#!/usr/bin/env nextflow
nextflow.enable.dsl=2

// Define parameters — PVC mount paths for k8s execution
params.protein1_fasta = '/omic/eureka/bioemu/input/trp_cage.fasta'
params.protein2_fasta = '/omic/eureka/bioemu/input/villin_headpiece.fasta'
params.complex_name = "protein_complex"
params.exp_dG = -10.0  // kcal/mol (placeholder experimental value)
params.outdir = '/omic/eureka/bioemu/output'
params.cache_dir = '/tmp/bioemu_cache'

// Parameters for structure generation and analysis
params.num_samples = 10
params.batch_size = 5
params.temperature = 300
params.n_clusters = 5

process GENERATE_STRUCTURE {
    container 'harbor.cluster.omic.ai/omic/bioemu:latest'
    publishDir "${params.outdir}/${params.complex_name}/${protein_id}", mode: 'copy'

    input:
        tuple val(protein_id), path(fasta)

    output:
        tuple val(protein_id), path("${protein_id}_topology.pdb"), path("${protein_id}_samples.xtc")

    script:
    """
    # Extract sequence from FASTA
    SEQUENCE=\$(grep -v ">" ${fasta} | tr -d '\\n')

    # Create cache dir
    mkdir -p ${params.cache_dir}

    # Run BioEmu
    python3 -m bioemu.sample \\
        --sequence "\${SEQUENCE}" \\
        --num_samples ${params.num_samples} \\
        --batch_size_100 ${params.batch_size} \\
        --output_dir . \\
        --cache_embeds_dir ${params.cache_dir}

    # Rename output files
    mv topology.pdb ${protein_id}_topology.pdb
    mv samples.xtc ${protein_id}_samples.xtc
    """
}

process CALCULATE_BINDING {
    container 'harbor.cluster.omic.ai/omic/bioemu:latest'
    publishDir "${params.outdir}/${params.complex_name}/analysis", mode: 'copy'

    input:
        path protein1_topology
        path protein1_samples
        path protein2_topology
        path protein2_samples

    output:
        path "binding_energy.csv"
        path "binding_energy_report.txt"
        path "energy_comparison.png"

    script:
    """
    # Run binding energy calculation
    python3 /opt/bioemu/scripts/calculate_binding.py \\
        --protein1_topology ${protein1_topology} \\
        --protein1_samples ${protein1_samples} \\
        --protein2_topology ${protein2_topology} \\
        --protein2_samples ${protein2_samples} \\
        --temperature ${params.temperature} \\
        --n_clusters ${params.n_clusters} \\
        --output binding_energy.csv \\
        --plot energy_comparison.png

    # Generate report
    echo "# Binding Free Energy Analysis: ${params.complex_name}" > binding_energy_report.txt
    echo "======================================================" >> binding_energy_report.txt
    echo "## Experimental Value (Database)" >> binding_energy_report.txt
    echo "ΔG = ${params.exp_dG} kcal/mol" >> binding_energy_report.txt
    echo "" >> binding_energy_report.txt

    # Extract predicted value
    PREDICTED_DG=\$(grep -A1 "binding_free_energy" binding_energy.csv | tail -n1 | cut -d',' -f2)

    echo "## BioEmu Prediction" >> binding_energy_report.txt
    echo "ΔG = \${PREDICTED_DG} kcal/mol" >> binding_energy_report.txt
    echo "" >> binding_energy_report.txt

    # Calculate comparison metrics
    echo "## Comparison" >> binding_energy_report.txt
    ABS_DIFF=\$(python3 -c "print('%.2f' % abs(float('\${PREDICTED_DG}') - (${params.exp_dG})))")
    REL_ERROR=\$(python3 -c "print('%.2f' % (((float('\${PREDICTED_DG}') - (${params.exp_dG}))/(${params.exp_dG}))*100))")

    echo "Absolute Difference: \${ABS_DIFF} kcal/mol" >> binding_energy_report.txt
    echo "Relative Error: \${REL_ERROR}%" >> binding_energy_report.txt
    """
}

workflow {
    // Create channel for proteins
    protein_ch = Channel.fromList([
        tuple("protein1", file(params.protein1_fasta)),
        tuple("protein2", file(params.protein2_fasta))
    ])

    // Generate structures
    GENERATE_STRUCTURE(protein_ch)

    // Extract structure files for each protein
    protein1_files = GENERATE_STRUCTURE.out
                      .filter { it[0] == "protein1" }
                      .map { it -> tuple(it[1], it[2]) }
                      .first()

    protein2_files = GENERATE_STRUCTURE.out
                      .filter { it[0] == "protein2" }
                      .map { it -> tuple(it[1], it[2]) }
                      .first()

    // Calculate binding energy
    CALCULATE_BINDING(
        protein1_files[0],  // protein1_topology.pdb
        protein1_files[1],  // protein1_samples.xtc
        protein2_files[0],  // protein2_topology.pdb
        protein2_files[1]   // protein2_samples.xtc
    )
}