#!/usr/bin/env bash
# Complete current TODO and optionally start the next one
# Usage: jj-todo-done [NEXT_REV]
#
# If NEXT_REV is provided, starts working on that revision.
# If not provided, lists possible next TODOs (children of current) and exits.
#
# Example:
#   jj-todo-done           # Complete current, show next options
#   jj-todo-done abc123    # Complete current, start working on abc123

set -euo pipefail

SCRIPTS_DIR="$(dirname "$0")"

# Mark current as done (auto-detects current flag)
"$SCRIPTS_DIR/jj-flag-update" @ done

current=$(jj log -r @ --no-graph -T 'change_id.shortest(8)')

# Find children that are TODOs (have any flag)
children=$(jj log -r "children(@) & description(substring:\"[todo]\")" --no-graph -T 'change_id.shortest(8) ++ "\n"' 2>/dev/null || true)

if [[ -n "${1:-}" ]]; then
    # User specified next revision
    next="$1"
    jj edit "$next"
    "$SCRIPTS_DIR/jj-flag-update" @ wip
    echo ""
    echo "📋 Starting TODO:"
    echo "─────────────────"
    "$SCRIPTS_DIR/jj-show-desc" @
elif [[ -z "$children" ]]; then
    echo "✅ Completed: $current"
    echo ""
    echo "No pending TODO children found. You may be done with this chain!"
    echo ""
    echo "Check remaining TODOs with:"
    echo "  jj-find-flagged todo"
elif [[ $(echo "$children" | wc -l) -eq 1 ]]; then
    # Single child - start it automatically
    next=$(echo "$children" | tr -d '[:space:]')
    echo "✅ Completed: $current"
    echo ""
    jj edit "$next"
    "$SCRIPTS_DIR/jj-flag-update" @ wip
    echo ""
    echo "📋 Starting TODO:"
    echo "─────────────────"
    "$SCRIPTS_DIR/jj-show-desc" @
else
    # Multiple children - list them for user to choose
    echo "✅ Completed: $current"
    echo ""
    echo "Multiple next TODOs available. Choose one:"
    echo ""
    while IFS= read -r child; do
        [[ -z "$child" ]] && continue
        title=$(jj log -r "$child" --no-graph -T 'description.first_line()' 2>/dev/null || echo "(no description)")
        echo "  $child  $title"
    done <<< "$children"
    echo ""
    echo "Run: jj-todo-done <change-id>"
fi