telltale-runtime 17.0.0

// Topology DSL Grammar

WHITESPACE = _{ " " | "\t" | "\r" | "\n" | COMMENT }
COMMENT = _{ "//" ~ (!"\n" ~ ANY)* ~ ("\n" | EOI) | "/*" ~ (!"*/" ~ ANY)* ~ "*/" }

// Top-level topology definition
topology = {
    SOI ~ "topology" ~ ident ~ "for" ~ ident ~ "{" ~ topology_body ~ "}" ~ EOI
}

topology_body = {
    topology_mode? ~ topology_mappings ~ role_constraints_block? ~ channel_capacities_block? ~ topology_constraints?
}

// Topology mode declaration
topology_mode = { "mode" ~ ":" ~ topology_mode_value ~ ";"? }
topology_mode_value = { ident ~ ("(" ~ ident ~ ")")? }

// Role to location mappings
topology_mappings = { topology_mapping* }
topology_mapping = { ident ~ ":" ~ location ~ ";"? }

// Location specification
// IMPORTANT: Order matters - endpoint must come before local_location
// to prevent "localhost" from matching "local"
location = {
    colocated_location
    | endpoint
    | local_location
}

// "local" keyword - only matches when NOT followed by alphanumeric
local_location = @{ "local" ~ !ASCII_ALPHANUMERIC }

colocated_location = { "colocated" ~ "(" ~ ident ~ ")" }

// Endpoint: host:port format
// Examples: localhost:8080, 192.168.1.1:9000, host.domain.com:443
endpoint = @{
    (ASCII_ALPHANUMERIC | "_" | "-" | ".")+ ~ ":" ~ (ASCII_ALPHANUMERIC | "_" | "-" | "." | ":")+
}

// Role family constraints block
role_constraints_block = { "role_constraints" ~ "{" ~ role_constraint_decl* ~ "}" }

role_constraint_decl = { ident ~ ":" ~ role_constraint_spec ~ ";"? }

role_constraint_spec = {
    min_constraint ~ ("," ~ max_constraint)?
    | max_constraint ~ ("," ~ min_constraint)?
}

min_constraint = { "min" ~ "=" ~ integer }
max_constraint = { "max" ~ "=" ~ integer }

// Topology constraints block
topology_constraints = { "constraints" ~ "{" ~ constraint_decl* ~ "}" }

constraint_decl = {
    colocated_constraint
    | separated_constraint
    | pinned_constraint
    | region_constraint
}

colocated_constraint = { "colocated" ~ ":" ~ ident ~ "," ~ ident ~ ";"? }
separated_constraint = { "separated" ~ ":" ~ role_list_inline ~ ";"? }
pinned_constraint = { "pinned" ~ ":" ~ ident ~ "->" ~ location ~ ";"? }
region_constraint = { "region" ~ ":" ~ ident ~ "->" ~ ident ~ ";"? }

role_list_inline = { ident ~ ("," ~ ident)+ }

// Channel capacity block (bits)
channel_capacities_block = { "channel_capacities" ~ "{" ~ channel_capacity_decl* ~ "}" }

channel_capacity_decl = { ident ~ "->" ~ ident ~ ":" ~ integer ~ ";"? }

// Basic tokens
ident = @{ ASCII_ALPHA ~ (ASCII_ALPHANUMERIC | "_")* }
integer = @{ ASCII_DIGIT+ }
string = @{ "\"" ~ (!"\"" ~ ANY)* ~ "\"" }