Function build_and_validate_commodity_graphs_for_model

pub fn build_and_validate_commodity_graphs_for_model(
    processes: &ProcessMap,
    commodities: &CommodityMap,
    region_ids: &IndexSet<RegionID>,
    years: &[u32],
    time_slice_info: &TimeSliceInfo,
) -> Result<HashMap<(RegionID, u32), Vec<CommodityID>>>

Builds and validates commodity graphs for the entire model.

This function creates commodity flow graphs for each region/year combination in the model, validates the graph structure against commodity type rules, and determines the optimal investment order for commodities.

The validation process checks three time slice levels:

• Annual: Validates annual-level commodities and processes
• Seasonal: Validates seasonal-level commodities and processes for each season
• Day/Night: Validates day/night-level commodities and processes for each time slice

Arguments

• processes - All processes in the model with their flows and activity limits
• commodities - All commodities with their types and demand specifications
• region_ids - Collection of regions to model
• years - Years to analyse
• time_slice_info - Time slice configuration (seasons, day/night periods)

Returns

A map from (region, year) to the ordered list of commodities for investment decisions. The ordering ensures that leaf-node commodities (those with no outgoing edges) are solved first.

Errors

Returns an error if:

• Any commodity graph contains cycles
• Commodity type rules are violated (e.g., SVD commodities being consumed)
• Demand cannot be satisfied