#include "config.h"
#include "local-store.hh"
#include "globals.hh"
#include "archive.hh"
#include "pathlocks.hh"
#include "worker-protocol.hh"
#include "derivations.hh"
#include "affinity.hh"

#include <iostream>
#include <algorithm>
#include <cstring>

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <unistd.h>
#include <utime.h>
#include <fcntl.h>
#include <errno.h>
#include <stdio.h>
#include <time.h>
#include <grp.h>
#include <ctype.h>

#if HAVE_UNSHARE && HAVE_STATVFS && HAVE_SYS_MOUNT_H
#include <sched.h>
#include <sys/statvfs.h>
#include <sys/mount.h>
#endif

#include <sys/ioctl.h>
#include <errno.h>

#include <sqlite3.h>


namespace nix {


void checkStoreNotSymlink()
{
    if (getEnv("NIX_IGNORE_SYMLINK_STORE") == "1") return;
    Path path = settings.nixStore;
    struct stat st;
    while (path != "/") {
        if (lstat(path.c_str(), &st))
            throw SysError(format("getting status of `%1%'") % path);
        if (S_ISLNK(st.st_mode))
            throw Error(format(
                "the path `%1%' is a symlink; "
                "this is not allowed for the store and its parent directories")
                % path);
        path = dirOf(path);
    }
}


LocalStore::LocalStore(bool reserveSpace)
{
    schemaPath = settings.nixDBPath + "/schema";

    if (settings.readOnlyMode) {
        openDB(false);
        return;
    }

    /* Create missing state directories if they don't already exist. */
    createDirs(settings.nixStore);
    makeStoreWritable();
    createDirs(linksDir = settings.nixStore + "/.links");
    Path profilesDir = settings.nixStateDir + "/profiles";
    createDirs(profilesDir);
    createDirs(settings.nixStateDir + "/temproots");
    createDirs(settings.nixDBPath);
    Path gcRootsDir = settings.nixStateDir + "/gcroots";
    if (!pathExists(gcRootsDir)) {
        createDirs(gcRootsDir);
        createSymlink(profilesDir, gcRootsDir + "/profiles");
    }

    /* Optionally, create directories and set permissions for a
       multi-user install. */
    if (getuid() == 0 && settings.buildUsersGroup != "") {

        Path perUserDir = profilesDir + "/per-user";
        createDirs(perUserDir);
        if (chmod(perUserDir.c_str(), 0755) == -1)
            throw SysError(format("could not set permissions on '%1%' to 755")
                           % perUserDir);

        mode_t perm = 01775;

        struct group * gr = getgrnam(settings.buildUsersGroup.c_str());
        if (!gr)
            throw Error(format("the group `%1%' specified in `build-users-group' does not exist")
                % settings.buildUsersGroup);
        else {
            struct stat st;
            if (stat(settings.nixStore.c_str(), &st))
                throw SysError(format("getting attributes of path '%1%'") % settings.nixStore);

            if (st.st_uid != 0 || st.st_gid != gr->gr_gid || (st.st_mode & ~S_IFMT) != perm) {
                if (chown(settings.nixStore.c_str(), 0, gr->gr_gid) == -1)
                    throw SysError(format("changing ownership of path '%1%'") % settings.nixStore);
                if (chmod(settings.nixStore.c_str(), perm) == -1)
                    throw SysError(format("changing permissions on path '%1%'") % settings.nixStore);
            }
        }
    }

    checkStoreNotSymlink();

    /* We can't open a SQLite database if the disk is full.  Since
       this prevents the garbage collector from running when it's most
       needed, we reserve some dummy space that we can free just
       before doing a garbage collection. */
    try {
        Path reservedPath = settings.nixDBPath + "/reserved";
        if (reserveSpace) {
            struct stat st;
            if (stat(reservedPath.c_str(), &st) == -1 ||
                st.st_size != settings.reservedSize)
            {
                AutoCloseFD fd = open(reservedPath.c_str(), O_WRONLY | O_CREAT, 0600);
                int res = -1;
#if HAVE_POSIX_FALLOCATE
                res = posix_fallocate(fd, 0, settings.reservedSize);
#endif
                if (res == -1) {
                    writeFull(fd, string(settings.reservedSize, 'X'));
                    ftruncate(fd, settings.reservedSize);
                }
            }
        }
        else
            deletePath(reservedPath);
    } catch (SysError & e) { /* don't care about errors */
    }

    /* Acquire the big fat lock in shared mode to make sure that no
       schema upgrade is in progress. */
    try {
        Path globalLockPath = settings.nixDBPath + "/big-lock";
        globalLock = openLockFile(globalLockPath.c_str(), true);
    } catch (SysError & e) {
        if (e.errNo != EACCES) throw;
        settings.readOnlyMode = true;
        openDB(false);
        return;
    }

    if (!lockFile(globalLock, ltRead, false)) {
        printMsg(