use anyhow::Result;
use crossterm::event::Event;
use gnostr_asyncgit::{
    sync::{
        self,
        cred::{
            extract_username_password_for_fetch, need_username_password_for_fetch,
            BasicAuthCredential,
        },
        remotes::get_default_remote_for_fetch,
        RepoPathRef,
    },
    AsyncGitNotification, AsyncPull, FetchRequest, RemoteProgress,
};
use ratatui::{
    layout::Rect,
    text::Span,
    widgets::{Block, BorderType, Borders, Clear, Gauge},
    Frame,
};

use crate::{
    app::Environment,
    components::{
        visibility_blocking, CommandBlocking, CommandInfo, Component, CredComponent,
        DrawableComponent, EventState,
    },
    keys::SharedKeyConfig,
    popups::PushPopup,
    queue::{Action, InternalEvent, Queue},
    strings, try_or_popup,
    ui::{self, style::SharedTheme},
};

pub struct PullPopup {
    repo: RepoPathRef,
    visible: bool,
    git_fetch: AsyncPull,
    progress: Option<RemoteProgress>,
    pending: bool,
    branch: String,
    queue: Queue,
    theme: SharedTheme,
    key_config: SharedKeyConfig,
    input_cred: CredComponent,
}

impl PullPopup {
        pub fn new(env: &Environment) -> Self {
        Self {
            repo: env.repo.clone(),
            queue: env.queue.clone(),
            pending: false,
            visible: false,
            branch: String::new(),
            git_fetch: AsyncPull::new(env.repo.borrow().clone(), &env.sender_git),
            progress: None,
            input_cred: CredComponent::new(env),
            theme: env.theme.clone(),
            key_config: env.key_config.clone(),
        }
    }

        pub fn fetch(&mut self, branch: String) -> Result<()> {
        self.branch = branch;
        self.show()?;
        if need_username_password_for_fetch(&self.repo.borrow())? {
            let cred = extract_username_password_for_fetch(&self.repo.borrow())
                .unwrap_or_else(|_| BasicAuthCredential::new(None, None));
            if cred.is_complete() {
                self.fetch_from_remote(Some(cred))
            } else {
                self.input_cred.set_cred(cred);
                self.input_cred.show()
            }
        } else {
            self.fetch_from_remote(None)
        }
    }

    fn fetch_from_remote(&mut self, cred: Option<BasicAuthCredential>) -> Result<()> {
        self.pending = true;
        self.progress = None;
        self.git_fetch.request(FetchRequest {
            remote: get_default_remote_for_fetch(&self.repo.borrow())?,
            branch: self.branch.clone(),
            basic_credential: cred,
        })?;

        Ok(())
    }

        pub const fn any_work_pending(&self) -> bool {
        self.pending
    }

        pub fn update_git(&mut self, ev: AsyncGitNotification) {
        if self.is_visible() && ev == AsyncGitNotification::Pull {
            if let Err(error) = self.update() {
                self.pending = false;
                self.hide();
                self.queue.push(InternalEvent::ShowErrorMsg(format!(
                    "fetch failed:\n{error}"
                )));
            }
        }
    }

        fn update(&mut self) -> Result<()> {
        self.pending = self.git_fetch.is_pending()?;
        self.progress = self.git_fetch.progress()?;

        if !self.pending {
            if let Some((_bytes, err)) = self.git_fetch.last_result()? {
                if err.is_empty() {
                    self.try_ff_merge()?;
                } else {
                    anyhow::bail!(err);
                }
            }
        }

        Ok(())
    }

    // check if something is incoming and try a ff merge then
    fn try_ff_merge(&mut self) -> Result<()> {
        let branch_compare = sync::branch_compare_upstream(&self.repo.borrow(), &self.branch)?;
        if branch_compare.behind > 0 {
            let ff_res = sync::branch_merge_upstream_fastforward(&self.repo.borrow(), &self.branch);
            if let Err(err) = ff_res {
                log::trace!("ff failed: {}", err);
                self.confirm_merge(branch_compare.behind);
            }
        }

        self.hide();

        Ok(())
    }

    pub fn try_conflict_free_merge(&self, rebase: bool) {
        if rebase {
            try_or_popup!(
                self,
                "rebase failed:",
                sync::merge_upstream_rebase(&self.repo.borrow(), &self.branch)
            );
        } else {
            try_or_popup!(
                self,
                "merge failed:",
                sync::merge_upstream_commit(&self.repo.borrow(), &self.branch)
            );
        }
    }

    fn confirm_merge(&mut self, incoming: usize) {
        self.queue
            .push(InternalEvent::ConfirmAction(Action::PullMerge {
                incoming,
                rebase: sync::config_is_pull_rebase(&self.repo.borrow()).unwrap_or_default(),
            }));
        self.hide();
    }
}

impl DrawableComponent for PullPopup {
    fn draw(&self, f: &mut Frame, rect: Rect) -> Result<()> {
        if self.visible {
            let (state, progress) = PushPopup::get_progress(&self.progress);

            let area = ui::centered_rect_absolute(30, 3, f.area());

            f.render_widget(Clear, area);
            f.render_widget(
                Gauge::default()
                    .label(state.as_str())
                    .block(
                        Block::default()
                            .title(Span::styled(
                                strings::PULL_POPUP_MSG,
                                self.theme.title(true),
                            ))
                            .borders(Borders::ALL)
                            .border_type(BorderType::Thick)
                            .border_style(self.theme.block(true)),
                    )
                    .gauge_style(self.theme.push_gauge())
                    .percent(u16::from(progress)),
                area,
            );
            self.input_cred.draw(f, rect)?;
        }

        Ok(())
    }
}

impl Component for PullPopup {
    fn commands(&self, out: &mut Vec<CommandInfo>, force_all: bool) -> CommandBlocking {
        if self.is_visible() || force_all {
            if !force_all {
                out.clear();
            }

            if self.input_cred.is_visible() {
                return self.input_cred.commands(out, force_all);
            }
            out.push(CommandInfo::new(
                strings::commands::close_msg(&self.key_config),
                !self.pending,
                self.visible,
            ));
        }

        visibility_blocking(self)
    }

    fn event(&mut self, ev: &Event) -> Result<EventState> {
        if self.visible {
            if let Event::Key(_) = ev {
                if self.input_cred.is_visible() {
                    self.input_cred.event(ev)?;

                    if self.input_cred.get_cred().is_complete() || !self.input_cred.is_visible() {
                        self.fetch_from_remote(Some(self.input_cred.get_cred().clone()))?;
                        self.input_cred.hide();
                    }
                }
            }
            return Ok(EventState::Consumed);
        }
        Ok(EventState::NotConsumed)
    }

    fn is_visible(&self) -> bool {
        self.visible
    }

    fn hide(&mut self) {
        self.visible = false;
    }

    fn show(&mut self) -> Result<()> {
        self.visible = true;

        Ok(())
    }
}
