#include <stddef.h>

#include <sqlite3.h>

#include "cache.h"
#include "config.h"
#include "uio.h"
#include "ed2k.h"
#include "util.h"

#define sqlite_bind_goto(smt, name, type, ...) { \
        int sb_idx = sqlite3_bind_parameter_index(smt, name); \
        if (sb_idx == 0) { \
            uio_error("Cannot get named parameter for var: %s", name); \
            err = ERR_CACHE_SQLITE; \
            goto fail; \
        } \
        int sb_sret = sqlite3_bind_##type(smt, sb_idx, __VA_ARGS__); \
        if (sb_sret != SQLITE_OK) {\
            uio_error("Cannot bind to statement: %s", sqlite3_errmsg(cache_db));\
            err = ERR_CACHE_SQLITE;\
            goto fail;\
        } \
    }

static sqlite3 *cache_db = NULL;

static const char sql_create_table[] = "CREATE TABLE IF NOT EXISTS mylist ("
        "lid INTEGER NOT NULL PRIMARY KEY,"
        "fname TEXT NOT NULL,"
        "fsize INTEGER NOT NULL,"
        "ed2k TEXT NOT NULL,"
        "UNIQUE (fname, fsize) )";
static const char sql_mylist_add[] = "INSERT INTO mylist "
        "(lid, fname, fsize, ed2k) VALUES "
        //"(?, ?, ?, ?)";
        "(:lid, :fname, :fsize, :ed2k)";
static const char sql_mylist_get[] = "SELECT * FROM mylist WHERE "
        "fsize=:fsize AND fname=:fname";


#if 0
static const char sql_has_tables[] = "SELECT 1 FROM sqlite_master "
        "WHERE type='table' AND tbl_name='mylist'";

/* Return 0 if false, 1 if true, and -1 if error */
static int cache_has_tables()
{
    sqlite3_smt smt;
    int sret;

    sret = sqlite3_prepare_v2(cache_db, sql_has_tables,
            sizeof(sql_has_tables), &smt, NULL);
    if (sret != SQLITE_OK) {
        uio_error("Cannot prepare statement: %s", sqlite3_errmsg(cache_db));
        return -1;
    }

    sqlite3_step(&smt);
    // ehh fuck this, lets just use if not exists
    
    sret = sqlite3_finalize(&smt);
    if (sret != SQLITE_OK)
        uio_debug("sql3_finalize failed: %s", sqlite3_errmsg(cache_db));
}
#endif

/*
 * Create database table(s)
 */
static enum error cache_init_table()
{
    sqlite3_stmt *smt;
    int sret;
    enum error err = NOERR;

    sret = sqlite3_prepare_v2(cache_db, sql_create_table,
            sizeof(sql_create_table), &smt, NULL);
    if (sret != SQLITE_OK) {
        uio_error("Cannot prepare statement: %s", sqlite3_errmsg(cache_db));
        return ERR_CACHE_SQLITE;
    }

    sret = sqlite3_step(smt);
    if (sret != SQLITE_DONE) {
        uio_error("sql3_step is not done: %s", sqlite3_errmsg(cache_db));
        err = ERR_CACHE_SQLITE;
    }
    
    sret = sqlite3_finalize(smt);
    if (sret != SQLITE_OK)
        uio_debug("sql3_finalize failed: %s", sqlite3_errmsg(cache_db));

    return err;
}

enum error cache_init()
{
    char **db_path;
    enum error err;
    int sret;

    err = config_get("cachedb", (void**)&db_path);
    if (err != NOERR) {
        uio_error("Cannot get cache db path from args");
        return err;
    }

    uio_debug("Opening cache db: '%s'", *db_path);
    sret = sqlite3_open(*db_path, &cache_db);
    if (sret != SQLITE_OK) {
        uio_error("Cannot create sqlite3 database: %s", sqlite3_errstr(sret));
        sqlite3_close(cache_db); /* Even if arg is NULL, it's A'OK */
        return ERR_CACHE_SQLITE;
    }
    sqlite3_extended_result_codes(cache_db, 1);

    err = cache_init_table();
    if (err != NOERR)
        goto fail;

    return NOERR;

fail:
    cache_free();
    return err;
}

void cache_free()
{
    sqlite3_close(cache_db);
    uio_debug("Closed cache db");
}

enum error cache_add(uint64_t lid, const char *fname,
        uint64_t fsize, const uint8_t *ed2k)
{
    char ed2k_str[ED2K_HASH_SIZE * 2 + 1];
    sqlite3_stmt *smt;
    int sret;
    enum error err = NOERR;

    sret = sqlite3_prepare_v2(cache_db, sql_mylist_add,
            sizeof(sql_mylist_add), &smt, NULL);
    if (sret != SQLITE_OK) {
        uio_error("Cannot prepare statement: %s", sqlite3_errmsg(cache_db));
        return ERR_CACHE_SQLITE;
    }

    util_byte2hex(ed2k, ED2K_HASH_SIZE, false, ed2k_str);

    sqlite_bind_goto(smt, ":lid", int64, lid);
    sqlite_bind_goto(smt, ":fname", text, fname, -1, SQLITE_STATIC);
    sqlite_bind_goto(smt, ":fsize", int64, fsize);
    sqlite_bind_goto(smt, ":ed2k", text, ed2k_str, -1, SQLITE_STATIC);

    sret = sqlite3_step(smt);
    if (sret != SQLITE_DONE) {
        if (sret == SQLITE_CONSTRAINT_PRIMARYKEY) {
            uio_debug("Attempted to add duplicate entry!");
            err = ERR_CACHE_EXISTS;
        } else if (sret == SQLITE_CONSTRAINT_UNIQUE) {
            uio_debug("An entry with the same name and size already exists!");
            err = ERR_CACHE_NON_UNIQUE;
        } else {
            uio_error("error after sql3_step: %s %d", sqlite3_errmsg(cache_db), sret);
            err = ERR_CACHE_SQLITE;
        }
    }
    
fail:
    sqlite3_finalize(smt);
    return err;
    
}

enum error cache_get(const char *fname, uint64_t fsize,
        struct cache_entry *out_ce)
{
    sqlite3_stmt *smt;
    int sret;
    enum error err = NOERR;

    sret = sqlite3_prepare_v2(cache_db, sql_mylist_get,
            sizeof(sql_mylist_get), &smt, NULL);
    if (sret != SQLITE_OK) {
        uio_error("Cannot prepare statement: %s", sqlite3_errmsg(cache_db));
        return ERR_CACHE_SQLITE;
    }

    sqlite_bind_goto(smt, ":fname", text, fname, -1, SQLITE_STATIC);
    sqlite_bind_goto(smt, ":fsize", int64, fsize);

    sret = sqlite3_step(smt);
    if (sret == SQLITE_DONE) {
        uio_debug("Cache entry with size (%lu) and name (%s) not found", fsize, fname);
        err = ERR_CACHE_NO_EXISTS;
    } else if (sret == SQLITE_ROW) {
        uio_debug("Found Cache entry with size (%lu) and name (%s)", fsize, fname);
    } else {
        uio_error("sqlite_step failed: %s", sqlite3_errmsg(cache_db));
        err = ERR_CACHE_SQLITE;
    }
    
fail:
    sqlite3_finalize(smt);
    return err;
}