/* -----------------------------------------------------------------------------
Copyright 2020-2021,2023 Kevin P. Barry

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
----------------------------------------------------------------------------- */

// Author: Kevin P. Barry [ta0kira@gmail.com]

$TestsOnly$

define Testing {
  checkEquals (x, y) { $NoTrace$
    Bool failed <- false
    if (`present` x && `present` y && !#x.equals(`require` x, `require` y)) {
      failed <- true
    } elif (`present` x != `present` y) {
      failed <- true
    }
    if (failed) {
      fail(String.builder()
          .append(autoFormat(x))
          .append(" is not equal to ")
          .append(autoFormat(y))
          .build())
    }
  }

  checkNotEquals (x, y) { $NoTrace$
    Bool failed <- false
    if (`present` x && `present` y && #x.equals(`require` x, `require` y)) {
      failed <- true
    } elif (! `present` x &&  ! `present` y) {
      failed <- true
    }
    if (failed) {
      fail(String.builder()
          .append(autoFormat(x))
          .append(" is equal to ")
          .append(autoFormat(y))
          .build())
    }
  }

  checkEmpty (x) { $NoTrace$
    if (present(x)) {
      fail(String.builder()
          .append(autoFormat(x))
          .append(" is not empty")
          .build())
    }
  }

  checkPresent (x) { $NoTrace$
    if (!present(x)) {
      fail(String.builder()
          .append("expected non-empty value")
          .build())
    }
  }

  checkTrue (x) { $NoTrace$
    if (! `present` x) {
      fail("expected true but got empty")
    }
    if (!require(x).asBool()) {
      fail("expected true but got false")
    }
  }

  checkFalse (x) { $NoTrace$
    if (! `present` x) {
      fail("expected false but got empty")
    }
    if (require(x).asBool()) {
      fail("expected false but got true")
    }
  }

  checkBetween (x, l, h) { $NoTrace$
    if (!lessEquals(l, h)) {
      fail(String.builder()
          .append("Upper limit ")
          .append(autoFormat(l))
          .append(" is not at or above lower limit ")
          .append(autoFormat(h))
          .build())
    }
    Bool failed <- false
    if (! `present` x) {
      failed <- true
    } elif (!lessEquals(l, `require` x) || !lessEquals(`require` x, h)) {
      failed <- true
    }
    if (failed) {
      fail(String.builder()
          .append(autoFormat(x))
          .append(" is not between ")
          .append(autoFormat(l))
          .append(" and ")
          .append(autoFormat(h))
          .build())
    }
  }

  checkGreaterThan (x, l) { $NoTrace$
    Bool failed <- false
    if (! `present` x) {
      failed <- true
    } elif (!lessEquals(l, `require` x)) {
      failed <- true
    }
    if (failed) {
      fail(String.builder()
          .append(autoFormat(x))
          .append(" is not greater than ")
          .append(autoFormat(l))
          .build())
    }
  }

  checkLessThan (x, h) { $NoTrace$
    Bool failed <- false
    if (! `present` x) {
      failed <- true
    } elif (!lessEquals(`require` x, h)) {
      failed <- true
    }
    if (failed) {
      fail(String.builder()
          .append(autoFormat(x))
          .append(" is not less than ")
          .append(autoFormat(h))
          .build())
    }
  }

  @type autoFormat<#x> (optional #x) -> (Formatted)
  autoFormat (x) {
    if (! `present` x) {
      return "empty"
    }
    scoped {
      optional Formatted formatted <- reduce<#x, Formatted>(x)
    } in if (`present` formatted) {
      return `require` formatted
    } else {
      return "(unknown)"
    }
  }

  @type lessEquals<#x>
    #x defines Equals<#x>
    #x defines LessThan<#x>
  (#x, #x) -> (Bool)
  lessEquals (x, y) { $NoTrace$
    // Using !#x.lessThan(y, x) wouldn't account for NaNs.
    return #x.lessThan(x, y) || #x.equals(x, y)
  }
}