/*	$Id$ */
/*
 * Copyright (c) 2016 Kristaps Dzonsons <kristaps@bsd.lv>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#include <kcgi.h>
#include <kcgijson.h>
#include "ksql.h"

#include "extern.h"

#define STMT_PAGE " LIMIT ? OFFSET ?"
#define STMT_AUTHORS0 "SELECT authors.id, authors.name, count(book) as count FROM authors, books_authors_link "\
    "WHERE authors.id = books_authors_link.author GROUP BY author "
#define STMT_AUTHORS_SEARCH "SELECT id, name FROM authors WHERE "
#define STMT_SEARCH_TERM " sort like ? "
#define STMT_BOOL_AND " AND " 
#define STMT_BOOL_OR  " OR "
#define STMT_SEARCH_ORDER " ORDER BY sort"

enum    stmt {
  STMT_AUTHORS_ID_ASC,
  STMT_AUTHORS_ID_DESC,
  STMT_AUTHORS_NAME_ASC,
  STMT_AUTHORS_NAME_DESC,
  STMT_AUTHOR_BOOKS,
  STMT_AUTHORS_AUTHORS,
  STMT_AUTHOR,
  STMT__MAX
};

static const char *const stmts[STMT__MAX] = {
  /* STMT_AUTHORS_ID_ASC */
  STMT_AUTHORS0 "ORDER BY authors.id " STMT_PAGE,
  /* STMT_AUTHORS_ID_DESC */
  STMT_AUTHORS0 "ORDER BY authors.id DESC " STMT_PAGE,
  /* STMT_AUTHORS_NAME_ASC */
  STMT_AUTHORS0 "ORDER BY authors.sort " STMT_PAGE,
  /* STMT_AUTHORS_NAME_DESC */
  STMT_AUTHORS0 "ORDER BY authors.sort DESC " STMT_PAGE,
  /* STMT_AUTHOR_BOOKS */
  "SELECT books.id AS id,title,series_index,name as series_name,series.id AS series_id \
    FROM books LEFT OUTER JOIN books_series_link ON books.id = books_series_link.book \
    LEFT OUTER JOIN series ON series.id = books_series_link.series \
    LEFT OUTER JOIN books_authors_link ON books.id = books_authors_link.book \
    WHERE books_authors_link.author = ? ORDER BY id",
  /* STMT_AUTHORS_AUTHORS */
  "SELECT authors.id, authors.name, books_authors_link.book as book \
    FROM authors, books_authors_link WHERE books_authors_link.author = authors.id \
    AND books_authors_link.book IN ( SELECT books.id FROM books LEFT OUTER JOIN books_authors_link \
        ON books.id = books_authors_link.book WHERE books_authors_link.author = ? ORDER BY books.id)",
  /* STMT_AUTHOR */
  "SELECT name FROM authors WHERE id = ?",
};

void
db_author_unfill(Author *p)
{
  if (NULL == p)
    return;
  free(p->name);
}

void
db_author_adv_free(AuthorAdv *p)
{
  db_author_unfill(&p->a);
  free(p);
}

void
db_author_free(Author *p) {
  db_author_unfill(p);
  free(p);
}

static int
query_authors(const char* sort, const char *order)
{
  int query = STMT_AUTHORS_ID_ASC;
  if (NULL != sort && 0 == strcmp(sort, "name")) {
    query = STMT_AUTHORS_NAME_ASC;
    if (NULL != order && 0 == strcmp(order, "desc"))
      query++;
  } else {
    if (NULL == order || 0 == strcmp(order, "desc"))
      query++;
  }
  return query;
}

AuthorFull *
db_author_load(struct kreq *r, int64_t id)
{
  struct ksqlstmt *stmt;
  struct bookauth *item = NULL;
  struct bookauth *p = NULL;
  int books = 0;
  BookAdv *b;

  AuthorFull *a = kcalloc(1, sizeof(AuthorFull));
  a->a.id = id;

  ksql_stmt_alloc(r->arg, &stmt, 
            stmts[STMT_AUTHOR_BOOKS], 
            STMT_AUTHOR_BOOKS);
  ksql_bind_int(stmt, 0, id);
  while (KSQL_ROW == ksql_stmt_step(stmt)) {
    books++;
    b = kcalloc(1, sizeof(BookAdv));
    b->asize = 0;
    b->tsize = 0;
    db_book_fill(&b->b, stmt);
    item = kcalloc(1, sizeof(struct bookauth));
    item->b = b;
    item->a = &a->a;

    item->p = p;
    p = item;
  }
  ksql_stmt_free(stmt);

  a->bsize = books;
  if (books>0) {
    a->books = kcalloc(books, sizeof(BookAdv));
    while (NULL != p && books > 0) {
      a->books[--books] = p->b;
      item = p;
      p = p->p;
      free(item);
    }

    ksql_stmt_alloc(r->arg, &stmt, 
        stmts[STMT_AUTHORS_AUTHORS], 
        STMT_AUTHORS_AUTHORS);
    ksql_bind_int(stmt, 0, id);
    p = db_load_books_authors(a->books, a->bsize, stmt);
    ksql_stmt_free(stmt);
    db_assign_book_authors(p);
    // get name from 1st book
    for (size_t i=0; i<a->books[0]->asize; i++) {
      if (a->a.id == a->books[0]->a[i]->id)
        a->a.name = a->books[0]->a[i]->name;
    }
  } else {
    // no books, get name
    ksql_stmt_alloc(r->arg, &stmt, 
        stmts[STMT_AUTHOR], 
        STMT_AUTHOR);
    ksql_bind_int(stmt, 0, id);
    if (KSQL_ROW == ksql_stmt_step(stmt))
      a->a.name = kstrdup(ksql_stmt_str(stmt, 0));
    else
      a = NULL;
    ksql_stmt_free(stmt);
  }
  return a;
}

int
db_authors_load(struct kreq *r, AuthorAdv **authors, const char *sort, const char *order, int limit, int offset)
{
  if (limit < 0 || offset < 0) {
    return 0;
  }
  struct ksqlstmt *stmt;
  int count = 0;

  int query = query_authors(sort, order);
  ksql_stmt_alloc(r->arg, &stmt, 
            stmts[query], 
            query);
  ksql_bind_int(stmt, 0, limit);
  ksql_bind_int(stmt, 1, offset);
  while (KSQL_ROW == ksql_stmt_step(stmt)) {
    authors[count] = kcalloc(1, sizeof(AuthorAdv));
    authors[count]->a.id = ksql_stmt_int(stmt, 0);
    authors[count]->a.name = kstrdup(ksql_stmt_str(stmt, 1));
    authors[count]->count = ksql_stmt_int(stmt, 2);
    count++;
  }
  ksql_stmt_free(stmt);

  return count;
}

int
db_authors_search(struct kreq *r, int limit, Author** authors, const char **terms, int num, int all)
{
  if (limit < 0) {
    return 0;
  }
  struct ksqlstmt *stmt;
  int i, count = 0;

  size_t sqlsz = sizeof(STMT_AUTHORS_SEARCH)
    + num * sizeof(STMT_SEARCH_TERM)
    + (num-1) * sizeof(STMT_BOOL_AND)
    + sizeof(STMT_SEARCH_ORDER);
  char *sql = kcalloc(sqlsz, sizeof(char));
  strlcat(sql, STMT_AUTHORS_SEARCH, sqlsz);
  for (i=0; i<num; i++) {
    strlcat(sql, STMT_SEARCH_TERM, sqlsz);
    if (i<num-1 && all)
      strlcat(sql, STMT_BOOL_AND, sqlsz);
    if (i<num-1 && !all)
      strlcat(sql, STMT_BOOL_OR, sqlsz);
  }
  strlcat(sql, STMT_SEARCH_ORDER, sqlsz);

  debug(r, "SQL: %s", sql);
  ksql_stmt_alloc(r->arg, &stmt, sql, 0);
  for (i=0; i<num; i++) {
    size_t sz = 3 + strlen(terms[i]);
    char *term = kcalloc(sz, sizeof(char));
    strlcat(term, "\%", sz);
    strlcat(term, terms[i], sz);
    strlcat(term, "\%", sz);
    ksql_bind_str(stmt, i, term);
  }
  while (KSQL_ROW == ksql_stmt_step(stmt)) {
    if (count < limit) {
      authors[count] = kcalloc(1, sizeof(Author));
      authors[count]->id = ksql_stmt_int(stmt, 0);
      authors[count]->name = kstrdup(ksql_stmt_str(stmt, 1));
    }
    count++;
  }
  ksql_stmt_free(stmt);

  return count;
}