(ns clojure-sql.dsl-test
  (:refer-clojure :exclude [sort-by])
  (:require [clojure-sql.dsl :refer :all]
            [midje.sweet :refer :all]))

(fact "Table creates basic queries on tables"

  (table ..name..)
  => {:tables {..name.. ..name..}}
  ;(provided (keyword? ..name..) => true)

  (table {..name.. ..alias..})
  => {:tables {..alias.. ..name..}}

  (table {..name.. ..alias.., ..name2.. ..alias2..})
  => {:tables {..alias.. ..name..,
               ..alias2.. ..name2..}})


(fact "Project restricts (and/or adds) fields of a query"
  
  (prerequisites (keyword? ..table-alias..) => true
                 (keyword? ..table..) => true
                 (keyword? ..field..) => true
                 (keyword? ..field-alias..) => true
                 (keyword? ..field2..) => true
                 (keyword? ..field2-alias..) => true)

  (fact "projecting onto a single field from one table"
    (->  (table {..table.. ..table-alias..})
         (project [..field..]))
    => {:tables {..table-alias.. ..table..}
        :fields {..field.. [..table-alias.. ..field..]}}

    (->  (table {..table.. ..table-alias..})
         (project {..field.. ..field-alias..}))
    => {:tables {..table-alias.. ..table..}
        :fields {..field-alias.. [..table-alias.. ..field..]}})


  (fact "projecting onto multiple fields from one table"
    (-> (table {..table.. ..table-alias..})
        (project [..field.. ..field2..]))
    => {:tables {..table-alias.. ..table..}
        :fields {..field.. [..table-alias.. ..field..]
                 ..field2.. [..table-alias.. ..field2..]}}

    (-> (table {..table.. ..table-alias..})
        (project {..field.. ..field-alias.., ..field2.. ..field2-alias..}))
    => {:tables {..table-alias.. ..table..}
        :fields {..field-alias.. [..table-alias.. ..field..]
                 ..field2-alias.. [..table-alias.. ..field2..]}})

  (fact "projecting one a field from multiple tables"
    (prerequisites ..tables.. =contains=> {:tables {..table.. ..table.., ..table2.. ..table2..}})
    
    (project ..tables.. [..field..])
    => (throws clojure.lang.ExceptionInfo)

    (project ..tables.. {..field.. ..field-alias..})
    => (throws clojure.lang.ExceptionInfo))

  (fact "projecting a subset of the current projection from one table"
    ;; Note that these two facts are retaining the ..table.. in the
    ;;   fields rather than using the ..table-alias.. they would have
    ;;   used otherwise. This shows they are filtering the existing
    ;;   fields rather than removing and re-adding the fields.
    (project {:tables {..table-alias.. ..table..}
              :fields {..field.. [..table.. ..field..]
                       ..field2.. [..table.. ..field2..]}}
             [..field..])
    => {:tables {..table-alias.. ..table..}
        :fields {..field.. [..table.. ..field..]}}

    (project {:tables {..table-alias.. ..table..}
              :fields {..field.. [..table.. ..field..]
                       ..field2.. [..table.. ..field2..]}}
             {..field.. ..field-alias..})
    => {:tables {..table-alias.. ..table..}
        :fields {..field-alias.. [..table.. ..field..]}})

  (fact "projecting a disjoint set from the current projection from one table"
    (project {:tables {..table-alias.. ..table..}
              :fields {[..table.. ..field..] ..field..}}
             [..field2..])
    => {:tables {..table-alias.. ..table..}
        :fields {..field2.. [..table-alias.. ..field2..]}})

  (fact "projecting a superset from the current projection from one table"
    (project {:tables {..table.. ..table..}
              :fields {..field.. [..table.. ..field..]}}
             [..field.. ..field2..])
    => {:tables {..table.. ..table..}
        :fields {..field.. [..table.. ..field..]
                 ..field2.. [..table.. ..field2..]}}

    ;; once again - note the table aliases
    (project {:tables {..table-alias.. ..table..}
              :fields {..field.. [..table.. ..field..]}}
             [..field.. ..field2..])
    => {:tables {..table-alias.. ..table..}
        :fields {..field.. [..table.. ..field..]
                 ..field2.. [..table-alias.. ..field2..]}})



  (fact "projecting a subset of the current projection from two table"
    (prerequisites ..tables.. =contains=> {:tables {..table.. ..table.., ..table2.. ..table2..}})

    (project {:tables ..tables..
              :fields {..field.. [..table.. ..field..]
                       ..field2.. [..table.. ..field2..]}}
             [..field..])
    => {:tables ..tables..
        :fields {..field.. [..table.. ..field..]}}

    (project {:tables ..tables..
              :fields {..field.. [..table.. ..field..]
                       ..field2.. [..table.. ..field2..]}}
             {..field.. ..field-alias..})
    => {:tables ..tables..
        :fields {..field-alias.. [..table.. ..field..]}})

  (fact "projecting a disjoint set from the current projection from two tables"
    (project {:tables {..table-alias.. ..table.., ..table2-alias.. ..table2..}
              :fields {[..table.. ..field..] ..field..}}
             [..field2..])
    => (throws clojure.lang.ExceptionInfo))

  (fact "projecting a superset from the current projection from two tables"
    (project {:tables {..table-alias.. ..table.., ..table2-alias.. ..table2..}
              :fields {[..table.. ..field..] ..field..}}
             [..field.. ..field2..])
    => (throws clojure.lang.ExceptionInfo)))



(fact "renaming fields does what you'd expect (renames them, removes the old alias)"
  (prerequisites (keyword? ..table..) => true
                 (keyword? ..field..) => true
                 (keyword? ..field2..) => true
                 (keyword? ..field-alias..) => true)

  (-> (table ..table..)
      (project [..field..])
      (rename {..field.. ..field-alias..}))
  => {:tables {..table.. ..table..}
      :fields {..field-alias.. [..table.. ..field..]}}

  (-> (table ..table..)
      (project [..field.. ..field2..])
      (rename {..field.. ..field-alias..}))
  => {:tables {..table.. ..table..}
      :fields {..field-alias.. [..table.. ..field..]
               ..field2.. [..table.. ..field2..]}}

  (-> {:tables {..table.. ..table..,
                ..table2.. ..table2..}
       :fields {..field.. [..table.. ..field..]
                ..field2.. [..table.. ..field2..]}}
      (rename {..field.. ..field-alias..}))
  => {:tables {..table.. ..table.., ..table2.. ..table2..}
      :fields {..field-alias.. [..table.. ..field..]
               ..field2.. [..table.. ..field2..]}})


(fact "joining tables merges tables and fields"
  )