import {GameState, getCharacterById} from "./GameState";
import {CharacterId} from "./Character";

export interface BaseDoable {
    readonly type: string
}

export type LogEntry = {
    readonly markdown: string
    readonly children: readonly LogEntry[]
}

export interface DoableResults {
    readonly resultState: GameState
    readonly logEntry: LogEntry|null
}

export interface DoablesResults {
    readonly resultState: GameState
    readonly logEntries: readonly LogEntry[]
}

export interface DoableEvaluator<DataType extends BaseDoable> {
    readonly type: DataType["type"]
    evaluate(data: DataType, state: GameState, direction: DoableDirection): DoableResults
}

export interface GenericAction extends BaseDoable {
    readonly type: "generic",
    readonly text: string
    readonly user: CharacterId|null
    readonly target: CharacterId|null
    readonly effects: readonly Doable[]
}

export const GenericActionEvaluator = {
    type: "generic",
    evaluate(data: GenericAction, state: GameState, direction: DoableDirection): DoableResults {
        function runEffects(currentState: GameState): DoablesResults {
            return evaluateDoables(data.effects, state, direction)
        }
        function logSelf(currentState: GameState): string {
            return data.text.replaceAll(/@[TU]/g, (substring: string): string => {
                switch (substring) {
                    case "@T":
                        // TODO: make "character links" a function, likely with identifier characters
                        return data.target !== null ? `[${getCharacterById(currentState, data.target)?.name ?? "???"}](#character/${data.target})` : "@T"
                    case "@U":
                        return data.user !== null ? `[${getCharacterById(currentState, data.user)?.name ?? "???"}](#character/${data.user})` : "@U"
                    default:
                        return substring
                }
            })
        }
        switch (direction) {
            case DoableDirection.Do: {
                const markdown = logSelf(state)
                const {resultState, logEntries} = runEffects(state)
                return {
                    resultState,
                    logEntry: {
                        markdown,
                        children: logEntries
                    }
                }
            }
            case DoableDirection.Undo: {
                const {resultState, logEntries} = runEffects(state)
                const markdown = logSelf(resultState)
                return {
                    resultState,
                    logEntry: {
                        markdown,
                        children: logEntries
                    }
                }
            }
        }
    },
} as const satisfies DoableEvaluator<GenericAction>
/**
 * @dataclass(**JsonableDataclassArgs)
 * class AbilityAction(Doable):
 *     name: str
 *     user: Target | None
 *     costs: tuple[DamageEffect, ...]
 *     effects: tuple[Effect, ...]
 *
 *
 * @dataclass(**JsonableDataclassArgs)
 * class ModifyCharacterEffect(Doable):
 *     index: int
 *     old_character_data: Character | None
 *     new_character_data: Character | None
 *
 *     def __post_init__(self):
 *         if self.old_character_data is None and self.new_character_data is None:
 *             raise ValueError("At least one of old_character_data or new_character_data must be non-None")
 *
 * @dataclass(**JsonableDataclassArgs)
 * class ModifyClockEffect(Doable):
 *     index: int
 *     old_clock_data: Clock | None
 *     new_clock_data: Clock | None
 *
 *     def __post_init__(self):
 *         if self.old_clock_data is None and self.new_clock_data is None:
 *             raise ValueError("At least one of old_clock_data or new_clock_data must be non-None")
 *
 *
 * @dataclass(**JsonableDataclassArgs)
 * class EndTurnAction(Doable):
 *     turn_ending_index: int
 *     activating_side: CombatSide
 *
 *
 * @dataclass(**JsonableDataclassArgs)
 * class StartTurnAction(Doable):
 *     turn_starting_index: int
 *     old_active_side: CombatSide
 *
 *
 * @dataclass(**JsonableDataclassArgs)
 * class StartRoundAction(Doable):
 *     last_round: int
 *     old_active_side: CombatSide
 *     old_turns_remaining: tuple[int, ...]
 *     next_round: int
 *     activating_side: CombatSide
 *
 *
 * @dataclass(**JsonableDataclassArgs)
 * class StartBattleAction(Doable):
 *     starting_side: CombatSide
 *     starting_round: int
 *
 *
 * @dataclass(**JsonableDataclassArgs)
 * class EndBattleAction(Doable):
 *     old_round_number: int
 *     old_active_side: CombatSide
 *     old_starting_side: CombatSide
 *     old_turns_remaining: tuple[int, ...]
 *
 * @dataclass(**JsonableDataclassArgs)
 * class OpportunityEffect(LogOnly, Effect):
 *     target: Target | None
 *     opportunity_text: str
 *
 *     def log_message(self, user: Target | None = None) -> str:
 *         return f'**Opportunity!!** {log_substitute(self.opportunity_text, user=user, target=self.target)}'
 *
 * @dataclass(**JsonableDataclassArgs)
 * class DamageEffect(Effect):
 *     target: Target
 *     target_type: CharacterType
 *     attribute: Counter
 *     damage: int
 *     old_value: int
 *     new_value: int
 *     max_value: int | None
 *     element: Element
 *     affinity: Affinity
 *     piercing: bool
 *
 *     def do(self, combat: "CombatStatus", source: Union[Action, "Effect", None] = None) -> "CombatStatus":
 *         return combat.alter_character(self.target, lambda c: c.set_counter_current(self.attribute, self.new_value))
 *
 *     def undo(self, combat: "CombatStatus", source: Union[Action, "Effect", None] = None) -> "CombatStatus":
 *         return combat.alter_character(self.target, lambda c: c.set_counter_current(self.attribute, self.old_value))
 *
 *     def log_message(self, user: Target | None = None) -> str:
 *         state_change = None
 *         if self.attribute == Counter.HP:
 *             if self.old_value > self.new_value == 0:
 *                 state_change = ['+ **KO**']
 *             elif self.new_value > self.old_value == 0:
 *                 if self.new_value * 2 > self.max_value:
 *                     state_change = ['- **KO**']
 *                 else:
 *                     state_change = ['- **KO**', '+ **Crisis**']
 *             elif self.old_value * 2 > self.max_value >= self.new_value * 2:
 *                 state_change = '+ **Crisis**'
 *             elif self.new_value * 2 > self.max_value >= self.old_value * 2:
 *                 state_change = '- **Crisis**'
 *         affinity = ''
 *         if self.affinity == Affinity.Absorb:
 *             affinity = "?"
 *         elif self.affinity == Affinity.Immune:
 *             affinity = " ✖"
 *         elif self.affinity == Affinity.Resistant:
 *             affinity = "…"
 *         elif self.affinity == Affinity.Vulnerable:
 *             affinity = "‼"
 *         attribute = (f'{self.element.value}{"!" if self.piercing else ""}'
 *                      if self.attribute == Counter.HP
 *                      else f'{self.attribute.ctr_name_abbr(self.target_type)}')
 *         sign = '-' if self.damage >= 0 else '+'
 *         return '\n'.join(
 *             [log_substitute(
 *                 f'@T: [{sign}{abs(self.damage)}{affinity}] {attribute}',
 *                 user=user, target=self.target)] +
 *             [log_substitute(f'@T: [{s}]') for s in state_change])
 *
 *
 * @dataclass(**JsonableDataclassArgs)
 * class StatusEffect(Effect):
 *     target: Target
 *     old_status: str | None
 *     new_status: str | None
 *
 *     @staticmethod
 *     def alter_status(c: Character, old_status: str | None, new_status: str | None) -> Character:
 *         if old_status is None and new_status is not None:
 *             return c.add_status(new_status)
 *         elif new_status is None and old_status is not None:
 *             return c.remove_status(old_status)
 *         elif new_status is not None and old_status is not None:
 *             return c.replace_status(old_status, new_status)
 *         else:
 *             return c
 *
 *     def __post_init__(self):
 *         if self.old_status is None and self.new_status is None:
 *             raise ValueError("At least one of old_status or new_status must be non-None")
 *
 *     def do(self, combat: CombatStatus, source: Union[Action, Effect, None] = None) -> CombatStatus:
 *         return combat.alter_character(
 *             self.target, lambda c: StatusEffect.alter_status(c, self.old_status, self.new_status))
 *
 *     def undo(self, combat: CombatStatus, source: Union[Action, Effect, None] = None) -> CombatStatus:
 *         return combat.alter_character(
 *             self.target, lambda c: StatusEffect.alter_status(c, self.new_status, self.old_status))
 *
 *     def log_message(self, user: Target | None = None) -> str | None:
 *         if self.old_status is not None and self.new_status is None:
 *             return log_substitute(v=f'@T: [- {self.old_status}]', user=user, target=self.target)
 *         if self.new_status is not None and self.old_status is None:
 *             return log_substitute(v=f'@T: [+ {self.old_status}]', user=user, target=self.target)
 *         if self.old_status is not None and self.new_status is not None:
 *             return log_substitute(v=f'@T: [{self.old_status} -> {self.new_status}]', user=user, target=self.target)
 *         pass
 *
 *
 * @dataclass(**JsonableDataclassArgs)
 * class FPBonusEffect(Effect):
 *     user: Target
 *     rerolls: int
 *     modifier: int
 *     fp_spent: int
 *     old_fp: int
 *     new_fp: int
 *
 *     def do(self, combat: CombatStatus, source: Union[Action, Effect, None] = None) -> CombatStatus:
 *         return combat.alter_character(
 *             self.user,
 *             lambda c: c.set_counter_current(Counter.SP, self.new_fp)
 *         ).add_fp_spent(self.fp_spent)
 *
 *     def undo(self, combat: CombatStatus, source: Union[Action, Effect, None] = None) -> CombatStatus:
 *         return combat.alter_character(
 *             self.user,
 *             lambda c: c.set_counter_current(Counter.SP, self.old_fp)
 *         ).add_fp_spent(-self.fp_spent)
 *
 *     def log_message(self, user: Target | None = None) -> str | None:
 *         bonuses = []
 *         if self.rerolls > 0:
 *             if self.rerolls > 1:
 *                 bonuses.append(f"{self.rerolls} rerolls")
 *             else:
 *                 bonuses.append("a reroll")
 *         if self.modifier != 0:
 *             bonuses.append(f"a {self.modifier:+} {'bonus' if self.modifier > 0 else 'penalty'}")
 *         if len(bonuses) == 0:
 *             return None
 *         affected = ''
 *         if self.user != user:
 *             affected = log_substitute(" on @U's roll", user=user, target=self.user)
 *         return f"{log_substitute('@T', user=user, target=self.user)} " \
 *                f"spent **{self.fp_spent} FP** for {' and '.join(bonuses)}{affected}!"
 *
 * TODO: add an FP gain effect for villains (affects all party members) and fumbles and trait failures
 *
 * @dataclass(**JsonableDataclassArgs)
 * class MissEffect(LogOnly, Effect):
 *     miss_type: MissType
 *     target: Target
 *
 *     def log_message(self, user: Target | None = None) -> str | None:
 *         if self.miss_type == MissType.Missed:
 *             return log_substitute(f"It missed @T!", user=user, target=self.target)
 *         elif self.miss_type == MissType.Dodged:
 *             return log_substitute(f"@T dodged it!", user=user, target=self.target)
 *         elif self.miss_type == MissType.Avoided:
 *             return log_substitute(f"@T avoided it!", user=user, target=self.target)
 *         elif self.miss_type == MissType.Blocked:
 *             return log_substitute("@T blocked it!", user=user, target=self.target)
 *         elif self.miss_type == MissType.Immunity:
 *             return log_substitute("@T is immune!", user=user, target=self.target)
 *         elif self.miss_type == MissType.Repelled:
 *             return log_substitute("@T repelled it!", user=user, target=self.target)
 *         elif self.miss_type == MissType.Countered:
 *             return log_substitute("@T countered it!", user=user, target=self.target)
 *         elif self.miss_type == MissType.Parried:
 *             return log_substitute("@T parried it!", user=user, target=self.target)
 *         elif self.miss_type == MissType.Protected:
 *             return log_substitute("@T was protected from it!", user=user, target=self.target)
 *         elif self.miss_type == MissType.Resisted:
 *             return log_substitute("@T resisted it!", user=user, target=self.target)
 *         elif self.miss_type == MissType.Shielded:
 *             return log_substitute("@T shielded against it!", user=user, target=self.target)
 *         else:
 *             return log_substitute(f"@T: {self.miss_type.value}", user=user, target=self.target)
 *
 *
 * @dataclass(**JsonableDataclassArgs)
 * class ClockTickEffect(Effect):
 *     clock_index: int
 *     old_definition: Clock
 *     new_value: int
 *     delta: int
 *
 *     def do(self, combat: "CombatStatus", source: Union[Action, "Effect", None] = None) -> "CombatStatus":
 *         return combat.alter_clock(self.clock_index, lambda c: c.set_value(self.new_value))
 *
 *     def undo(self, combat: "CombatStatus", source: Union[Action, "Effect", None] = None) -> "CombatStatus":
 *         return combat.alter_clock(self.clock_index, lambda c: c.set_value(self.old_definition.current))
 *
 *     def log_message(self, user: Target | None = None) -> str | None:
 *         return (f'The clock **{self.old_definition.name}** ticked {"up" if self.delta > 0 else "down"} {self.delta} '
 *                 f'tick{"" if abs(self.delta) == 1 else "s"}.')
 */

const DoableEvaluators = [
    GenericActionEvaluator,
] as const satisfies readonly DoableEvaluator<unknown & BaseDoable>[]

export type Doable = typeof DoableEvaluators[number] extends DoableEvaluator<infer ActionType> ? ActionType : never

export enum DoableDirection {
    Do = "do",
    Undo = "undo",
}

export function evaluateDoable<T extends Doable>(doable: T, gameState: GameState, direction: DoableDirection): DoableResults {
    const evaluator: DoableEvaluator<T>|undefined = DoableEvaluators.find((evaluator) => evaluator.type === doable.type)
    if (!evaluator) {
        return {
            resultState: gameState,
            logEntry: null
        }
    }
    return evaluator.evaluate(doable, gameState, direction)
}

export function evaluateDoables(doables: readonly Doable[], gameState: GameState, direction: DoableDirection): DoablesResults {
    let currentState = gameState
    const sortedDoables = direction === DoableDirection.Undo ? doables.slice().reverse() : doables
    const logEntries: LogEntry[] = []
    for (const doable of sortedDoables) {
        const {resultState, logEntry} = evaluateDoable(doable, gameState, direction)
        currentState = resultState
        if (logEntry) {
            logEntries.push(logEntry)
        }
    }
    return {
        resultState: currentState,
        logEntries: direction === DoableDirection.Undo ? logEntries.reverse() : logEntries,
    }
}