#!/usr/bin/env bash
# Exercise 2: robust building blocks — retry, require_env, semver, safe cleanup (medium)
# Run with: bash linux_bash_scripting_exercise_2.sh
# Must work on bash 3.2 (macOS) — no associative arrays, no ${x^^}, no mapfile.
#
# STEP 1: retry ATTEMPTS CMD...  — run CMD until it succeeds, at most ATTEMPTS
#         times; return 0 on success, 1 if all attempts fail. Print
#         "attempt N failed" to STDERR after each failure. Sleep $RETRY_DELAY
#         seconds between attempts (default 1; the self-check sets 0).
# STEP 2: require_env NAME...    — return 0 if every named variable is set and
#         non-empty; otherwise print "missing: NAME" (one line per missing
#         variable) to stderr and return 1. Hint: indirect expansion ${!name:-}
# STEP 3: semver_gt A B          — return 0 if version A > B (MAJOR.MINOR.PATCH,
#         optional leading "v"), else 1. Compare numerically: 1.10.0 > 1.9.9.
# STEP 4: bump VERSION PART      — print the bumped version for PART major|minor|patch
#         (bump 1.4.2 minor → 1.5.0); return 2 and print nothing for an unknown PART
# STEP 5: with_tempdir CMD...    — create a temp dir, run CMD with the temp dir path
#         as its last argument, ALWAYS delete the temp dir afterwards (even if CMD
#         fails), and return CMD's exit status.

set -uo pipefail

retry() {
  # TODO
  :
}

require_env() {
  # TODO
  :
}

semver_gt() {
  # TODO
  :
}

bump() {
  # TODO
  :
}

with_tempdir() {
  # TODO
  :
}

# --- self-check: do not modify below this line ---
all_ok=true
check() {
  if [[ "$2" == "$3" ]]; then echo "ok   $1"; else echo "FAIL $1 (got '$2', expected '$3')"; all_ok=false; fi
}
export RETRY_DELAY=0
STATE="$(mktemp)"; trap 'rm -f "$STATE"' EXIT
flaky() { local n; n=$(($(cat "$STATE" 2>/dev/null || echo 0) + 1)); echo "$n" > "$STATE"; [[ $n -ge 3 ]]; }

echo 0 > "$STATE"; retry 5 flaky 2>/dev/null; check "retry succeeds on 3rd attempt" "$?" "0"
check "retry ran flaky 3 times" "$(cat "$STATE")" "3"
echo 0 > "$STATE"; retry 2 flaky 2>/dev/null; check "retry gives up after 2" "$?" "1"
check "retry stderr messages" "$(echo 0 > "$STATE"; retry 2 flaky 2>&1 >/dev/null)" "$(printf 'attempt 1 failed\nattempt 2 failed')"

unset NOPE1 NOPE2 || true; export HAVE1=x
require_env HAVE1 2>/dev/null; check "require_env ok" "$?" "0"
require_env HAVE1 NOPE1 NOPE2 2>/dev/null; check "require_env missing → 1" "$?" "1"
check "require_env messages" "$(require_env NOPE1 HAVE1 NOPE2 2>&1)" "$(printf 'missing: NOPE1\nmissing: NOPE2')"
export EMPTY=""; require_env EMPTY 2>/dev/null; check "require_env empty counts as missing" "$?" "1"

semver_gt 1.10.0 1.9.9; check "1.10.0 > 1.9.9" "$?" "0"
semver_gt v2.0.0 1.99.99; check "v2.0.0 > 1.99.99" "$?" "0"
semver_gt 1.4.2 1.4.2; check "1.4.2 !> 1.4.2" "$?" "1"
semver_gt 1.4.2 1.4.10; check "1.4.2 !> 1.4.10" "$?" "1"

check "bump minor" "$(bump 1.4.2 minor)" "1.5.0"
check "bump major" "$(bump 1.4.2 major)" "2.0.0"
check "bump patch" "$(bump 1.4.9 patch)" "1.4.10"
bump 1.4.2 huge >/dev/null; check "bump unknown → 2" "$?" "2"

LEFT=""
mkfile() { touch "$1/x"; LEFT="$1"; return 3; }
with_tempdir mkfile; rc=$?
check "with_tempdir returns CMD status" "$rc" "3"
check "with_tempdir passed a directory" "$([[ -n "$LEFT" ]] && echo yes || echo no)" "yes"
check "with_tempdir cleaned up" "$([[ -n "$LEFT" && ! -e "$LEFT" ]] && echo yes || echo no)" "yes"

if $all_ok; then echo "PASS"; else echo "FAIL"; fi