(import-macros {: map : reduce : filter} :lib.macro)

(tset package :path (.. package.path ";./vendor/lpeglj/?.lua"))

(local io (require :io))
(local math (require :math))
(local fennel (require :vendor.fennel))
(local html (require :vendor.html))
(local json (require :vendor.json))
(local array (require :lib.array))
(local str (require :lib.string))
(local texts (require :texts))
(local fs (require :lib.fs))
(local spellfix (require :lib.spellfix))
(local cache (require :lib.cache))
(local {: must : measure} (require :lib.utils))

(when _G.unpack
 (tset table :unpack _G.unpack))

(local db (must (luna.db.open "file:var/db.sqlite?_journal=WAL&_sync=NORMAL")))

(local query-synonyms {
  "шэн" "шен"
  "шен" "шэн"
  "дянь" "дань"
  "дань" "дянь"
  "чжень" "чжэнь"
  "чжэнь" "чжень"
  "хун" "цун"
  "цун" "хун"
  "доска" "чабань"
  "лунцзин" "лун цзин"
  "лун цзин" "лунцзин"
  "чахай" "сливник"
  "сливник" "чахай"
  "чабань" "доска"
  "термос" "бутылка"
  "бутылка" "термос"})

(fn unescape [s]
  (assert (= (type s) :string) "s must be string")
  (pick-values 1
   (-> s
    (string.gsub "&lt;" "<")
    (string.gsub "&gt;" ">")
    (string.gsub "&quot;" "\"")
    (string.gsub "&amp;" "&"))))

(fn category-menu-path [category]
  (. {"Красный чай" "red-tea"
      "Шен пуэр" "sheng-puer"
      "Шу пуэр" "shou-puer"
      "Улун" "oolong"
      "Зеленый чай" "green-tea"
      "Белый чай" "white-tea"
      "Желтый чай" "yellow-tea"
      "Посуда" "teaware"} category))

(fn get-query-string [query key]
  (if (and query
          (. query key)
          (. query key 1)
          (< 0 (# (. query key 1))))
    (. query key 1)
    nil))

(fn get-query-number [query key]
  (if (and query
          (. query key)
          (. query key 1)
          (< 0 (# (. query key 1))))
    (tonumber (. query key 1))
    nil))

(fn serialize-query [query]
  (local flattened-object
    (collect [k v (pairs query)]
      (values k (array.join (map (fn [_ vv] (.. k "=" vv)) v) "&"))))
  (array.join (array.list flattened-object) "&"))

(fn collect-form [params category]
  {:query (str.trim (or (get-query-string params "query") ""))
   :tags (filter #(~= "" $2) (or params.tags [category]))
   :site (str.trim (or (get-query-string params "site") ""))
   :sort (str.trim (or (get-query-string params "sort") ""))
   :min-price (get-query-number params "min-price")
   :max-price (get-query-number params "max-price")
   :price-per (= "on" (get-query-string params "price-per"))})

(fn form-empty? [form]
  (and
   (= "" form.query)
   (= (# form.tags) 0)
   (= "" form.site)
   (not form.min-price)
   (not form.max-price)
   ;; price-per and sort are intentionally left out since they must not
   ;; trigger search by itself
   ))

(fn form->path [page form]
  (.. "?page=" (tostring page)
      (if (not (str.empty? form.query))
        (.. "&query=" form.query)
        "")
      (if (< 0 (# form.tags))
        (.. "&"
            (array.join
              (array.flatten
                (map (fn [_ tag] (.. "tags=" tag))
                     form.tags))
              "&"))
        "")
      (if (not (str.empty? form.site))
        (.. "&site=" form.site)
        "")
      (if (and form.min-price (< 0 form.min-price))
        (.. "&min-price=" (tostring form.min-price))
        "")
      (if (and form.max-price (< 0 form.max-price))
        (.. "&max-price=" (tostring form.max-price))
        "")
      (if form.price-per
        "&price-per=on"
        "")
      (if form.sort
        (.. "&sort=" form.sort)
        "")))

(fn teas-of-the-day [limit]
  (assert (< 0 limit) "limit must be > 0")
  (local the-number (* (tonumber (os.date "%Y%m%d")) limit))
  (local total
    (. (must (luna.db.query db
               "SELECT count(ROWID)
                FROM (
                 SELECT products.ROWID
                 FROM products
                 INNER JOIN product_tags ON product_tags.product = products.url
                 WHERE archived = false
                 AND product_tags.tag IN ('Красный чай', 'Улун', 'Шен пуэр',
                                          'Шу пуэр', 'Зеленый чай', 'Белый чай',
                                          'Желтый чай')
                 GROUP BY products.url)" []))
       1 1))
  (must
    (luna.db.query*
      db
      "SELECT products.site,
              products.title,
              products.description,
              products.image,
              products.url,
              products.price,
              products.weight,
              products.price_per AS \"price-per\"
      FROM products
      INNER JOIN product_tags ON product_tags.product = products.url
      WHERE products.archived = false
      AND product_tags.tag IN ('Красный чай', 'Улун', 'Шен пуэр', 'Шу пуэр',
                               'Зеленый чай', 'Белый чай', 'Желтый чай')
      GROUP BY products.url
      ORDER BY ROW_NUMBER() over (PARTITION BY site ORDER BY products.ROWID)
      LIMIT ?
      OFFSET ?"
      [limit (% the-number (- total limit))])))

(fn all-tags []
  (map
    (fn [_ v] (. v 1))
    (must
     (luna.db.query
      db
      "SELECT DISTINCT tags.title FROM tags
       INNER JOIN product_tags ON product_tags.tag = tags.title
       ORDER BY creation_time"
      []))))

(fn query-products [{: query : tags : min-price : max-price : price-per : site : sort} page]
  (local tags (or tags []))

  (var where-conds [])
  (var query-args [])

  ;; create WHERE clause from dynamic form parameters
  (when (< 0 (# tags))
    (each [_ tag (pairs tags)]
      (table.insert where-conds "product_tags.tag = ?")
      (table.insert query-args tag)))
  (when (and query (< 0 (# query)))
    (table.insert where-conds "search.title MATCH ?")
    (table.insert query-args
      (array.join
        (map (fn [_ q]
               (local lower-q (must (luna.utf8.lower q)))
               (if (. query-synonyms lower-q)
                 (.. "(" q "* OR " (. query-synonyms lower-q) "*)")
                 (.. q "*")))
             (str.split query " "))
        " AND ")))
  (when (not (str.empty? site))
    (table.insert where-conds "products.site = ?")
    (table.insert query-args site))
  (when (and min-price (< 0 min-price))
    (if price-per
      (table.insert where-conds "products.price_per >= ?")
      (table.insert where-conds "products.price >= ?"))
    (table.insert query-args min-price))
  (when (and max-price (< 0 max-price))
    (if price-per
      (table.insert where-conds "products.price_per <= ?")
      (table.insert where-conds "products.price <= ?"))
    (table.insert query-args max-price))
  (local where-sql
    (if (< 0 (# where-conds))
      (.. "AND   " (array.join where-conds "\nAND "))
      ""))

  ;; create SORT clause from dynamic form parameters
  (var sort-criteria [])
  (when sort
    (if (= sort "cheap-first")
      (table.insert sort-criteria
        ;; multiple price by 100 if we only know a price for 1 gram
        "CASE WHEN products.weight = 1 THEN products.price * 100
              ELSE products.price
         END ASC")
     (= sort "expensive-first")
      (table.insert sort-criteria
        ;; multiple price by 100 if we only know a price for 1 gram
        "CASE WHEN products.weight = 1 THEN products.price * 100
              ELSE products.price
         END DESC")))
  (local sort-sql
    (if (< 0 (# sort-criteria))
      (.. (array.join sort-criteria ",\n") ",")
      ""))

  (local total
   (must
    (luna.db.query
     db
     (string.format
       "SELECT count(ROWID)
        FROM (
         SELECT products.ROWID
         FROM search
         INNER JOIN products ON search.fid = products.url
         LEFT JOIN product_tags ON product_tags.product = search.fid
         WHERE search.`table` = 'products'
         AND   products.archived = false
         %s
         GROUP BY products.url)" where-sql)
     query-args)))

  {:results
   (must
    (luna.db.query*
     db
     (string.format
       "SELECT products.title,
               products.site,
               products.description,
               products.image,
               products.url,
               products.price,
               products.weight,
               products.price_per AS \"price-per\"
       FROM search
       INNER JOIN products ON search.fid = products.url
       LEFT JOIN product_tags ON product_tags.product = products.url
       WHERE search.`table` = 'products'
       AND   products.archived = false
       %s
       GROUP BY products.url
       ORDER BY %s
                ROW_NUMBER() over (PARTITION BY products.site ORDER BY products.ROWID),
                rank
       LIMIT 48 OFFSET ?" where-sql sort-sql)
     (array.concat query-args [(* (- page 1) 48)])))
   :total (if (< 0 (# total))
           (. total 1 1)
           0)})

(fn site-name-template [name]
  (local module (require (.. "parser." name)))
  [:a {:class "site-icon" :href (.. module.url "?from=everytea.ru")}
   [:img {:src (.. "/static/" name ".png") :alt (.. "Логотип " module.title)}]
   module.title])

(fn item-template [product]
  (local link (.. product.url "?from=everytea.ru"))
  [:div {:class "tile"}
   [:a {:href link :class "img-link" :rel "nofollow"}
    [:img {:class "img" :src product.image :title product.title
           :alt product.title} ""]]
   (site-name-template product.site)
   [:a {:href link :style "text-decoration: none;" :rel "nofollow"}
    [:NO-ESCAPE (.. "<h2>" (unescape product.title) "</h2>")]]
   [:div {:class "price"}
    (if product.price (.. (str.format-price product.price) "₽") "")
    (if (< 0 product.weight)
      [:NO-ESCAPE (.. "за&nbsp;" product.weight "&nbsp;гр.")]
      "")
    (if (and (< 1 product.weight)
             product.price-per
             (< 0 product.price-per))
     [:NO-ESCAPE (.. "<br> (" (str.format-price product.price-per)
                     "₽ за&nbsp;1&nbsp;гр.)")]
     "")]])

(fn paginator-template [form page limit total max-numbers]
  (local last-page (math.ceil (/ total limit)))
  (local radius (math.floor (/ (- max-numbers 4) 2)))
  (local number-items
    (if (<= last-page max-numbers)
      (faccumulate [res [:span {}] i 1 last-page]
       (do
         (table.insert
           res [:a {:href (form->path i form)
                    :class (if (= page i) "paginator-active" "")}
                (tostring i)])
         res))
      [:span {}
       (table.unpack
        (array.concat
          (if (< (+ 1 radius) page)
            [[:a {:href (form->path 1 form)} "1"]
             (if (< (+ 2 radius) page) "…" "")]
            [])
          (faccumulate [res [] i (math.max 1 (- page radius))
                                 (math.min last-page (+ page radius))]
           (do
             (table.insert
               res [:a {:href (form->path i form)
                        :class (if (= page i) "paginator-active" "")}
                    (tostring i)])
             res))
          (if (< radius (- last-page page))
            [(if (< (+ 1 radius) (- last-page page)) "…" "")
             [:a {:href (form->path last-page form)} (tostring last-page)]]
            [])))]))

  (if (< limit total)
    [:div {:class "paginator"}
     [:div {:class "paginator-numbers"} number-items]
     [:div {} "Всего: " [:strong {} (string.format "%d" total)]]]
    ""))

(fn menu-template [path extra-class]
  (local item
    (fn [item-path title]
      [:a {:href item-path
           :class (if (= path item-path) "active" "")}
          title]))
  [:nav {:class (.. "menu" (if (str.empty? extra-class)
                             ""
                             (.. " " extra-class)))}
        (item "/red-tea" "Красный чай")
        (item "/sheng-puer" "Шен пуэр")
        (item "/shou-puer" "Шу пуэр")
        (item "/oolong" "Улун")
        (item "/green-tea" "Зеленый чай")
        (item "/white-tea" "Белый чай")
        (item "/yellow-tea" "Желтый чай")
        (item "/teaware" "Посуда")])

(fn aside-template [form path paginator]
  [:aside {:class "aside"}
   [:div {:class "aside-content"}
    (if (not (form-empty? form))
      [:a {:href "/" :style "display: block;"}
       [:img {:class "logo" :src "/static/logo.svg"
              :alt "Логотип everytea.ru" :title "Логотип everytea.ru"}]]
       [:img {:class "logo" :src "/static/logo.svg"
              :alt "Логотип everytea.ru" :title "Логотип everytea.ru"}])
    (menu-template path "menu-mobile")
    [:form {:class "form"}
     [:input {:type :search :name "query" :value form.query
              :autofocus true :placeholder "Поисковый запрос"}]
     [:div {}
      [:select {:name "tags"}
        [:option {:value ""} "~ Тег ~"]
        (table.unpack
          (map
            (fn [_ tag]
                [:option {:value tag
                          :selected (if (array.contains form.tags tag)
                                        "selected" nil)}
                tag])
            (all-tags)))]]
     [:div {:class "form-price"}
      [:input {:type :number :name :min-price :min "1"
               :placeholder "От ₽" :value (tostring form.min-price)}]
      [:input {:type :number :name :max-price :min "1"
               :placeholder "До ₽" :value (tostring form.max-price)}]]
     [:div {:class "form-price-per"}
      [:input {:type :checkbox :id "price-per" :name "price-per"
               :checked (if form.price-per "checked" nil)}]
      [:label {:for "price-per"} "цена за грамм"]]
     [:div {}
      [:select {:name "site"}
       [:option {:value ""} "~ Сайт ~"]
        (table.unpack
          (map
            (fn [_ val]
              [:option {:value val
                        :selected (if (= form.site val) "selected" nil)}
                       (. (require (.. "parser." val)) :title)])
            [:ozchai :clubcha :ipuer :artoftea :chaekshop]))]]
     [:div {}
      [:select {:name "sort"}
       [:option {:value ""} "~ Порядок ~"]
       [:option {:value "cheap-first"
                 :selected (if (= form.sort "cheap-first") "selected" nil)}
         "Сначала дешевле"]
       [:option {:value "expensive-first"
                 :selected (if (= form.sort "expensive-first") "selected" nil)}
         "Сначала дороже"]]]
     [:button {:type :submit} "Искать"]]
    paginator]])

(fn base-template [form path page total items text]
  (local menu-path
   (if (and form.tags (< 0 (# form.tags)))
    (category-menu-path (. form.tags 1))
    nil))
  (local spellfix-suggestion
    (if (and (not (str.empty? form.query)) items (= 0 (# items)))
     (cache.wrap
       db (.. "spellfix:" form.query)
       #(spellfix.guess form.query))
     nil))

  [:html {:lang "ru-RU"}
   [:head {}
    [:meta {:charset "utf-8"}]
    [:meta {:name "viewport" :content "width=device-width,initial-scale=1,minimum-scale=1.0,maximum-scale=5.0"}]
    ;; inline styles so the page loads faster
    [:style {} [:NO-ESCAPE (fs.read-file "static/style.css")]]
    [:link {:rel "icon" :href "/static/favicon.png"}]
    [:link {:rel "preload" :fetchpriority "high" :as "image"
            :href "/static/logo-hor.svg" :type "image/svg+xml"}]
    [:title {} (if (str.empty? form.query)
                 texts.meta-title
                 (.. form.query " | " texts.meta-title))]
    [:meta {:name "description" :content texts.meta-description}]]
   [:body {}
    [:div {:class "container"}
     [:div {:class "content"}
      (aside-template form path (paginator-template form page 48 total 7))
      [:main {}
       (menu-template path)
       [:article {:class "description"}
        (if (. form.tags 1)
         [:h1 {} (. form.tags 1)]
         "")
        (if (and menu-path (. texts (.. menu-path "-description")))
          [:div {:class "description-text text"}
           [:NO-ESCAPE (. texts (.. menu-path "-description"))]]
          "")]
       (if text
         [:p {:class "text"} text]
        (< 0 (# items))
         [:div {:class "list"}
          (table.unpack (map #(item-template $2) items))]
        [:p {:class "text"}
         (if spellfix-suggestion
          [:NO-ESCAPE
            (string.format texts.no-results-with-suggestion
                           spellfix-suggestion
                           spellfix-suggestion)]
          [:NO-ESCAPE texts.no-results])])
       [:div {} (paginator-template form page 48 total 17)]
       [:footer {}
        [:small {:class "text"} [:NO-ESCAPE texts.footer-text]]]]]]]])

(fn root-handler [{: path : query}]
  (local cache-key (.. "page:" path "?" (serialize-query query)))
  (local cached (cache.get db cache-key))
  (if cached
    (values 200 {:content-type "text/html"} cached)
    (do
      (fn respond [query category]
       (let [headers {:content-type "text/html"}
             page (or (get-query-number query "page") 1)
             form (collect-form query category)
             {: results : total}
               (if (not (form-empty? form))
                 (query-products form page)
                 {:total 10 :results (teas-of-the-day 10)})]
         (values
           200 headers
           (cache.set db cache-key
            (.. "<!DOCTYPE html>\n"
                (html.render
                 (base-template form path page total results)
                 true))))))

      (match (str.split path "/")
        ["red-tea"] (respond query "Красный чай")
        ["sheng-puer"] (respond query "Шен пуэр")
        ["shou-puer"] (respond query "Шу пуэр")
        ["oolong"] (respond query "Улун")
        ["green-tea"] (respond query "Зеленый чай")
        ["white-tea"] (respond query "Белый чай")
        ["yellow-tea"] (respond query "Желтый чай")
        ["teaware"] (respond query "Посуда")
        (where t (= 0 (# t))) (respond query)
        _ (values
           404 {:content-type "text/html"}
           (.. "<!DOCTYPE html>\n"
               (html.render
                (base-template
                 (collect-form query nil)
                  "" 1 0 [] "Страница не найдена!")
                 true)))))))

(fn robots-handler []
  (values 200 {:content-type "text/plain"} "User-agent: *\nAllow: /"))

(must (luna.router.route "GET /" root-handler))
(must (luna.router.route "GET /robots.txt" robots-handler))
(must (luna.router.static "GET /static/" "static/"))