// Copyright (C) 2025 Emilis Bliūdžius
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as
// published by the Free Software Foundation, either version 3 of the
// License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

use core::num::NonZeroU8;

use crate::{
    character::CharacterId,
    diedto::DiedTo,
    error::GameError,
    game::night::{CurrentResult, Night, NightState, changes::NightChange},
    message::night::{ActionPrompt, ActionResult},
    role::RoleBlock,
};

use super::Result;
impl Night {
    #[allow(clippy::should_implement_trait)]
    pub fn next(&mut self) -> Result<()> {
        self.retroactive_role_blocks()?;
        self.next_state_process_maple_starving()?;

        match &self.night_state {
            NightState::Active {
                current_prompt,
                current_result: CurrentResult::Result(ActionResult::Continue),
                current_changes,
                ..
            } => {
                self.used_actions.push((
                    current_prompt.clone(),
                    ActionResult::Continue,
                    current_changes.clone(),
                ));
            }
            NightState::Active {
                current_prompt,
                current_result: CurrentResult::Result(ActionResult::GoBackToSleep),
                current_changes,
                ..
            } => {
                self.used_actions.push((
                    current_prompt.clone(),
                    ActionResult::GoBackToSleep,
                    current_changes.clone(),
                ));
            }
            NightState::Active {
                current_result: CurrentResult::Result(_),
                ..
            } => {
                // needs Continue, not Next
                return Err(GameError::AwaitingResponse);
            }
            NightState::Active {
                current_prompt,
                current_result: CurrentResult::GoBackToSleepAfterShown { result_with_data },
                current_changes,
                ..
            } => {
                self.used_actions.push((
                    current_prompt.clone(),
                    result_with_data.clone(),
                    current_changes.clone(),
                ));
            }
            NightState::Active {
                current_prompt: _,
                current_result: CurrentResult::None,
                ..
            } => return Err(GameError::AwaitingResponse),
            NightState::Complete => return Err(GameError::NightOver),
        }
        if let Some(prompt) = self.action_queue.pop_front() {
            if let ActionPrompt::Insomniac { character_id } = &prompt
                && self.get_visits_for(character_id.character_id).is_empty()
            {
                // skip!
                self.used_actions.pop(); // it will be re-added
                return self.next();
            }
            self.night_state = NightState::Active {
                current_prompt: prompt,
                current_result: CurrentResult::None,
                current_changes: Vec::new(),
                current_page: 0,
            };
        } else {
            self.night_state = NightState::Complete;
        }

        Ok(())
    }

    fn next_state_process_maple_starving(&mut self) -> Result<()> {
        let (maple_id, target) = match self.current_prompt() {
            Some((
                ActionPrompt::MapleWolf {
                    character_id,
                    kill_or_die,
                    marked,
                    ..
                },
                _,
            )) => {
                if *kill_or_die {
                    (character_id.character_id, *marked)
                } else {
                    return Ok(());
                }
            }
            Some(_) | None => return Ok(()),
        };

        let starve_change = if let Some(night) = NonZeroU8::new(self.night) {
            NightChange::Kill {
                target: maple_id,
                died_to: DiedTo::MapleWolfStarved { night },
            }
        } else {
            return Ok(());
        };

        let Some(target) = target else {
            return self.append_change(starve_change);
        };
        match self.died_to_tonight(target)? {
            Some(DiedTo::MapleWolf { source, .. }) => {
                if source != maple_id {
                    self.append_change(starve_change)?;
                }
            }
            Some(_) | None => {
                self.append_change(starve_change)?;
            }
        }

        Ok(())
    }

    fn retroactive_role_blocks(&mut self) -> Result<()> {
        let blocks = match &self.night_state {
            NightState::Active {
                current_changes, ..
            } => current_changes
                .iter()
                .filter_map(|c| match c {
                    NightChange::RoleBlock {
                        target, block_type, ..
                    } => Some((*target, *block_type)),
                    _ => None,
                })
                .collect::<Box<[_]>>(),
            NightState::Complete => return Err(GameError::NightOver),
        };
        for (target, block_type) in blocks {
            match block_type {
                RoleBlock::Direwolf => self.apply_direwolf_block_retroactively(target),
            }
        }

        Ok(())
    }

    fn apply_direwolf_block_retroactively(&mut self, target: CharacterId) {
        self.used_actions
            .iter_mut()
            .filter_map(|(prompt, res, changes)| match prompt.marked() {
                Some((marked, None)) => (marked == target).then_some((res, changes)),
                Some((marked1, Some(marked2))) => {
                    (marked1 == target || marked2 == target).then_some((res, changes))
                }
                None => None,
            })
            .for_each(|(result, changes)| {
                changes.clear();
                *result = ActionResult::RoleBlocked;
            });
    }
}