//-----------------------------------------------------------------
// list_71.c:
//   ポインタによる構造体リストの並べ替え例
//-----------------------------------------------------------------
#include <stdio.h>
#include <malloc.h>
#include <string.h>
#include <stdlib.h>

enum COMP_TYPE {
    SORT_UK   = 0,
    SORT_DATE = 1,
};
enum SORT_TYPE {
    SORT_ASC  = 0,
    SORT_DESC = 1,
};

typedef struct entry *entry_ptr;
typedef struct entry{
    entry_ptr next;
    char scode[3+1];  // 支店コード
    char sname[10+1]; // 支店名
    char hday[8+1];   // 販売日
    char hcode[6+1];  // 販売先コード
    char hname[30+1]; // 販売先名
    int uk;           // 売上金額
} entry_type; // 構造体の型entry_typeの宣言

//-----------------------------------------------------------------
// 関数宣言
//-----------------------------------------------------------------
int uk_compare(int sort_type,entry_ptr x,entry_ptr y);
int date_compare(int sort_type,entry_ptr x,entry_ptr y);
void read_file(FILE** fp,entry_ptr* start);
void write_file(FILE** fp,entry_ptr start);
char* read_date(char* buf);
entry_ptr insert(char* x,char* buf,entry_ptr current);
void disp_list(entry_ptr start);
void sort_list(int ,entry_ptr* ,int compare(int ,entry_ptr ,entry_ptr ));
//-----------------------------------------------------------------

int main()
{
    FILE *infp,*outfp;
    int sort_type = SORT_ASC,comp_type;
    char filename[256];
    entry_ptr start;
    // 比較関数用関数ポインタ
    int (* const comp[2])(int ,entry_ptr,entry_ptr) = {
        uk_compare,date_compare
    };
    
    while(1){ // 入力ファイルのオープン
        printf("入力ファイル名(拡張子不要)---");
        infp = fopen(strcat(gets(filename),".txt"),"r");
        if(infp != NULL){        
            break;
        }
        perror("入力ファイルがオープンできません。\n");
    }
    while(1){ // 出力ファイルのオープン
        printf("出力ファイル名(拡張子不要)---");
        outfp = fopen(strcat(gets(filename),".txt"),"w");
        if(outfp != NULL){
            break;
        }
        perror("出力ファイルがオープンできません。\n");
    }
    // リストの読込み
    read_file(&infp,&start);
    // リスト全件の表示
    disp_list(start);
    
    // リストの並べ替え
    
    printf("**並べ替えを行うデータ:\n");
    printf("  -- 売上金額[0], 日付[1]: ");
    scanf("%d",&comp_type);
    if(comp_type != SORT_UK) comp_type = 1;

    printf("**並べ替えの種類:\n");
    printf("  -- 昇順[0], 降順[1]: ");
    scanf("%d",&sort_type);
    if(sort_type != SORT_ASC) sort_type = SORT_DESC;
    
    sort_list(sort_type,&start,comp[comp_type]);
    
    // リスト全件の表示
    disp_list(start);
    // 出力部分
    write_file(&outfp,start);
    
    fclose(infp);
    fclose(outfp);
    return 0;
}

int uk_compare(int sort_type,entry_ptr x,entry_ptr y)
{
    if(sort_type == SORT_ASC){
        if(x->uk < y->uk) return 1;
    } else {
        if(x->uk > y->uk) return 1;
    }
    return 0;
}

int date_compare(int sort_type,entry_ptr x,entry_ptr y)
{
    if(sort_type == SORT_ASC){
        if(strcmp(x->hday,y->hday) <= 0) return 1;
    } else {
        if(strcmp(x->hday,y->hday) >= 0) return 1;
    }
    return 0;
}

void read_file(FILE** fp,entry_ptr* start)
{
    char *x,buf[256];
    *start = NULL;
    while(fgets(buf,256,*fp) != NULL){
        x = read_date(buf);
        *start = insert(x,buf,*start);
    }
}

void write_file(FILE** fp,entry_ptr start)
{
    entry_ptr p;
    if(start == NULL) return;
    for(p=start;p!=NULL;p=p->next){
        fprintf(*fp,"%3s %10s %8s %6s %30s %10d\n",
                p->scode,
                p->sname,
                p->hday,
                p->hcode,
                p->hname,
                p->uk);
    }
}

char* read_date(char* buf)
{
    static char hday[8+1];
    char scode[3+1],sname[10+1],hcode[6+1],hname[30+1];
    int uk;
    sscanf(buf,"%3s %10s %8s %6s %30s %10d",
           scode,sname,hday,hcode,hname,&uk);
    return hday;
}

entry_ptr insert(char* x,char* buf,entry_ptr current)
{
    entry_ptr p;
    if(current == NULL) {
        p = (entry_ptr)malloc(sizeof(entry_type));
        sscanf(buf,"%3s %10s %8s %6s %30s %10d",
               p->scode,p->sname,
               p->hday,p->hcode,
               p->hname,&p->uk);
        p->next = NULL;
    } else {
        if(strcmp(current->hday,x) <= 0) {
            current->next = insert(x,buf,current->next);
            p = current;
        } else {
            p = (entry_ptr)malloc(sizeof(entry_type));
            sscanf(buf,"%3s %10s %8s %6s %30s %10d",
                   p->scode,p->sname,
                   p->hday,p->hcode,
                   p->hname,&p->uk);
            p->next = current;
        }
    }
    return(p);
}

void disp_list(entry_ptr start)
{
    entry_ptr p;
    printf("**リスト全件の表\示\n");
    if(start == NULL) return;
    for(p=start;p!=NULL;p=p->next){
        printf("%3s %10s %8s %6s %30s %10d\n",
               p->scode,p->sname,
               p->hday,p->hcode,
               p->hname,p->uk);
    }
}

void sort_list(int sort_type,entry_ptr* start,int compare(int ,entry_ptr ,entry_ptr ))
{
    entry_ptr p,pp,pre_p,pre_pp,tmp;
    pre_p = NULL;
    for(p=*start;p!=NULL;pre_p=p,p=p->next){
        pre_pp = p;
        for(pp=p->next;pp!=NULL;pre_pp=pp,pp=pp->next){
            if(compare(sort_type,p,pp)){
                if(pre_p){
                    pre_p->next = pp;
                }
                // 入れ替えるデータが隣り合わせる場合
                if(p == pre_pp){
                    p->next  = pp->next;
                    pp->next = p;
                } else {
                    tmp      = pp->next;
                    pp->next = p->next;
                    p->next  = tmp;
                    pre_pp->next = p;
                }
                // 入れ替え元が根の場合
                if(p == *start){
                    *start = pp;
                }
                tmp = p;
                p   = pp;
                pp  = tmp;
            }
        }
    }
}