@startuml uc-08-run-adventure
autonumber
title UC-08 Run Adventure (design sequence)
actor Player
participant "AdventureBoundary\n«/api/characters/{id}/adventure»" as boundary <<boundary>>
participant "AdventureService\nsb-core::adventure::run_adventure" as control <<control>>
participant "ResourceRegenerator\napply_regen" as regen <<entity>>
participant "CombatEngine\nsb-core::combat" as combat <<entity>>
participant "Combatant\nCombatStats" as combatant <<entity>>
participant "SpellEffect / BardSong\nsb-core::{spells,songs}" as fx <<entity>>

== Validate ==
Player -> boundary : POST adventure (zone, default skara_brae_streets)
boundary -> control : run_adventure(rng, character, zone)
alt zone unknown
  control --> boundary : 404
else HP <= 0
  control --> boundary : 400
else nerve < zone cost
  control --> boundary : 422
else ok
end
control -> regen : apply_regen(character)
regen --> control : character (regenerated)
control -> control : nerve -= zone cost

== Encounter ==
control -> combatant : pick_enemy(rng, weighted table)
alt unknown enemy id (data error)
  control --> boundary : 500 DomainError::UnknownEncounterEnemy
end

== Combat (rounds) ==
loop until one side falls
  control -> combat : open_ended_roll(rng, attack)
  combat -> combat : OB vs DB, crit table\n(level-gap damage caps)
  combat -> fx : bard song effect, active spell dmg/heal
  combat --> control : round result
end

== Resolve ==
alt player victory
  control -> combatant : XP + gold per enemy def
  control -> combatant : HP = last defender HP
  control -> combatant : loot rolls (catalogue items only)
else defeat
  control -> combatant : HP = 0, no rewards
end
control -> fx : spell-point upkeep (win or lose)
control --> boundary : {zone, enemy, combat_log, loot}
boundary --> Player : {zone, enemy, combat_log, loot}
@enduml