#ifndef FILE_TREE_INCLUDED
#define FILE_TREE_INCLUDED

#include "basic.h"

#define NO_GENERATION ((uint64_t) 0)

enum {
    FILETREE_NOMEM   = -1,
    FILETREE_NOENT   = -2,
    FILETREE_NOTDIR  = -3,
    FILETREE_ISDIR   = -4,
    FILETREE_EXISTS  = -5,
    FILETREE_BADPATH = -6,
    FILETREE_BADOP   = -7,
    FILETREE_BADGEN  = -8,
};

typedef struct Entity Entity;

typedef struct {
    uint64_t chunk_size; // TODO: this should be an u32
    uint64_t num_chunks; // TODO: and this too
    uint64_t file_size;  // Offset of last byte written + 1
    SHA256 *chunks;
} File;

typedef struct {
    uint64_t max_children;
    uint64_t num_children;
    Entity *children;
} Dir;

struct Entity {
    uint64_t gen;
    char name[1<<8];
    uint16_t name_len;
    bool is_dir;
    union {
        Dir  d;
        File f;
    };
};

typedef struct {
    Entity root;
    uint64_t next_gen;
} FileTree;

typedef struct {
    char name[1<<8];
    int  name_len;
    bool is_dir;
    uint64_t gen;
} ListItem;

#define MAX_COMPS 32

int file_tree_init(FileTree *ft);

void file_tree_free(FileTree *ft);

bool file_tree_uses_hash(FileTree *ft, SHA256 hash);

int file_tree_list(FileTree *ft, string path,
    ListItem *items, int max_items, uint64_t *gen);

int file_tree_create_entity(FileTree *ft, string path,
    bool is_dir, uint64_t chunk_size, uint64_t *gen);

int file_tree_delete_entity(FileTree *ft, string path,
    uint64_t expected_gen);

int file_tree_write(FileTree *ft, string path,
    uint64_t off, uint64_t len, uint32_t num_chunks,
    uint64_t expect_gen,
    uint64_t *new_gen,
    SHA256 *hashes,
    SHA256 *removed_hashes,
    int *num_removed,
    bool truncate_after);

int file_tree_read(FileTree *ft, string path,
    uint64_t off, uint64_t len, uint64_t *gen, uint64_t *chunk_size,
    SHA256 *hashes, int max_hashes, uint64_t *actual_bytes);

string file_tree_strerror(int code);

int file_tree_serialize(FileTree *ft, int (*flush_fn)(char*,int,void*), void *flush_data);

int file_tree_deserialize(FileTree *ft, int (*read_fn)(char*,int,void*), void *read_data);

#endif // FILE_TREE_INCLUDED