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

#define MAXLEN 40
#define MAXNEIGHBOURS 10

int i;

struct country {
    char *name;
    int citizens;
    struct country *neighbours[MAXNEIGHBOURS];
    struct country *next;
};

void *addCountry(struct country **head, char *name, int *citizens) {
    struct country *curr = (*head);

    // create new node
    struct country *newcountry = (struct country*)malloc(sizeof(struct country));
    newcountry->name = (char *)malloc(strlen(name) + 1);
    strcpy(newcountry->name, name);
    newcountry->citizens = citizens;
    for (i = 0; i < MAXNEIGHBOURS; i++) {
        newcountry->neighbours[i] == NULL;
    }

    if (curr != NULL) {
        do {
            if (strcmp(curr->name, name) == 0) {
                printf("Country already exists\n");
                return;
            }
            curr = curr->next;
        } while (curr != *head);
    }
    curr = *head;

    if (curr == NULL) {
        // if list is still empty, loop back to self
        newcountry->next = newcountry;
        *head = newcountry;
    } else if (strcmp(curr->name, newcountry->name) > 0) {
        // if list needs to be inserted at the last pos
        while (curr->next != *head) {
            // look for last item before headref
            curr = curr->next;
        }
        // insert new country and move pointer to head to the new head
        curr->next = newcountry;
        newcountry->next = *head;
        *head = newcountry;
    } else {
        // for regular inserts
        while (curr->next != *head && (strcmp(curr->next->name, newcountry->name) < 0)) {
            // look for node after which the new node needs to be placed
            curr = curr->next;
        }
        newcountry->next = curr->next;
        curr->next = newcountry;
    }
    return;
};

void printList(struct country **head) {
    struct country *temp = (*head);
    float tempcit;

    if (temp!= NULL) {
        do {
            if (temp->citizens > 1000000) {
                tempcit = (float) temp->citizens / 1000000;
            } else {
                tempcit = (float) temp->citizens / 1000;
            }
            printf("name: %s, citizens: %0.1f", temp->name, tempcit);

            for (i = 0; i < MAXNEIGHBOURS; i++) {
                if (temp->neighbours[i] != NULL) {
                    printf(" -- neighbour %d: %s", i, temp->neighbours[i]->name);
                }
            }

            printf("\n");
            temp = temp->next;
        } while (temp != *head);

    } else {
        printf("List is empty\n");
    }

    return;
}

struct country *findCountry(struct country *search, char *name) {
    struct country *head = search;
    struct country *temp = search;

    if (search == NULL) {
        return NULL;
    }

    do {
        if (strcmp(temp->name, name) == 0) {
            return temp;
        }
        temp = temp->next;
    } while (temp != head);

    return NULL;
}

void addNeighbour(struct country *countries, char *n1name, char *n2name) {
    struct country *temp = countries;
    struct country *n1 = findCountry(countries, n1name);
    struct country *n2 = findCountry(countries, n2name);

    // check if both countries exist
    if (n1 == NULL) {
        printf("%s does not exist\n", n1name);
        return;
    } else if (n2 == NULL) {
        printf("%s does not exist\n", n2name);
        return;
    }


    for (i = 0; i < MAXNEIGHBOURS; i++) {
        // check if the neighbour isnt already in list
        if (n1->neighbours[i] == NULL) {
        // when finding an empty spot, add n2 to n1 neighbours and do same other way around
            n1->neighbours[i] = n2;
            for (i = 0; i < MAXNEIGHBOURS; i++) {
                if (n2->neighbours[i] == NULL) {
                    n2->neighbours[i] = n1;
                    printf("%s\n", n1->neighbours[0]->name);
                    return;
                }
            }
        }
    }
}

void removeCountry(struct country **head, char *name) {
    struct country *curr = (*remove);
    struct country *prev = (*remove);
    struct country *remove = findCountry((*head), name);

    if (remove == NULL) {
        printf("Country doesn't exist\n");
        return;
    }

    if (curr == NULL) {
        // if list is empty
        printf("list empty\n");
    } else if (strcmp((*head)->name, name) == 0) {
        // if node to be removed is head
        // look for last node
        while (curr->next != (*head)) {
            curr = curr->next;
        }
        (*head) = (*head)->next;
        curr->next = remove->next;
        free(remove->name);
        free(remove);
    } else {
        while (1) {

        }
    }
}

int main() {
    char cmd;
    char secondcmd[MAXLEN];
    char thirdcmd[MAXLEN];
    int intcmd = 123;
    float tempcit;

    struct country *countries = NULL;
    struct country *searchCountry = (struct country*)malloc(sizeof(struct country));

    while (1) {
        printf("Command? ");
        scanf(" %c", &cmd);

        switch(cmd) {
            case 'a':
                printf("name and number of citizens? ");
                scanf(" %s %d", secondcmd, &intcmd);
                addCountry(&countries, secondcmd, intcmd);
                break;
            case 'p':
                printList(&countries);
                break;
            case 'q':
                printf("Bye!");
                return;
                break;
            case 'f':
                printf("Name? ");
                scanf(" %s", secondcmd);
                searchCountry = findCountry(countries, secondcmd);
                if (searchCountry != NULL) {
                    if (searchCountry->citizens > 1000000) {
                        tempcit = (float) searchCountry->citizens / 1000000;
                    } else {
                        tempcit = (float) searchCountry->citizens / 1000;
                    }
                    printf("name: %s, citizens: %0.1f\n", searchCountry->name, tempcit);
                } else {
                    printf("Country not found\n");
                }
                break;
            case 'n':
                printf("Name of two countries? ");
                scanf(" %s %s", secondcmd, thirdcmd);
                addNeighbour(countries, secondcmd, thirdcmd);
                break;
            default:
                printf("invalid command: %c\n", cmd);
                break;
        }
    }
}