#!/bin/sh
# Pi adapter: implements the Mosaic adapter contract for the pinned
# @earendil-works/pi-coding-agent CLI.
#
# Contract: see /opt/mosaic/adapters/README.md.
# Headless (default): stdout = response only; stderr = diagnostics; exit 0.
# Interactive (MOSAIC_INTERACTIVE=1): full pi TUI on the attached terminal.
set -eu

[ -n "${MOSAIC_SYSTEM_PROMPT_FILE:-}" ] || { echo "pi adapter: MOSAIC_SYSTEM_PROMPT_FILE is required" >&2; exit 2; }
[ -r "$MOSAIC_SYSTEM_PROMPT_FILE" ] || { echo "pi adapter: system prompt not readable: $MOSAIC_SYSTEM_PROMPT_FILE" >&2; exit 2; }
# MOSAIC_AGENT_NAME is optional in headless mode (identity section is then
# omitted); interactive launches always set it via scripts/agent.sh.

: "${PI_PROVIDER:?pi adapter: PI_PROVIDER is required}"
: "${PI_MODEL:?pi adapter: PI_MODEL is required}"

INTERACTIVE="${MOSAIC_INTERACTIVE:-}"
if [ "$INTERACTIVE" != "1" ]; then
    [ -n "${MOSAIC_REQUEST:-}" ] || { echo "pi adapter: MOSAIC_REQUEST is required" >&2; exit 2; }
fi

# Workspace (M5): run inside the provided workspace when present.
if [ -n "${MOSAIC_WORKSPACE:-}" ]; then
    mkdir -p "$MOSAIC_WORKSPACE"
    cd "$MOSAIC_WORKSPACE"
fi

# Session (M6/M11): default ephemeral (--no-session). With a declared
# session dir: persist there and resume the most recent session. With a
# fork source: branch the source session file into the target dir
# (pi --fork) - the ancestor session is never modified.
SESSION_FLAGS="--no-session"
if [ -n "${MOSAIC_SESSION_FORK:-}" ]; then
    [ -n "${MOSAIC_SESSION_DIR:-}" ] || { echo "pi adapter: session fork requires MOSAIC_SESSION_DIR" >&2; exit 2; }
    mkdir -p "$MOSAIC_SESSION_DIR"
    SESSION_FLAGS="--fork $MOSAIC_SESSION_FORK --session-dir $MOSAIC_SESSION_DIR"
elif [ -n "${MOSAIC_SESSION_DIR:-}" ]; then
    mkdir -p "$MOSAIC_SESSION_DIR"
    SESSION_FLAGS="--session-dir $MOSAIC_SESSION_DIR"
    if [ -n "$(ls -A "$MOSAIC_SESSION_DIR" 2>/dev/null)" ]; then
        SESSION_FLAGS="$SESSION_FLAGS -c"
    fi
fi

# Capabilities (M5): explicit allowlist or no tools.
TOOLS_FLAG="--no-tools"
[ -n "${MOSAIC_TOOLS:-}" ] && TOOLS_FLAG="--tools $MOSAIC_TOOLS"

# Mode (M13): interactive TUI or one-shot print.
PRINT_MODE="-p"
REQUEST_ARG=""
if [ "$INTERACTIVE" = "1" ]; then
    PRINT_MODE=""
else
    REQUEST_ARG="$MOSAIC_REQUEST"
fi

# All flags documented in the pi package README (CLI Reference):
#   -p/--print     one-shot mode: print the response and exit (omitted in
#                  interactive TUI mode)
#   --system-prompt  replace the default prompt with the generated one
#   --no-*         no ambient context/skills/extensions/templates/themes
#   SESSION_FLAGS  ephemeral | persistent | forked (per env)
#   TOOLS_FLAG     per capabilities
#   --offline      no startup network operations (update checks/telemetry)
PROMPT_CONTENT="$(cat "$MOSAIC_SYSTEM_PROMPT_FILE")"
set -- \
    --offline \
    --no-extensions \
    --no-skills \
    --no-prompt-templates \
    --no-themes \
    --no-context-files \
    $TOOLS_FLAG \
    $SESSION_FLAGS \
    --provider "$PI_PROVIDER" \
    --model "$PI_MODEL" \
    --system-prompt "$PROMPT_CONTENT"
# One-shot mode appends -p and the request (both safely quoted);
# interactive mode appends nothing - clean TUI.
[ "$INTERACTIVE" = "1" ] || set -- "$@" -p "$MOSAIC_REQUEST"
exec pi "$@"