#!/bin/bash
#
# signature_test.sh — one klammer, one interface (engine suite, tst/).
#
# A klammer may be defined separately for each target.  When it is, every
# target's definition carries its own parameter list, and those lists must
# agree: a klammer's interface is a property of the KLAMMER, not of the
# target it is being rendered to.  If they disagree, the same document would
# bind arguments differently — or fail — depending only on the target, which
# is exactly the thing an author must be able to rely on not happening.
#
# The engine enforces this rather than warning about it, and the remedy it
# names is the .k declaration: declare the parameters once, and give each
# target a "::" instance with no parameter list of its own.  That is the
# migration from repeating an argument list per target to declaring it once.
#
# These are engine tests, so they use -k none and define their own targets
# inline: a target is a Machine construct (@@@target), not owned by any
# klammer set.
#
# Usage: ./signature_test.sh   (needs KLAMMERTEXT_HOME set; ktext on PATH)
# Exit code: 0 if all tests pass, 1 otherwise.

PASS=0
FAIL=0
KTEXT=ktext
K=${KLAMMERTEXT_HOME:?KLAMMERTEXT_HOME must be set}

red=$'\033[31m'
green=$'\033[32m'
bold=$'\033[1m'
reset=$'\033[0m'

pass() { echo "${green}PASS${reset} $1"; PASS=$((PASS+1)); }
fail() {
    echo "${red}FAIL${reset} $1"
    echo "       expected: $2"
    echo "       got:      $3"
    FAIL=$((FAIL+1))
}

TARGETS='@@@target ta | Target A @@@
@@@target tb | Target B @@@
'

# accepted NAME SRC — the definitions are consistent and the klammer applies.
accepted() {
    local name="$1" src="$2" out
    out=$("$KTEXT" -k none -s "$TARGETS$src" -t ta -d 2>&1)
    if echo "$out" | grep -qi "error"; then
        fail "$name" "no error" "$(echo "$out" | grep -i -A1 error | tail -1)"
    else
        pass "$name"
    fi
}

# rejected NAME SRC PATTERN — the drift is caught, and the message says how.
rejected() {
    local name="$1" src="$2" want="$3" out
    out=$("$KTEXT" -k none -s "$TARGETS$src" -t ta -d 2>&1)
    if ! echo "$out" | grep -qi "error"; then
        fail "$name" "a definition error" "accepted"
    elif ! echo "$out" | grep -qF "$want"; then
        fail "$name" "message containing: $want" "$(echo "$out" | head -6 | tail -3)"
    else
        pass "$name"
    fi
}

echo "${bold}Klammer signature consistency${reset}"
echo "============================="
echo

accepted " 1. identical parameter lists" \
'@@k1.ta s :n : [*s*] @@
@@k1.tb s :n : [*s*] @@
@k1 x @'

rejected " 2. positional names differ" \
'@@k2.ta s : [*s*] @@
@@k2.tb t : [*t*] @@
@k2 x @' 'are not the same for every target'

rejected " 3. option names differ" \
'@@k3.ta s :one : [*s*] @@
@@k3.tb s :two : [*s*] @@
@k3 x @' 'are not the same for every target'

rejected " 4. defaults differ" \
'@@k4.ta s :n abc : [*s*] @@
@@k4.tb s :n xyz : [*s*] @@
@k4 x @' 'are not the same for every target'

rejected " 5. argument types differ" \
'@@k5.ta s :n.int : [*s*] @@
@@k5.tb s :n.word : [*s*] @@
@k5 x @' 'are not the same for every target'

echo
echo "-- the message must show HOW they differ, not just where"

# With more than two targets the designer would otherwise have to diff the
# definitions by hand; each target's own signature is listed beside its name.
name=" 6. each target's signature is shown"
out=$("$KTEXT" -k none -s "$TARGETS"'@@k6.ta s :one : [*s*] @@
@@k6.tb s :two : [*s*] @@
@k6 x @' -t ta -d 2>&1)
if echo "$out" | grep -q "ta .*s :one" && echo "$out" | grep -q "tb .*s :two"; then
    pass "$name"
else
    fail "$name" "both signatures listed by target" "$(echo "$out" | head -8 | tail -4)"
fi

# The error path once printed internal katom detail through msg(), which is
# debugging scaffolding and must never reach a user-facing message.
name=" 7. no internal debug output on the error path"
out=$("$KTEXT" -k none -s "$TARGETS"'@@k7.k s : a declaration @@
@@k7.ta s2 :other : [*s2*] @@
@k7 x @' -t ta -d 2>&1)
if echo "$out" | grep -q "klammer-definition"; then
    fail "$name" "no internal dump" "$(echo "$out" | head -2)"
else
    pass "$name"
fi

echo
echo "-- the remedy the message names"

accepted " 8. a .k declaration with :: instances" \
'@@k8.k s :n : a declaration @@
@@k8.ta :: [*s*] @@
@@k8.tb :: [*s*] @@
@k8 x @'

rejected " 9. a .k declaration plus a parameterized definition" \
'@@k9.k s : a declaration @@
@@k9.ta s2 :other : [*s2*] @@
@k9 x @' 'both a declaration'

echo
echo "============================="
echo "Results: ${green}$PASS passed${reset}, ${red}$FAIL failed${reset}"
[ $FAIL -eq 0 ]