message || 'Ошибка при обновлении статьи',
            );
        }
    },
);

// DELETE /articles/{articleId}
export const deleteArticle = createAsyncThunk(
    'articles/deleteArticle',
    async (articleId: number, { rejectWithValue }) => {
        try {
            await axios.delete(`/articles/${articleId}`);
            return articleId;
        } catch (err: any) {
            return rejectWithValue(
                err.response?.data?.message || 'Ошибка при удалении статьи',
            );
        }
    },
);

// GET /articles
export const fetchArticles = createAsyncThunk(
    'articles/fetchArticles',
    async (
        {
            page = 0,
            pageSize = 10,
            tags,
        }: { page?: number; pageSize?: number; tags?: string[] },
        { rejectWithValue },
    ) => {
        try {
            const params: any = { page, pageSize };
            if (tags && tags.length > 0) params.tags = tags;
            const response = await axios.get('/articles', { params });
            return response.data as {
                hasNextPage: boolean;
                articles: Article[];
            };
        } catch (err: any) {
            return rejectWithValue(
                err.response?.data?.message || 'Ошибка при получении статей',
            );
        }
    },
);

// GET /articles/{articleId}
export const fetchArticleById = createAsyncThunk(
    'articles/fetchArticleById',
    async (articleId: number, { rejectWithValue }) => {
        try {
            const response = await axios.get(`/articles/${articleId}`);
            return response.data as Article;
        } catch (err: any) {
            return rejectWithValue(
                err.response?.data?.message || 'Ошибка при получении статьи',
            );
        }
    },
);

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

const articlesSlice = createSlice({
    name: 'articles',
    initialState,
    reducers: {
        clearCurrentArticle: (state) => {
            state.currentArticle = undefined;
        },
        setArticlesStatus: (
            state,
            action: PayloadAction<{
                key: keyof ArticlesState['statuses'];
                status: Status;
            }>,
        ) => {
            const { key, status } = action.payload;
            state.statuses[key] = status;
        },
    },
    extraReducers: (builder) => {
        // ─── CREATE ARTICLE ───
        builder.addCase(createArticle.pending, (state) => {
            state.statuses.create = 'loading';
            state.error = null;
        });
        builder.addCase(
            createArticle.fulfilled,
            (state, action: PayloadAction<Article>) => {
                state.statuses.create = 'successful';
                state.articles.push(action.payload);
            },
        );
        builder.addCase(
            createArticle.rejected,
            (state, action: PayloadAction<any>) => {
                state.statuses.create = 'failed';
                state.error = action.payload;
            },
        );

        // ─── UPDATE ARTICLE ───
        builder.addCase(updateArticle.pending, (state) => {
            state.statuses.update = 'loading';
            state.error = null;
        });
        builder.addCase(
            updateArticle.fulfilled,
            (state, action: PayloadAction<Article>) => {
                state.statuses.update = 'successful';
                const index = state.articles.findIndex(
                    (a) => a.id === action.payload.id,
                );
                if (index !== -1) state.articles[index] = action.payload;
                if (state.currentArticle?.id === action.payload.id)
                    state.currentArticle = action.payload;
            },
        );
        builder.addCase(
            updateArticle.rejected,
            (state, action: PayloadAction<any>) => {
                state.statuses.update = 'failed';
                state.error = action.payload;
            },
        );

        // ─── DELETE ARTICLE ───
        builder.addCase(deleteArticle.pending, (state) => {
            state.statuses.delete = 'loading';
            state.error = null;
        });
        builder.addCase(
            deleteArticle.fulfilled,
            (state, action: PayloadAction<number>) => {
                state.statuses.delete = 'successful';
                state.articles = state.articles.filter(
                    (a) => a.id !== action.payload,
                );
                if (state.currentArticle?.id === action.payload)
                    state.currentArticle = undefined;
            },
        );
        builder.addCase(
            deleteArticle.rejected,
            (state, action: PayloadAction<any>) => {
                state.statuses.delete = 'failed';
                state.error = action.payload;
            },
        );

        // ─── FETCH ARTICLES ───
        builder.addCase(fetchArticles.pending, (state) => {
            state.statuses.fetchAll = 'loading';
            state.error = null;
        });
        builder.addCase(
            fetchArticles.fulfilled,
            (
                state,
                action: PayloadAction<{
                    hasNextPage: boolean;
                    articles: Article[];
                }>,
            ) => {
                state.statuses.fetchAll = 'successful';
                state.articles = action.payload.articles;
                state.hasNextPage = action.payload.hasNextPage;
            },
        );
        builder.addCase(
            fetchArticles.rejected,
            (state, action: PayloadAction<any>) => {
                state.statuses.fetchAll = 'failed';
                state.error = action.payload;
            },
        );

        // ─── FETCH ARTICLE BY ID ───
        builder.addCase(fetchArticleById.pending, (state) => {
            state.statuses.fetchById = 'loading';
            state.error = null;
        });
        builder.addCase(
            fetchArticleById.fulfilled,
            (state, action: PayloadAction<Article>) => {
                state.statuses.fetchById = 'successful';
                state.currentArticle = action.payload;
            },
        );
        builder.addCase(
            fetchArticleById.rejected,
            (state, action: PayloadAction<any>) => {
                state.statuses.fetchById = 'failed';
                state.error = action.payload;
            },
        );
    },
});

export const { clearCurrentArticle, setArticlesStatus } = articlesSlice.actions;
export const articlesReducer = articlesSlice.reducer;