digraph job_flow {
    rankdir=TB
    node [shape=box, style=rounded, fontname="Helvetica"]
    edge [fontname="Helvetica", fontsize=10]

    labelloc="t"
    label="MPR - Job Flow"
    fontsize=16
    fontname="Helvetica-Bold"

    graph [splines=ortho, nodesep=0.6, ranksep=0.6]

    // API entry points
    subgraph cluster_api {
        label="API Entry Points"
        style=dashed
        color=gray

        rest_create [label="POST /api/jobs/", shape=ellipse]
        gql_create [label="mutation createJob", shape=ellipse]
        rest_cancel [label="POST /api/jobs/{id}/cancel", shape=ellipse]
        rest_callback [label="POST /api/jobs/{id}/callback", shape=ellipse]
    }

    // Job states
    subgraph cluster_states {
        label="Job States"
        style=filled
        fillcolor="#f8f8f8"

        pending [label="PENDING", fillcolor="#ffc107", style="filled,rounded"]
        processing [label="PROCESSING", fillcolor="#17a2b8", style="filled,rounded", fontcolor=white]
        completed [label="COMPLETED", fillcolor="#28a745", style="filled,rounded", fontcolor=white]
        failed [label="FAILED", fillcolor="#dc3545", style="filled,rounded", fontcolor=white]
        cancelled [label="CANCELLED", fillcolor="#6c757d", style="filled,rounded", fontcolor=white]
    }

    // State transitions
    pending -> processing [xlabel="worker picks up"]
    processing -> completed [xlabel="success"]
    processing -> failed [xlabel="error"]
    pending -> cancelled [xlabel="user cancels"]
    processing -> cancelled [xlabel="user cancels"]
    failed -> pending [xlabel="retry"]

    rest_create -> pending
    gql_create -> pending
    rest_cancel -> cancelled [style=dashed]

    // Executor dispatch
    subgraph cluster_dispatch {
        label="Executor Dispatch"
        style=filled
        fillcolor="#fff8e8"

        dispatch [label="MPR_EXECUTOR", shape=diamond]
    }

    pending -> dispatch

    // Local path
    subgraph cluster_local {
        label="Local Mode (Celery)"
        style=filled
        fillcolor="#e8f4e8"

        celery_task [label="Celery Task\n(transcode queue)"]
        s3_download [label="S3 Download\n(MinIO)"]
        ffmpeg_local [label="FFmpeg\ntranscode/trim"]
        s3_upload [label="S3 Upload\n(MinIO)"]
        db_update [label="DB Update\n(update_job_progress)"]
    }

    dispatch -> celery_task [xlabel="local"]
    celery_task -> s3_download
    s3_download -> ffmpeg_local
    ffmpeg_local -> s3_upload
    s3_upload -> db_update
    db_update -> completed [style=dotted]

    // Lambda path
    subgraph cluster_lambda {
        label="Lambda Mode (AWS)"
        style=filled
        fillcolor="#fde8d0"

        sfn_start [label="Step Functions\nstart_execution"]
        lambda_fn [label="Lambda\nFFmpeg container"]
        s3_dl_aws [label="S3 Download\n(AWS)"]
        ffmpeg_aws [label="FFmpeg\ntranscode/trim"]
        s3_ul_aws [label="S3 Upload\n(AWS)"]
        callback [label="HTTP Callback\nPOST /jobs/{id}/callback"]
    }

    dispatch -> sfn_start [xlabel="lambda"]
    sfn_start -> lambda_fn
    lambda_fn -> s3_dl_aws
    s3_dl_aws -> ffmpeg_aws
    ffmpeg_aws -> s3_ul_aws
    s3_ul_aws -> callback
    callback -> completed [style=dotted]

    rest_callback -> completed [style=dashed, xlabel="Lambda reports"]
}