package common

import (
	"database/sql"
	"strconv"
	"strings"

	qgen "git.tuxpa.in/a/gosora/query_gen"
)

type CustomPageStmts struct {
    update *sql.Stmt
    create *sql.Stmt
}

var customPageStmts CustomPageStmts

func init() {
    DbInits.Add(func(acc *qgen.Accumulator) error {
        customPageStmts = CustomPageStmts{
            update: acc.Update("pages").Set("name=?,title=?,body=?,allowedGroups=?,menuID=?").Where("pid=?").Prepare(),
            create: acc.Insert("pages").Columns("name,title,body,allowedGroups,menuID").Fields("?,?,?,?,?").Prepare(),
        }
        return acc.FirstError()
    })
}

type CustomPage struct {
    ID            int
    Name          string // TODO: Let admins put pages in "virtual subdirectories"
    Title         string
    Body          string
    AllowedGroups []int
    MenuID        int
}

func BlankCustomPage() *CustomPage {
    return new(CustomPage)
}

func (p *CustomPage) AddAllowedGroup(gid int) {
    p.AllowedGroups = append(p.AllowedGroups, gid)
}

func (p *CustomPage) getRawAllowedGroups() (rawAllowedGroups string) {
    for _, group := range p.AllowedGroups {
        rawAllowedGroups += strconv.Itoa(group) + ","
    }
    if len(rawAllowedGroups) > 0 {
        rawAllowedGroups = rawAllowedGroups[:len(rawAllowedGroups)-1]
    }
    return rawAllowedGroups
}

func (p *CustomPage) Commit() error {
    _, err := customPageStmts.update.Exec(p.Name, p.Title, p.Body, p.getRawAllowedGroups(), p.MenuID, p.ID)
    Pages.Reload(p.ID)
    return err
}

func (p *CustomPage) Create() (int, error) {
    res, err := customPageStmts.create.Exec(p.Name, p.Title, p.Body, p.getRawAllowedGroups(), p.MenuID)
    if err != nil {
        return 0, err
    }
    pid64, err := res.LastInsertId()
    return int(pid64), err
}

var Pages PageStore

// Holds the custom pages, but doesn't include the template pages in /pages/ which are a lot more flexible yet harder to use and which are too risky security-wise to make editable in the Control Panel
type PageStore interface {
    Count() (count int)
    Get(id int) (*CustomPage, error)
    GetByName(name string) (*CustomPage, error)
    GetOffset(offset, perPage int) (pages []*CustomPage, err error)
    Reload(id int) error
    Delete(id int) error
}

// TODO: Add a cache to this to save on the queries
type DefaultPageStore struct {
    get       *sql.Stmt
    getByName *sql.Stmt
    getOffset *sql.Stmt
    count     *sql.Stmt
    delete    *sql.Stmt
}

func NewDefaultPageStore(acc *qgen.Accumulator) (*DefaultPageStore, error) {
    pa := "pages"
    allCols := "pid, name, title, body, allowedGroups, menuID"
    return &DefaultPageStore{
        get:       acc.Select(pa).Columns("name, title, body, allowedGroups, menuID").Where("pid=?").Prepare(),
        getByName: acc.Select(pa).Columns(allCols).Where("name=?").Prepare(),
        getOffset: acc.Select(pa).Columns(allCols).Orderby("pid DESC").Limit("?,?").Prepare(),
        count:     acc.Count(pa).Prepare(),
        delete:    acc.Delete(pa).Where("pid=?").Prepare(),
    }, acc.FirstError()
}

func (s *DefaultPageStore) Count() (count int) {
    err := s.count.QueryRow().Scan(&count)
    if err != nil {
        LogError(err)
    }
    return count
}

func (s *DefaultPageStore) parseAllowedGroups(raw string, page *CustomPage) error {
    if raw == "" {
        return nil
    }
    for _, sgroup := range strings.Split(raw, ",") {
        group, err := strconv.Atoi(sgroup)
        if err != nil {
            return err
        }
        page.AddAllowedGroup(group)
    }
    return nil
}

func (s *DefaultPageStore) Get(id int) (*CustomPage, error) {
    p := &CustomPage{ID: id}
    rawAllowedGroups := ""
    err := s.get.QueryRow(id).Scan(&p.Name, &p.Title, &p.Body, &rawAllowedGroups, &p.MenuID)
    if err != nil {
        return nil, err
    }
    return p, s.parseAllowedGroups(rawAllowedGroups, p)
}

func (s *DefaultPageStore) GetByName(name string) (*CustomPage, error) {
    p := BlankCustomPage()
    rawAllowedGroups := ""
    err := s.getByName.QueryRow(name).Scan(&p.ID, &p.Name, &p.Title, &p.Body, &rawAllowedGroups, &p.MenuID)
    if err != nil {
        return nil, err
    }
    return p, s.parseAllowedGroups(rawAllowedGroups, p)
}

func (s *DefaultPageStore) GetOffset(offset, perPage int) (pages []*CustomPage, err error) {
    rows, err := s.getOffset.Query(offset, perPage)
    if err != nil {
        return pages, err
    }
    defer rows.Close()

    for rows.Next() {
        p := &CustomPage{ID: 0}
        rawAllowedGroups := ""
        err := rows.Scan(&p.ID, &p.Name, &p.Title, &p.Body, &rawAllowedGroups, &p.MenuID)
        if err != nil {
            return pages, err
        }
        err = s.parseAllowedGroups(rawAllowedGroups, p)
        if err != nil {
            return pages, err
        }
        pages = append(pages, p)
    }
    return pages, rows.Err()
}

// Always returns nil as there's currently no cache
func (s *DefaultPageStore) Reload(id int) error {
    return nil
}

func (s *DefaultPageStore) Delete(id int) error {
    _, err := s.delete.Exec(id)
    return err
}