#include <dirent.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>
#include "trainlog/generation_mtp.h"

typedef struct Node { uint32_t id,parent; bool folder; char path[1024],name[256]; uint64_t size; } Node;
static Node nodes[2048]; static size_t node_count; static const char *remote;
static uint32_t scan(const char *path,uint32_t parent){DIR *d;struct dirent *e;uint32_t self=(uint32_t)(node_count+1U);Node *n=&nodes[node_count++];struct stat st;lstat(path,&st);n->id=self;n->parent=parent;n->folder=S_ISDIR(st.st_mode);n->size=(uint64_t)st.st_size;snprintf(n->path,sizeof(n->path),"%s",path);const char *slash=strrchr(path,'/');snprintf(n->name,sizeof(n->name),"%s",slash?slash+1:path);if(n->folder&&(d=opendir(path))!=NULL){while((e=readdir(d)))if(strcmp(e->d_name,".")&&strcmp(e->d_name,"..")){char child[1024];snprintf(child,sizeof(child),"%s/%s",path,e->d_name);scan(child,self);}closedir(d);}return self;}
static void rebuild(void){node_count=0U;scan(remote,UINT32_MAX);}
static Node *node(uint32_t id){size_t i;for(i=0;i<node_count;i++)if(nodes[i].id==id)return &nodes[i];return NULL;}
static TrainlogStatus devices(TrainlogUsbDevice *o,size_t c,size_t *n){if(c<1U)return TRAINLOG_STATUS_INVALID_ARGUMENT;memset(o,0,sizeof(*o));o->bus_number=1;o->device_number=1;*n=1;return TRAINLOG_STATUS_OK;}
static TrainlogStatus storages(unsigned int b,unsigned int d,TrainlogMtpStorage *o,size_t c,size_t *n){(void)b;(void)d;if(c<1U)return TRAINLOG_STATUS_INVALID_ARGUMENT;memset(o,0,sizeof(*o));o->storage_id=1;*n=1;return TRAINLOG_STATUS_OK;}
static TrainlogStatus children(unsigned int b,unsigned int d,uint32_t s,uint32_t p,TrainlogMtpEntry *o,size_t c,size_t *n){size_t i,k=0;(void)b;(void)d;(void)s;rebuild();if(p==UINT32_MAX)p=nodes[0].id;for(i=0;i<node_count;i++)if(nodes[i].parent==p){if(k>=c)return TRAINLOG_STATUS_INVALID_ARGUMENT;memset(&o[k],0,sizeof(o[k]));o[k].item_id=nodes[i].id;o[k].parent_id=p;o[k].storage_id=1;o[k].folder=nodes[i].folder;o[k].size_bytes=nodes[i].size;snprintf(o[k].name,sizeof(o[k].name),"%s",nodes[i].name);k++;}*n=k;return TRAINLOG_STATUS_OK;}
static TrainlogStatus ensure(unsigned int b,unsigned int d,uint32_t s,uint32_t p,const char *name,uint32_t *id,bool *created){Node *parent;char path[1024];(void)b;(void)d;(void)s;rebuild();parent=node(p);if(!parent)return TRAINLOG_STATUS_NOT_FOUND;snprintf(path,sizeof(path),"%s/%s",parent->path,name);if(mkdir(path,0700)==0)*created=true;else if(access(path,F_OK)==0)*created=false;else return TRAINLOG_STATUS_SYSTEM_ERROR;rebuild();size_t i;for(i=0;i<node_count;i++)if(strcmp(nodes[i].path,path)==0){*id=nodes[i].id;return TRAINLOG_STATUS_OK;}return TRAINLOG_STATUS_SYSTEM_ERROR;}
static int copy(const char *a,const char *b){FILE *in=fopen(a,"rb"),*out=fopen(b,"wb");char buf[8192];size_t n;if(!in||!out)return -1;while((n=fread(buf,1,sizeof(buf),in))>0)if(fwrite(buf,1,n,out)!=n)return -1;return fclose(in)|fclose(out);}
static TrainlogStatus receive(unsigned int b,unsigned int d,uint32_t id,const char *path){Node *n;(void)b;(void)d;rebuild();n=node(id);return n&&copy(n->path,path)==0?TRAINLOG_STATUS_OK:TRAINLOG_STATUS_SYSTEM_ERROR;}
static TrainlogStatus send_file(unsigned int b,unsigned int d,uint32_t s,uint32_t p,const char *local,const char *name,uint32_t *id){Node *parent;char path[1024];(void)b;(void)d;(void)s;rebuild();parent=node(p);if(!parent)return TRAINLOG_STATUS_NOT_FOUND;snprintf(path,sizeof(path),"%s/%s",parent->path,name);if(copy(local,path)!=0)return TRAINLOG_STATUS_SYSTEM_ERROR;rebuild();size_t i;for(i=0;i<node_count;i++)if(strcmp(nodes[i].path,path)==0){*id=nodes[i].id;return TRAINLOG_STATUS_OK;}return TRAINLOG_STATUS_SYSTEM_ERROR;}
static TrainlogStatus remove_object(unsigned int b,unsigned int d,uint32_t id){Node *n;(void)b;(void)d;rebuild();n=node(id);return n&&unlink(n->path)==0?TRAINLOG_STATUS_OK:TRAINLOG_STATUS_SYSTEM_ERROR;}
static TrainlogStatus rename_object(unsigned int b,unsigned int d,uint32_t id,const char *name){Node *n;char path[1024],*slash;(void)b;(void)d;rebuild();n=node(id);if(!n)return TRAINLOG_STATUS_NOT_FOUND;snprintf(path,sizeof(path),"%s",n->path);slash=strrchr(path,'/');if(!slash)return TRAINLOG_STATUS_SYSTEM_ERROR;snprintf(slash+1,(size_t)(path+sizeof(path)-(slash+1)),"%s",name);return rename(n->path,path)==0?TRAINLOG_STATUS_OK:TRAINLOG_STATUS_SYSTEM_ERROR;}
static const TrainlogGenerationMtpIo io={devices,storages,children,ensure,receive,send_file,remove_object,rename_object};
int main(int argc,char **argv){char diag[1024]={0};TrainlogStatus status;remote=getenv("TRAINLOG_MTP_DOUBLE_ROOT");if(argc!=4||!remote)return 64;if(strcmp(argv[1],"pull")==0)status=trainlog_generation_mtp_pull(&io,argv[2],argv[3],diag,sizeof(diag));else if(strcmp(argv[1],"push")==0)status=trainlog_generation_mtp_push(&io,argv[2],argv[3],diag,sizeof(diag));else return 64;if(status!=TRAINLOG_STATUS_OK){fprintf(stderr,"double failed %d %s\n",status,diag);return 2;}return 0;}