#include "ListGraph.h"

#include <stdio.h>
#include <stdlib.h>

void init_list_graph(ListGraph *graph, int nodes) {
    /* TODO */
    graph->nodes = nodes;
    graph->neighbors = (LinkedList **)malloc(nodes * sizeof(LinkedList *));

    if (graph->neighbors == NULL) {
        fprintf(stderr, "List not initialised.\n");
        return;
    }

    for (int i = 0; i < nodes; ++i) {
        graph->neighbors[i] = (LinkedList *)malloc(sizeof(LinkedList));
        if (graph->neighbors[i] == NULL) {
            fprintf(stderr, "List not initialised.\n");
            return;
        }
        init_list(graph->neighbors[i]);
    }
}

void add_edge_list_graph(ListGraph *graph, int src, int *dest) {
    /* TODO */
    add_nth_node(graph->neighbors[src], graph->neighbors[src]->size, dest);
}

int has_edge_list_graph(ListGraph *graph, int src, int dest) {
    /* TODO */
    struct Node *curr;
    int found = 0;

    if (graph->neighbors[src] == NULL) {
        fprintf(stderr, "List not initialised.\n");
        return 0;
    }

    if (graph->neighbors[src]->size == 0) {
        return 0;
    }

    curr = graph->neighbors[src]->head;
    while (curr->next != NULL) {
        if (*((int *)curr->data) == dest) {
            found = 1;
            break;
        }
        curr = curr->next;
    }

    if (found == 1) {
        curr = graph->neighbors[dest]->head;
        while (curr->next != NULL) {
            if (*((int *)curr->data) == src) {
                return 1;
            }
            curr = curr->next;
        }
        fprintf(stderr, "Graph is not undirected.\n");
    }

    return 0;
}

LinkedList *get_neighbours_list_graph(ListGraph *graph, int node) {
    /* TODO */
    if (graph->neighbors[node] == NULL) {
        fprintf(stderr, "List not initialised.\n");
        return NULL;
    }

    return graph->neighbors[node];
}

void remove_edge_list_graph(ListGraph *graph, int src, int dest) {
    /* TODO */
    struct Node *curr, *tmp;
    int found = 0;

    if (graph->neighbors[src] == NULL) {
        fprintf(stderr, "List not initialised.\n");
        return;
    }

    if (graph->neighbors[dest] == NULL) {
        fprintf(stderr, "List not initialised.\n");
        return;
    }

    curr = graph->neighbors[src]->head;
    for (int i = 0; i < graph->neighbors[src]->size; ++i) {
        if (*(int *)curr->data == dest) {
            tmp = remove_nth_node(graph->neighbors[src], i);
            free(tmp);
            found = 1;
            break;
        } else if (i == graph->neighbors[src]->size - 1) {
            fprintf(stderr, "Element not found.\n");
            return;
        }
        curr = curr->next;
    }

    if (found == 1) {
        curr = graph->neighbors[dest]->head;
        for (int i = 0; i < graph->neighbors[dest]->size; ++i) {
            if (*(int *)curr->data == src) {
                tmp = remove_nth_node(graph->neighbors[dest], i);
                free(tmp);
                return;
            } else if (i == graph->neighbors[src]->size - 1) {
                fprintf(stderr, "Graph is not undirected.\n");
                return;
            }
            curr = curr->next;
        }
    }
}

void clear_list_graph(ListGraph *graph) {
    /* TODO */
    for (int i = 0; i < graph->nodes; ++i) {
        free_list(&graph->neighbors[i]);
    }
    free(graph->neighbors);
}