#lang racket

(require json)
(require web-server/servlet)
(require web-server/servlet-env)
(require web-server/templates)

(require "blacklist.rkt")

(define (member-match? itm lst)
  (ormap (lambda (i) (regexp-match? (regexp i) itm)) lst))

(define-values (dispatch generate-url)
  (dispatch-rules
    [("") do-index]
    [("search") do-search]
    ))

(define (do-head title)
  (include-template "templates/head.html"))

(define (do-footer)
  (include-template "templates/footer.html"))

(define (do-index req)
  (http-response (string-append
		   (do-head "Web Search")
		   (include-template "templates/index.html")
		   (do-footer))))

(define (search query pageno)
  (define engine (string->url
		   (string-append
		     (getenv "SEARX_INSTANCE")
		     "/search?format=json&q="
		     query
		     "&pageno="
		     pageno
		     )))
  (define response (get-pure-port engine))
  (define json-raw (port->string response))
  (close-input-port response)
  (with-input-from-string json-raw (lambda () (read-json))))

(define (http-response content)
  (response/full
    200
    #"OK"
    (current-seconds)
    TEXT/HTML-MIME-TYPE
    '()
    (list
      (string->bytes/utf-8 content))))

(define (do-search req)
  (define binds (request-bindings req))
  (define query (if (exists-binding? 'q binds)
		  (extract-binding/single 'q binds)
		  ""))

  (if (non-empty-string? query)
    (let ()
      (define pageno (if (exists-binding? 'pageno binds)
		       (extract-binding/single 'pageno binds)
		       "1"))
      (define results
	(foldr cons '()
	       (filter hash?
		       (map (lambda (i)
			      (define result-host
				(url-host (string->url
					    (hash-ref i 'url ""))))
			      (define result-url (hash-ref i 'url ""))
			      (define result-title (hash-ref i 'title ""))
			      (define result-content (hash-ref i 'content ""))
			      (define ht (make-hash))
			      (unless (member-match? result-host blacklist)
				(let ()
				  (hash-set! ht "title" result-title)
				  (hash-set! ht "url" result-url)
				  (hash-set! ht "content" result-content)
				  )
				ht
				))
			    (hash-ref (search query pageno) 'results)))))
      (http-response (string-append
		       (do-head (string-append query " | Web Search"))
		       (include-template "templates/search.html")
		       (do-footer))))
    (redirect-to "/")))

(serve/servlet dispatch
	       #:command-line? #t
	       #:servlet-regexp #rx""
	       #:extra-files-paths (list (build-path "./static")))