import json
class Node:

    def __init__(self, item: int, track: json, next=None):
        self.item = item
        self.track = track
        self.next = next


class LinkedList:

    def __init__(self):
        self.head = None

    def find_by_value(self, value: int):
        # 根据值查找节点
        p = self.head
        while p and p.item != value:
            p = p.next
        return p

    def find_by_index(self, position: int):
        # 根据索引位置查找节点，需要挨个遍历
        p = self.head
        index = 0
        while p and index != position:
            p = p.next
            index += 1
        return p

    def insert_value_to_head(self, value: int, data: json):
        node = Node(value, data)
        self.insert_node_to_head(node)
        print(f"add node: {value}")

    def insert_node_to_head(self, node):
        if node:
            node.next = self.head
            self.head = node

    def insert_node_after(self, node, new_node):
        if not node or not new_node:
            return
        new_node.next = node.next
        node.next = new_node

    def insert_value_after(self, node, value, data):
        new_node = Node(value, data)
        self.insert_node_after(node, new_node)

    def insert_node_before(self, node, new_node):
        if not self.head or not node or not new_node:
            return

        if node == self.head:
            self.insert_node_to_head(new_node)
            return

        p = self.head
        while p and p.next != node:
            p = p.next

        if not p:
            return

        new_node.next = node
        p.next = new_node

    def insert_value_before(self, value: int, data: json, node):
        new_node = Node(value,data)
        self.insert_node_before(node, new_node)

    def delete_by_node(self, node):
        if not self.head or not node:
            return

        if node.next:
            node.item = node.next.item
            node.next = node.next.next

        p = self.head
        while p and p.next != node:
            p = p.next

        if not p:
            return

        p.next = node.next

    def delete_by_value(self, value: int, data: json):
        if not self.head or not value:
            return
        fake_head = Node(-1 , data)
        fake_head.next = self.head
        prev, current = fake_head, self.head
        while current:
            if current.item != value:
                prev.next = current
                prev = prev.next
            current = current.next

        if prev.next:  # current.item == value
            prev.next = prev.next.next
        self.head = fake_head.next
        print(f"delete node: {value}")
    def __repr__(self):
    	# print linklist，rewrite func repr or func str
        a = []
        p = self.head
        while p:
            a.append(p.track)
            p = p.next
        return " ".join(map(str, a))

                

if __name__ == '__main__':
    l = LinkedList()
    for i in range(10):
        l.insert_value_to_head(i, {"name":f"w{i}"})

    node = l.find_by_value(5)
    new_name = "newNames"
    l.insert_value_before(20, {"name":f"w{new_name}"}, node)
    l.insert_value_after(node, 24, {"name":f"wafterName"})
    print(l)