#!/bin/bash
# o — unified CLI for the ollie 9P namespace.
#
# Subcommands:
#   read   <file>         Read a file from the active session/agent
#   ls     [path]         List namespace entries
#   ctl    <command>      Send a control command (stop, compact, kill, ...)
#   prompt                Interactive REPL for submitting prompts
#   tail                  Tail chat output from the active agent
#   env                   Print resolved session/agent environment
#
# Environment:
#   session               Session name (set via 'eval $(o env)')
#   agent                 Agent name
#
# If session/agent are not set and there is exactly one session, it is
# selected automatically. If multiple exist, lists them and exits.

set -euo pipefail

# ── Resolve session and agent ────────────────────────────────────

resolve_session() {
    local s="${session:-}"
    if [[ -n "$s" ]]; then
        echo "$s"
        return
    fi
    # Count sessions from idx
    local idx
    idx=$(ollie-9p read session/idx 2>/dev/null || true)
    if [[ -z "$idx" ]]; then
        return
    fi
    local names
    names=$(echo "$idx" | cut -f1 | sort -u)
    local count
    count=$(echo "$names" | wc -l)
    if [[ $count -eq 1 ]]; then
        echo "$names"
    else
        echo "error: multiple sessions active, set one:" >&2
        echo "$names" | sed 's/^/  /' >&2
        echo "" >&2
        echo "  export session=<name>  OR  eval \$(o env <name>)" >&2
        exit 1
    fi
}

resolve_agent() {
    local s="$1"
    local a="${agent:-}"
    if [[ -n "$a" ]]; then
        echo "$a"
        return
    fi
    if [[ -z "$s" ]]; then
        return
    fi
    # List agents in session
    local agents
    agents=$(ollie-9p ls "session/$s/agent" 2>/dev/null | grep -v '^new$' || true)
    if [[ -z "$agents" ]]; then
        return
    fi
    local count
    count=$(echo "$agents" | wc -l)
    if [[ $count -eq 1 ]]; then
        echo "$agents"
    else
        echo "error: multiple agents in session '$s', set one:" >&2
        echo "$agents" | sed 's/^/  /' >&2
        echo "" >&2
        echo "  export agent=<name>  OR  eval \$(o env $s <agent>)" >&2
        exit 1
    fi
}

require_session() {
    local s
    s=$(resolve_session)
    if [[ -z "$s" ]]; then
        echo "error: no session active (start one, or export session=<name>)" >&2
        exit 1
    fi
    echo "$s"
}

require_agent() {
    local s="$1"
    local a
    a=$(resolve_agent "$s")
    if [[ -z "$a" ]]; then
        echo "error: no agent set (export agent=<name>)" >&2
        exit 1
    fi
    echo "$a"
}

agent_path() {
    local s a
    s=$(require_session)
    a=$(require_agent "$s")
    echo "session/$s/agent/$a"
}

# ── Subcommands ──────────────────────────────────────────────────

cmd_read() {
    if [[ $# -lt 1 ]]; then
        echo "usage: o read <file> [session [agent]]" >&2
        exit 1
    fi
    local file="$1"; shift
    [[ $# -ge 1 ]] && export session="${1}" && shift
    [[ $# -ge 1 ]] && export agent="${1}" && shift
    local path
    path=$(agent_path)
    ollie-9p read "$path/$file"
}

cmd_ls() {
    local s
    s=$(resolve_session) || true
    if [[ $# -ge 1 ]]; then
        local target="$1"; shift
        if [[ "$target" == session/* || "$target" == elevate/* ]]; then
            ollie-9p ls "$target"
        elif [[ -n "$s" ]]; then
            local a
            a=$(resolve_agent "$s") || true
            if [[ -n "$a" ]]; then
                ollie-9p ls "session/$s/agent/$a/$target"
            else
                ollie-9p ls "session/$s/$target"
            fi
        else
            ollie-9p ls "$target"
        fi
    elif [[ -n "$s" ]]; then
        local a
        a=$(resolve_agent "$s") || true
        if [[ -n "$a" ]]; then
            ollie-9p ls "session/$s/agent/$a"
        else
            ollie-9p ls "session/$s"
        fi
    else
        ollie-9p ls session
    fi
}

cmd_ctl() {
    if [[ $# -lt 1 ]]; then
        echo "usage: o ctl <command> [args...]" >&2
        echo "  commands: stop, compact, kill, clear, model <m>, backend <b>, cwd <d>" >&2
        exit 1
    fi
    local path
    path=$(agent_path)
    echo "$*" | ollie-9p write "$path/ctl"
}

cmd_prompt() {
    local path s a
    path=$(agent_path)
    s=$(require_session)
    a=$(require_agent "$s")
    echo "[$s/$a]"
    echo "Enter prompts (blank line sends, Ctrl+D exits)."
    echo "Slash commands: /stop /compact /kill /clear /model /backend /cwd /help"
    echo ""

    local buf="" line
    while true; do
        local prompt_str
        if [[ -z "$buf" ]]; then
            prompt_str=$'\033[1m>\033[0m '
        else
            prompt_str="  "
        fi
        if ! IFS= read -e -r -p "$prompt_str" line; then
            # EOF — send remaining buffer if any
            if [[ -n "$buf" ]]; then
                history -s "$buf"
                printf '%s\n' "$buf" | ollie-9p write "$path/prompt"
            fi
            printf "\n"
            break
        fi
        # Slash commands (only when buffer is empty — first line)
        if [[ -z "$buf" && "$line" == /* ]]; then
            history -s "$line"
            local cmd="${line#/}"
            case "$cmd" in
                stop)    echo "stop" | ollie-9p write "$path/ctl"; echo "[stopped]" ;;
                compact) echo "compact" | ollie-9p write "$path/ctl"; echo "[compacted]" ;;
                kill)    echo "kill" | ollie-9p write "session/$s/ctl"; echo "[session killed]"; break ;;
                clear)   echo "clear" | ollie-9p write "$path/ctl"; echo "[cleared]" ;;
                model*)  echo "$cmd" | ollie-9p write "$path/ctl"; echo "[${cmd}]" ;;
                backend*) echo "$cmd" | ollie-9p write "$path/ctl"; echo "[${cmd}]" ;;
                cwd*)    echo "$cmd" | ollie-9p write "$path/ctl"; echo "[${cmd}]" ;;
                help)
                    echo "  /stop      — interrupt running agent"
                    echo "  /compact   — compact context"
                    echo "  /kill      — kill the session"
                    echo "  /clear     — clear history"
                    echo "  /model X   — switch model"
                    echo "  /backend X — switch backend"
                    echo "  /cwd X     — change working directory"
                    ;;
                *)  echo "unknown command: /$cmd (try /help)" ;;
            esac
            continue
        fi
        if [[ -z "$line" && -n "$buf" ]]; then
            # Blank line sends accumulated buffer
            history -s "$buf"
            printf '%s\n' "$buf" | ollie-9p write "$path/prompt"
            buf=""
        elif [[ -z "$line" ]]; then
            continue
        else
            if [[ -n "$buf" ]]; then
                buf="$buf"$'\n'"$line"
            else
                buf="$line"
            fi
        fi
    done
}

cmd_tail() {
    local path
    path=$(agent_path)
    exec ollie-9p read "$path/chat"
}

cmd_readloop() {
    if [[ $# -lt 1 ]]; then
        echo "usage: o readloop <file>" >&2
        echo "  read in a loop — re-reads after each return" >&2
        exit 1
    fi
    local file="$1"; shift
    local path
    path=$(agent_path)
    while true; do
        ollie-9p read "$path/$file" || break
    done
}

cmd_env() {
    # Accept optional positional args to override
    [[ $# -ge 1 ]] && export session="${1}" && shift
    [[ $# -ge 1 ]] && export agent="${1}" && shift

    local s a
    s=$(require_session)
    a=$(require_agent "$s")
    echo "export session=$s"
    echo "export agent=$a"
}

cmd_stop() {
    local path
    path=$(agent_path)
    echo "stop" | ollie-9p write "$path/ctl"
}

cmd_kill() {
    local s
    s=$(require_session)
    echo "kill" | ollie-9p write "session/$s/ctl"
}

cmd_tui() {
    local s a
    s=$(require_session)
    a=$(require_agent "$s")

    local tmux_session="o-${s}"

    # Subcommand: o tui exit
    if [[ "${1:-}" == "exit" ]]; then
        tmux kill-session -t "$tmux_session" 2>/dev/null && echo "[killed $tmux_session]" || echo "no tui session: $tmux_session"
        return
    fi

    # Kill existing tmux session if present
    tmux kill-session -t "$tmux_session" 2>/dev/null || true

    # Create new detached tmux session
    # Pane 0: chat tail (left, large)
    tmux new-session -d -s "$tmux_session" -c "$HOME" -x 200 -y 50 \
        -e "session=$s" -e "agent=$a"
    tmux send-keys -t "$tmux_session" "o tail" Enter

    # Pane 1: state monitor (top-right)
    tmux split-window -t "$tmux_session" -h -l 40 \
        -e "session=$s" -e "agent=$a"
    tmux send-keys -t "$tmux_session" "o readloop statewait" Enter

    # Pane 2: spare shell (bottom-right, below state)
    tmux split-window -t "$tmux_session" -v \
        -e "session=$s" -e "agent=$a"

    # Pane 3: prompt REPL (bottom, full width)
    tmux split-window -t "$tmux_session:0.0" -v -l 8 \
        -e "session=$s" -e "agent=$a"
    tmux send-keys -t "$tmux_session" "o prompt" Enter

    # Focus the prompt pane
    tmux select-pane -t "$tmux_session:0.3"

    # Attach
    exec tmux attach -t "$tmux_session"
}

cmd_help() {
    cat <<'EOF'
usage: o <command> [args...]

commands:
  read <file>       Read a file from the active agent's namespace
  readloop <file>   Read in a loop (re-reads after each return)
  ls [path]         List namespace entries (defaults to agent dir)
  ctl <cmd>         Send control command (stop, compact, kill, ...)
  stop              Interrupt the running agent
  kill              Kill the active session
  prompt            Interactive multi-line prompt REPL
  tail              Stream chat output
  tui               Launch tmux layout (chat + prompt + state + shell)
  tui exit          Kill the tmux TUI session
  env [session] [agent]  Print session/agent env vars (eval-able)
  help              Show this help

environment:
  session           Active session name
  agent             Active agent name

If only one session/agent exists, it is auto-selected.
If multiple exist, you must choose: eval $(o env <session> [agent])
EOF
}

# ── Dispatch ─────────────────────────────────────────────────────

if [[ $# -lt 1 ]]; then
    cmd_help
    exit 0
fi

subcmd="$1"; shift
case "$subcmd" in
    read)   cmd_read "$@" ;;
    readloop) cmd_readloop "$@" ;;
    ls)     cmd_ls "$@" ;;
    ctl)    cmd_ctl "$@" ;;
    stop)   cmd_stop "$@" ;;
    kill)   cmd_kill "$@" ;;
    prompt) cmd_prompt "$@" ;;
    tail)   cmd_tail "$@" ;;
    tui)    cmd_tui "$@" ;;
    env)    cmd_env "$@" ;;
    help|-h|--help) cmd_help ;;
    *)
        echo "unknown command: $subcmd" >&2
        echo "run 'o help' for usage" >&2
        exit 1
        ;;
esac