"""Run Leiden community detection (modularity or CPM)."""

import argparse
import sys
import os
sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))

import igraph as ig
import leidenalg

from config import NETWORKS, RESULTS_DIR, SEED
from load_data import load_edge_list, build_igraph, save_communities


def run_leiden(network_name, method_name, quality, resolution=None):
    net = NETWORKS[network_name]
    edge_df = load_edge_list(net["edge_tsv"])
    g, name_to_idx, idx_to_name = build_igraph(edge_df)

    print(f"  Graph: {g.vcount()} nodes, {g.ecount()} edges")

    if quality == "modularity":
        partition = leidenalg.find_partition(
            g, leidenalg.ModularityVertexPartition, seed=SEED
        )
    elif quality == "cpm":
        partition = leidenalg.find_partition(
            g, leidenalg.CPMVertexPartition,
            resolution_parameter=resolution, seed=SEED
        )
    else:
        raise ValueError(f"Unknown quality function: {quality}")

    print(f"  Found {len(partition)} communities, modularity={partition.modularity:.4f}")

    # Convert partition to node2com dict
    node2com = {}
    for comm_id, members in enumerate(partition):
        for idx in members:
            node2com[idx_to_name[idx]] = str(comm_id)

    out_path = os.path.join(RESULTS_DIR, network_name, method_name, "com.tsv")
    save_communities(node2com, out_path)
    print(f"  Saved to {out_path}")
    return node2com


if __name__ == "__main__":
    parser = argparse.ArgumentParser()
    parser.add_argument("--network", required=True)
    parser.add_argument("--method", required=True,
                        choices=["leiden_mod", "leiden_cpm_01", "leiden_cpm_001"])
    args = parser.parse_args()

    method_configs = {
        "leiden_mod": {"quality": "modularity"},
        "leiden_cpm_01": {"quality": "cpm", "resolution": 0.1},
        "leiden_cpm_001": {"quality": "cpm", "resolution": 0.01},
    }
    cfg = method_configs[args.method]
    print(f"Running {args.method} on {args.network}...")
    run_leiden(args.network, args.method, **cfg)