#!/bin/sh
# Runs the tasks of a plan one after another, each in its own fresh OpenCode session, and stops
# at the first task that does not end cleanly. This is the owner's tool; the implementing model
# never runs it.
#
# Usage:   tools/run-plan.sh docs/plans/M2a [FIRST]      FIRST is a task number such as 04
# Options (environment):
#   OPENCODE_MODEL     model to use (default straylight/laguna-s-2.1; OpenCode's own default differs).
#                      The part after the provider (`ornith-1.5-35b-a3b`) names the model in each
#                      commit's `Co-Authored-By: <model> <agent@wntrmute.dev>` trailer and in the log.
#   OPENCODE_FLAGS     extra flags for `opencode run`
#   PLUGINS=1          load OpenCode's external plugins and let it read ~/.claude/CLAUDE.md. By
#                      default each session runs with `--pure` and OPENCODE_DISABLE_CLAUDE_CODE=1:
#                      a global plugin that rewrites the prompt forces a full re-read on a model
#                      that cannot rewind its cache (implementer lessons, T48).
#   SESSION_LIMIT_MIN  minutes a session may run before it is stopped (default 90)
#   SLOTS_URL          llama-server's slots URL, for example
#                      http://127.0.0.1:8081/slots?model=ornith-1.5-35b-a3b. When set, a session is
#                      stopped once no slot has been busy for IDLE_LIMIT_MIN minutes (default 10).
#                      Trial: not yet used on a run.
#   RESUME=1           when a session ends, or is stopped at SESSION_LIMIT_MIN, with work left
#                      uncommitted, resume it once, in a new session with the same limit.
#   DRY_RUN=1          print what would be run and stop
# Each session runs as the `implement` agent of ./opencode.json: its permissions deny edits to the
# plans and design documents, reads outside the repository, subagents and pushes.
set -eu

plan="${1:?usage: tools/run-plan.sh docs/plans/<milestone> [FIRST]}"
first="${2:-00}"
model="${OPENCODE_MODEL:-straylight/laguna-s-2.1}"
agent="${model##*/}"
trailer="Co-Authored-By: $agent <agent@wntrmute.dev>"
limit="${SESSION_LIMIT_MIN:-90}"
idle="${IDLE_LIMIT_MIN:-10}"
log=docs/implementer-log.md
milestone=$(basename "$plan")
runs=".state/runs/$milestone"

[ -d "$plan" ] || { echo "run-plan: $plan is not a directory" >&2; exit 2; }
[ -f "$log" ] || { echo "run-plan: run this from the repository root" >&2; exit 2; }
mkdir -p "$runs"

# One OpenCode session with prompt $1, appended to the task's run log. Returns opencode's status,
# 124 when the session outlived $limit minutes, or 125 when SLOTS_URL showed no busy slot for $idle
# minutes. A stopped session is killed by process group (it may have started cargo), never with
# `pkill`, which would match this script too.
run_session() {
    set -m
    if [ "${PLUGINS:-0}" = 1 ]; then
        pure=""
    else
        pure="--pure"
        export OPENCODE_DISABLE_CLAUDE_CODE=1
    fi
    # shellcheck disable=SC2086
    opencode run $pure --agent implement -m "$model" ${OPENCODE_FLAGS:-} --title "$milestone/$name" \
        "$1" >> "$runs/$name.log" 2>&1 &
    pid=$!
    set +m
    started=$(date +%s)
    busy=$started
    why=0
    while kill -0 "$pid" 2> /dev/null; do
        sleep 10
        now=$(date +%s)
        if [ $((now - started)) -ge $((limit * 60)) ]; then
            why=124
            break
        fi
        if [ -n "${SLOTS_URL:-}" ]; then
            if curl -s -m 10 "$SLOTS_URL" | grep -Eq '"is_processing": *true'; then
                busy=$now
            fi
            if [ $((now - busy)) -ge $((idle * 60)) ]; then
                why=125
                break
            fi
        fi
    done
    if [ "$why" != 0 ]; then
        kill -TERM "-$pid" 2> /dev/null || kill -TERM "$pid" 2> /dev/null || true
        sleep 30
        kill -KILL "-$pid" 2> /dev/null || true
        wait "$pid" 2> /dev/null || true
        return "$why"
    fi
    status=0
    wait "$pid" || status=$?
    return "$status"
}

for task in "$plan"/[0-9][0-9]-*.md; do
    name=$(basename "$task" .md)
    number=$(echo "$name" | cut -c1-2)
    [ "$number" -ge "$first" ] || continue
    row="Your log row's Task cell is \`$milestone/$name\`, and you are $agent: write $agent in its Model column, and end the commit message with this line, exactly: $trailer"
    prompt="Read \`$task\` and do exactly that task. Do its steps in order. Run step 1 (usually a cp) before you Read any crate source, tests/support, or docs/implementer-log.md. $row"

    if [ "${DRY_RUN:-0}" = 1 ]; then
        echo "opencode run --agent implement -m $model ${OPENCODE_FLAGS:-} --title $milestone/$name \"$prompt\""
        continue
    fi
    if [ -n "$(git status --porcelain)" ]; then
        echo "run-plan: the working tree is not clean before $name; stopping" >&2
        exit 1
    fi

    before=$(git rev-parse HEAD)
    : > "$runs/$name.log"
    echo "=== $milestone/$name: started $(date '+%H:%M:%S')"
    # A new `opencode run` is a new session: nothing carries over from the task before.
    rc=0
    run_session "$prompt" || rc=$?
    # A session that ended, or ran out of time, part-way through a task is resumed once. One stopped
    # for idling (125) is not: the server, not the task, is the likely cause.
    if { [ "$rc" = 0 ] || [ "$rc" = 124 ]; } && [ "${RESUME:-0}" = 1 ] \
        && [ "$(git rev-parse HEAD)" = "$before" ] && [ -n "$(git status --porcelain)" ]; then
        if [ "$rc" = 124 ]; then
            echo "=== $milestone/$name: stopped at $limit minutes with work uncommitted"
        fi
        echo "=== $milestone/$name: work left uncommitted; resuming once $(date '+%H:%M:%S')"
        rc=0
        run_session "The previous session on \`$task\` left uncommitted work (see \`git diff\`). Do not start over. Finish the task, run the gate, commit, and write the log row. $row" || rc=$?
    fi
    case "$rc" in
        0) ;;
        124) echo "run-plan: $name ran past $limit minutes and was stopped; see $runs/$name.log" >&2; exit 1 ;;
        125) echo "run-plan: no llama slot was busy for $idle minutes in $name, so it was stopped; see $runs/$name.log" >&2; exit 1 ;;
        *) echo "run-plan: opencode exited with status $rc in $name; see $runs/$name.log" >&2; exit 1 ;;
    esac
    echo "=== $milestone/$name: session ended $(date '+%H:%M:%S')"

    # The task must have left exactly what AGENTS.md asks for: a commit carrying the trailer, a
    # clean tree, and a `done` row in the log. Anything else needs a person, so stop.
    if [ "$(git rev-parse HEAD)" = "$before" ]; then
        echo "run-plan: $name made no commit; stopping" >&2
        exit 1
    fi
    if [ -n "$(git status --porcelain)" ]; then
        echo "run-plan: $name left uncommitted changes; stopping" >&2
        exit 1
    fi
    if ! git log -1 --format=%B | grep -qxF "$trailer"; then
        echo "run-plan: $name's commit lacks the line '$trailer'; stopping" >&2
        exit 1
    fi
    if git show HEAD -- "$log" | grep -Eq "^\+\| *$milestone/$name *\|[^|]*\| *stopped *\|"; then
        echo "run-plan: $name stopped and said why in its log row; stopping" >&2
        git show HEAD -- "$log" | grep -E "^\+\| *$milestone/$name *\|" | cut -c2- >&2
        exit 1
    fi
    if ! grep -Eq "^\| *$milestone/$name *\|[^|]*\| *done *\|" "$log"; then
        echo "run-plan: no 'done' row for $milestone/$name in $log; stopping" >&2
        grep -E "^\| *$milestone/$name *\|" "$log" >&2 || true
        exit 1
    fi
    echo "=== $milestone/$name: done ($(git log -1 --format=%h))"
done
echo "run-plan: every task from $first on ended cleanly. Ready for review."