#lang racket/base

(require racket/file
         racket/list
         racket/path
         racket/string)

(provide bool-value
         int-value
         string-value
         split-addresses
         relpath-string
         flac-path?
         ensure-parent-directory!
         alist-ref/default
         alist-set)

(define (bool-value v [default #f])
  (cond [(boolean? v) v]
        [(number? v) (not (zero? v))]
        [(string? v)
         (define s (string-downcase (string-trim v)))
         (cond [(member s '("#t" "true" "yes" "y" "1" "on")) #t]
               [(member s '("#f" "false" "no" "n" "0" "off" "")) #f]
               [else default])]
        [else default]))

(define (int-value v [default 0])
  (cond [(integer? v) v]
        [(number? v) (inexact->exact (round v))]
        [(string? v) (or (string->number (string-trim v)) default)]
        [else default]))

(define (string-value v [default ""])
  (cond [(string? v) v]
        [(symbol? v) (symbol->string v)]
        [(number? v) (number->string v)]
        [(boolean? v) (if v "#t" "#f")]
        [(not v) default]
        [else (format "~a" v)]))

(define (split-addresses v)
  (define s (string-value v ""))
  (filter (lambda (x) (not (string=? x "")))
          (map string-trim (regexp-split #px"[,;]" s))))

(define (relpath-string base p)
  (path->string (find-relative-path (simple-form-path base) (simple-form-path p))))

(define (flac-path? p)
  (and (file-exists? p)
       (let-values ([(base name dir?) (split-path p)])
         (and (path? name)
              (string-ci=? (bytes->string/utf-8 (or (path-get-extension name) #"")) ".flac")))))

(define (ensure-parent-directory! p)
  (define-values (base name dir?) (split-path p))
  (when (path? base) (make-directory* base)))

(define (alist-ref/default a k [default #f])
  (define e (assoc k a))
  (if e (cdr e) default))

(define (alist-set a k v)
  (cons (cons k v) (filter (lambda (e) (not (equal? (car e) k))) a)))