import React from 'react';
import { makeStyles } from '@material-ui/core/styles';
import List from '@material-ui/core/List';
import ListItem from '@material-ui/core/ListItem';
import ListItemText from '@material-ui/core/ListItemText';
import ListSubheader from '@material-ui/core/ListSubheader';
import ExpandLess from '@material-ui/icons/ExpandLess';
import ExpandMore from '@material-ui/icons/ExpandMore';
import Collapse from '@material-ui/core/Collapse';

import { user_query_from_browsed_album, user_query_from_browsed_tag } from './queries';

class NavTreeItem {
    display_name = false;
    data = false;
    children = [];

    constructor(display_name, data, children) {
        this.display_name = display_name;
        this.data = data;
        this.children = children;
    }
}

export function split_path(path) {
    var r = path.split("/");
    if(path[0] === '/') { r.shift(); }
    return r;
}

export function insert_into_album_tree(treebaseitem, treeitem) {
    var parts = split_path(treeitem.data);
    var current_item = treebaseitem;
    for (var i = 0; i < parts.length; i++) {
        var part = parts[i];
        var subitem = false;
        var required_path = (current_item.data === "/") ?
            current_item.data + part :
            current_item.data + "/" + part;

        for (var j = 0; j < current_item.children.length; j++) {
            var child = current_item.children[j];
            if (child.data === required_path) {
                subitem = child;
                break;
            }
        }
        if (!subitem) {
            var new_sub = new NavTreeItem(
                part,
                required_path,
                []
            );
            current_item.children.push(new_sub);
            subitem = new_sub;
        }
        current_item = subitem;
    };
}

export function build_albums_tree(all_db_albums) {
    var tree = new NavTreeItem("", "/", []);
    for (var i = 0; i < all_db_albums.length; i++) {
        var album = all_db_albums[i];
        if (album.state.relative_path !== "/") { // we already made the base, skip that one
            var item = new NavTreeItem(
                album.state.name,
                album.state.relative_path,
                []
            );
            insert_into_album_tree(tree, item);
        }
    };
    return tree;
}

export function insert_into_tag_tree(treebaseitem, treeitem) {
    var parts = split_path(treeitem.data);
    var current_item = treebaseitem;
    for (var i = 0; i < parts.length; i++) {
        var part = parts[i];
        var subitem = false;
        var required_path = (current_item.data === "") ?
            current_item.data + part :
            current_item.data + "/" + part;

        for (var j = 0; j < current_item.children.length; j++) {
            var child = current_item.children[j];
            if (child.data === required_path) {
                subitem = child;
                break;
            }
        }
        if (!subitem) {
            var new_sub = new NavTreeItem(
                part,
                required_path,
                []
            );
            current_item.children.push(new_sub);
            subitem = new_sub;
        }
        current_item = subitem;
    };
}

export function build_tags_tree(all_db_tags) {
    var tree = new NavTreeItem("", "", []);
    for (var i = 0; i < all_db_tags.length; i++) {
        var tag = all_db_tags[i];
        var item = new NavTreeItem(
            tag.state.name,
            tag.state.fullname,
            []
        );
        insert_into_tag_tree(tree, item);
    };

    return tree;
}

const useStyles = makeStyles(theme => ({
    root: {
        width: '100%',
        maxWidth: 360,
        color: theme.color,
    },
    nested: {
        paddingLeft: theme.spacing(4),
        color: theme.color,
    },
}));

export function NavListItem(props) {
    const classes = useStyles();
    const [open, setOpen] = React.useState(false);
    const { navitem, onSelect } = props;

    const handleExpandClick = () => {
        setOpen(!open);
    }

    const handleClick = () => {
        if (onSelect) {
            onSelect(navitem);
        }
    }

    if (navitem.children.length === 0) {
        return (
            <ListItem button onClick={handleClick}>
                <ListItemText primary={navitem.display_name} />
            </ListItem>
        )
    } else {
        return (
            <>
                <ListItem button >
                    <ListItemText primary={navitem.display_name} onClick={handleClick} />
                    {open ? <ExpandLess onClick={handleExpandClick} /> : <ExpandMore onClick={handleExpandClick} />}
                </ListItem>
                <Collapse in={open} timeout="auto" unmountOnExit>
                    <List component="nav" className={classes.nested}>
                        {
                            navitem.children.map(elem => {
                                return <NavListItem navitem={elem} onSelect={onSelect} />
                            })
                        }
                    </List>
                </Collapse>
            </>
        )
    }
}

export function Browser(props) {
    const classes = useStyles();
    const { albums, tags, onNewQuery } = props;

    const propagateQuery = (query) => {
        if (onNewQuery) {
            onNewQuery(query);
        }
    }

    const propagateAlbumQuery = (navitem) => {
        propagateQuery(
            user_query_from_browsed_album(navitem.data)
        );
    }

    const propagateTagQuery = (navitem) => {
        propagateQuery(
            user_query_from_browsed_tag(navitem.data)
        );
    }

    const albums_tree = build_albums_tree(albums);
    const tags_tree = build_tags_tree(tags);

    return (
        <>
            <List
                component="nav"
                aria-labelledby="nested-list-subheader"
                subheader={
                    <ListSubheader component="div" id="nested-list-subheader">
                        Album Navigation
            </ListSubheader>
                }
                className={classes.root}
            >
                {
                    albums_tree.children.map(elem => {
                        return <NavListItem navitem={elem} onSelect={propagateAlbumQuery} />
                    })
                }
            </List>
            <List
                component="nav"
                aria-labelledby="nested-list-subheader"
                subheader={
                    <ListSubheader component="div" id="nested-list-subheader">
                        Tag Navigation
            </ListSubheader>
                }
                className={classes.root}
            >
                {
                    tags_tree.children.map(elem => {
                        return <NavListItem navitem={elem} onSelect={propagateTagQuery} />
                    })
                }
            </List>
        </>
    )
}