#!/bin/bash
# Materia Supervisor - Continuous pipeline orchestration
# Inspired by TigerBeetle's CFO supervisor pattern
# https://github.com/tigerbeetle/tigerbeetle/blob/main/src/scripts/cfo_supervisor.sh
#
# Git-based deployment: pulls latest code from master and runs pipelines via uv

set -euo pipefail

# Configuration
readonly CHECK_INTERVAL=900  # 15 minutes
readonly MATERIA_REPO="/opt/materia/repo"
readonly STATE_DIR="/var/lib/materia"

# Schedules (cron-style times in UTC)
readonly EXTRACT_SCHEDULE_HOUR=2  # 02:00 UTC
readonly TRANSFORM_SCHEDULE_HOUR=3  # 03:00 UTC

# Ensure state directory exists
mkdir -p "$STATE_DIR"

log() {
    echo "[$(date '+%Y-%m-%d %H:%M:%S')] $*"
}

log_error() {
    echo "[$(date '+%Y-%m-%d %H:%M:%S')] ERROR: $*" >&2
}

# Update code from git
update_code() {
    log "Checking for code updates..."
    cd "$MATERIA_REPO"

    # Fetch latest from master
    if ! git fetch origin master 2>&1 | grep -v "^From"; then
        log_error "Failed to fetch from git"
        return 1
    fi

    # Check if update available
    LOCAL=$(git rev-parse HEAD)
    REMOTE=$(git rev-parse origin/master)

    if [ "$LOCAL" != "$REMOTE" ]; then
        log "New version detected: $LOCAL -> $REMOTE"

        # Pull latest code
        if git pull origin master; then
            log "Code updated successfully"

            # Update dependencies
            log "Updating dependencies with uv sync..."
            if uv sync; then
                log "Dependencies updated"
                return 0
            else
                log_error "Failed to update dependencies"
                return 1
            fi
        else
            log_error "Failed to pull code"
            return 1
        fi
    fi

    log "Already up to date at $(git rev-parse --short HEAD)"
    return 1  # Return 1 to indicate no update (not an error)
}

# Run pipeline using materia CLI via uv
run_pipeline() {
    local pipeline=$1
    local date=$(date -u +%Y-%m-%d)
    local state_file="$STATE_DIR/${pipeline}_last_run"

    log "Running $pipeline pipeline..."

    cd "$MATERIA_REPO"
    if uv run materia pipeline run "$pipeline"; then
        log "$pipeline completed successfully"
        echo "$date" > "$state_file"
        return 0
    else
        log_error "$pipeline failed"
        return 1
    fi
}

# Check if pipeline should run today
should_run_pipeline() {
    local pipeline=$1
    local schedule_hour=$2
    local current_hour=$(date -u +%H)
    local current_date=$(date -u +%Y-%m-%d)
    local state_file="$STATE_DIR/${pipeline}_last_run"

    # Only run at the scheduled hour
    if [ "$current_hour" -ne "$schedule_hour" ]; then
        return 1
    fi

    # Check if already ran today
    if [ -f "$state_file" ]; then
        local last_run=$(cat "$state_file")
        if [ "$last_run" = "$current_date" ]; then
            return 1  # Already ran today
        fi
    fi

    return 0  # Should run
}

# Main supervisor loop
main() {
    log "Materia supervisor starting..."
    log "Repository: $MATERIA_REPO"
    log "Extract schedule: daily at ${EXTRACT_SCHEDULE_HOUR}:00 UTC"
    log "Transform schedule: daily at ${TRANSFORM_SCHEDULE_HOUR}:00 UTC"
    log "Check interval: ${CHECK_INTERVAL}s"

    # Ensure repo exists
    if [ ! -d "$MATERIA_REPO/.git" ]; then
        log_error "Repository not found at $MATERIA_REPO"
        log_error "Run bootstrap script first!"
        exit 1
    fi

    # Show initial version
    cd "$MATERIA_REPO"
    log "Starting at commit: $(git rev-parse --short HEAD)"

    while true; do
        # Check for code updates every loop
        update_code || true

        # Check extract schedule
        if should_run_pipeline "extract" "$EXTRACT_SCHEDULE_HOUR"; then
            run_pipeline extract || true
        fi

        # Check transform schedule
        if should_run_pipeline "transform" "$TRANSFORM_SCHEDULE_HOUR"; then
            run_pipeline transform || true
        fi

        sleep "$CHECK_INTERVAL"
    done
}

# Run main loop
main