//! Anonymous usage sharing (docs/privacy.md): the question the first run asks once, and Help ›
//! Settings, where it is changed. The choice is kept in the preferences ([`crate::files::Prefs`]);
//! the events are [`fieldcraft_engine::usage`]'s, and the host sends them.
//!
//! The window records only when the host says this run may ([`ModelApp::with_usage`]: the build
//! has an analytics key, and neither `FIELDCRAFT_TELEMETRY=0`, CI nor automation turned it off)
//! and the user said yes.

use egui::RichText;
use fieldcraft_engine::usage::{self, Event, Identity, Origin};

use crate::ModelApp;
use crate::files::Prompt;

/// What is sent, event by event.
pub const PRIVACY_URL: &str = "https://github.com/jyviko/fieldcraft/blob/main/docs/privacy.md";
/// The question, as the first run asks it.
pub const QUESTION: &str = "Help improve FieldCraft by sharing anonymous usage: which tools you use, nothing from your models.";
const DETAIL: &str = "Counted: the commands you run (their names, how long they took, whether they failed), the steps from a design to results, \
                      the samples you open, and the version, OS and a random id for this install. Never sent: file names or paths, geometry, model \
                      contents, parameter values or messages.";

/// What the host provides when this run may share usage.
pub struct UsageHost {
    /// `desktop` or `web`.
    pub platform: &'static str,
    pub os: &'static str,
    pub arch: &'static str,
    /// A new random install id; `None` when there is no randomness to make one.
    pub new_id: Box<dyn Fn() -> Option<String>>,
}

impl ModelApp {
    /// This run may share usage (the host checked the build's key and the environment): ask the
    /// user once, or record if they already agreed.
    pub fn with_usage(mut self, host: UsageHost) -> Self {
        self.usage = Some(host);
        self.apply_usage();
        self
    }

    /// The user's preferences as last saved.
    pub fn prefs(&self) -> &crate::files::Prefs {
        &self.prefs
    }

    /// Whether this run can share usage at all.
    pub fn usage_available(&self) -> bool {
        self.usage.is_some()
    }

    /// Start or stop recording as the preferences say.
    fn apply_usage(&mut self) {
        let Some(host) = &self.usage else { return };
        if self.prefs.usage_sharing != Some(true) {
            usage::disable();
            return;
        }
        if self.prefs.install_id.is_empty() {
            let Some(id) = (host.new_id)() else {
                log::warn!("usage sharing: no random install id could be made");
                return;
            };
            self.prefs.install_id = id;
        }
        let identity = Identity {
            install_id: self.prefs.install_id.clone(),
            platform: host.platform,
            os: host.os,
            arch: host.arch,
            app_version: crate::VERSION,
        };
        usage::enable(identity, self.prefs.usage_automation);
    }

    /// Change the choices (the consent question, Help › Settings, `ui.prompt`) and keep them.
    pub fn set_usage(&mut self, sharing: bool, automation: bool) {
        self.prefs.usage_sharing = Some(sharing);
        self.prefs.usage_automation = automation;
        // Agreeing makes the install id, which is kept with the choice.
        self.apply_usage();
        self.prefs.save(self.services.prefs.as_ref());
    }

    /// Answer the first run's question.
    pub fn answer_consent(&mut self, share: bool) {
        if self.prompt == Some(Prompt::Consent) {
            self.prompt = None;
        }
        self.set_usage(share, self.prefs.usage_automation);
    }

    /// Open Help › Settings.
    pub fn open_settings(&mut self) {
        self.prompt = Some(Prompt::Settings);
        self.ui.menu = None;
    }

    /// The window is closing: the session's length.
    pub fn usage_closing(&self) {
        if self.usage.is_some() {
            usage::closing();
        }
    }

    /// Ask the question once, when nothing else is being asked.
    pub(crate) fn ask_consent(&mut self) {
        if self.usage.is_some() && self.prefs.usage_sharing.is_none() && self.prompt.is_none() && !self.consent_asked {
            self.consent_asked = true;
            self.prompt = Some(Prompt::Consent);
        }
    }

    /// Record something the user did in the window (not a script or an agent driving it).
    pub(crate) fn record_ui(&self, event: Event) {
        if !self.session.origin.is_some_and(Origin::automated) {
            usage::record(event);
        }
    }

    /// Run `f` with the session's commands counted as coming from `origin`.
    pub fn with_origin<R>(&mut self, origin: Origin, f: impl FnOnce(&mut Self) -> R) -> R {
        let before = self.session.origin.replace(origin);
        let r = f(self);
        self.session.origin = before;
        r
    }

    fn open_link(&mut self, ctx: &egui::Context, url: &str) {
        match &self.services.open_url {
            Some(open) => {
                if let Err(e) = open(url) {
                    self.set_status(format!("Could not open the browser: {e}"), true);
                }
            }
            None => ctx.open_url(egui::OpenUrl::new_tab(url)),
        }
    }
}

/// The consent question and Help › Settings, when open.
pub fn show(app: &mut ModelApp, ctx: &egui::Context) {
    let t = crate::theme::Tokens::get(app.ui.dark);
    match app.prompt {
        Some(Prompt::Consent) => {
            let (mut share, mut decline, mut link) = (false, false, false);
            crate::frame::window(ctx, "Help Improve FieldCraft", crate::frame::Width::Normal).id(egui::Id::new("fc_consent")).show(ctx, |ui| {
                ui.label(QUESTION);
                ui.add_space(4.0);
                ui.label(RichText::new(DETAIL).color(t.text_dim).size(11.0));
                ui.add_space(2.0);
                ui.label(RichText::new("You can change this any time in Help › Settings.").color(t.text_dim).size(11.0));
                link = ui.link("What is sent (docs/privacy.md)").on_hover_text(PRIVACY_URL).clicked();
                ui.add_space(6.0);
                ui.horizontal(|ui| {
                    share = ui.button("Share Anonymous Usage").clicked();
                    decline = ui.button("Don't Share").clicked();
                });
            });
            if link {
                app.open_link(ctx, PRIVACY_URL);
            }
            if share {
                app.answer_consent(true);
            } else if decline || ctx.input(|i| i.key_pressed(egui::Key::Escape)) {
                app.answer_consent(false);
            }
        }
        Some(Prompt::Settings) => {
            let available = app.usage_available();
            let (mut sharing, mut automation) = (app.prefs.usage_sharing == Some(true), app.prefs.usage_automation);
            let (mut close, mut link) = (false, false);
            crate::frame::window(ctx, "Settings", crate::frame::Width::Normal).id(egui::Id::new("fc_settings")).show(ctx, |ui| {
                crate::frame::menu_heading(ui, &t, "PRIVACY");
                ui.add_enabled(available, egui::Checkbox::new(&mut sharing, "Share anonymous usage")).on_hover_text(QUESTION);
                ui.indent("fc_usage_automation", |ui| {
                    ui.add_enabled(available && sharing, egui::Checkbox::new(&mut automation, "Include scripts and AI agents (MCP)"))
                        .on_hover_text("Count the commands scripts, the control channel and AI agents run, apart from yours");
                });
                if !available {
                    ui.label(
                        RichText::new(
                            "This build or run sends nothing: it has no analytics key, or FIELDCRAFT_TELEMETRY=0, CI or automation turned it off.",
                        )
                        .color(t.text_dim)
                        .size(11.0),
                    );
                }
                ui.label(RichText::new(DETAIL).color(t.text_dim).size(11.0));
                ui.label(
                    RichText::new("Crash reports and the log stay on this computer; Help › Report a Bug sends only what you submit.")
                        .color(t.text_dim)
                        .size(11.0),
                );
                link = ui.link("What is sent (docs/privacy.md)").on_hover_text(PRIVACY_URL).clicked();
                ui.add_space(6.0);
                close = ui.button("Close").clicked();
            });
            if available && (sharing != (app.prefs.usage_sharing == Some(true)) || automation != app.prefs.usage_automation) {
                app.set_usage(sharing, automation);
            }
            if link {
                app.open_link(ctx, PRIVACY_URL);
            }
            if close || ctx.input(|i| i.key_pressed(egui::Key::Escape)) {
                app.prompt = None;
            }
        }
        _ => {}
    }
}

#[cfg(test)]
mod tests {
    use fieldcraft_engine::Session;
    use fieldcraft_engine::usage::TEST_LOCK;
    use serde_json::json;

    use super::*;
    use crate::files::{PrefsStore, Services};

    fn host() -> UsageHost {
        UsageHost { platform: "desktop", os: "test", arch: "test", new_id: Box::new(|| Some("11111111-2222-4333-8444-555555555555".into())) }
    }

    fn app(file: &std::path::Path) -> ModelApp {
        ModelApp::new(Session::default()).with_services(Services { prefs: Some(PrefsStore::file(file.to_path_buf())), ..Default::default() })
    }

    fn temp(name: &str) -> std::path::PathBuf {
        let dir = std::env::temp_dir().join(format!("fieldcraft-privacy-{}-{name}", std::process::id()));
        let _ = std::fs::remove_dir_all(&dir);
        std::fs::create_dir_all(&dir).unwrap();
        dir.join("prefs.json")
    }

    /// The first run asks once; nothing is recorded before the answer or after a no, and the
    /// answer is kept: the next run neither asks again nor forgets it.
    #[test]
    fn consent_is_asked_once_and_kept() {
        let _g = TEST_LOCK.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
        usage::disable();
        let file = temp("consent");
        // Without the host's go-ahead (no key, automation, FIELDCRAFT_TELEMETRY=0) nothing asks.
        let mut a = app(&file);
        a.ask_consent();
        assert_eq!(a.prompt, None);

        let mut a = app(&file).with_usage(host());
        a.ask_consent();
        assert_eq!(a.prompt, Some(Prompt::Consent));
        let _ = a.run("model.info", json!({}));
        assert_eq!(usage::queued(), 0, "nothing before the answer");
        a.answer_consent(false);
        assert_eq!(a.prompt, None);
        let _ = a.run("model.info", json!({}));
        assert!(!usage::enabled() && usage::queued() == 0);
        a.ask_consent();
        assert_eq!(a.prompt, None, "asked once");

        let mut again = app(&file).with_usage(host());
        again.ask_consent();
        assert_eq!((again.prompt.clone(), again.prefs.usage_sharing), (None, Some(false)));

        // Settings › Privacy turns it on: the install id is made and kept, and commands count.
        again.set_usage(true, true);
        assert!(usage::enabled());
        let _ = again.run("model.info", json!({}));
        let events: Vec<Event> = std::iter::from_fn(usage::take_batch).flat_map(|b| b.events).collect();
        assert!(events.contains(&Event::AppStarted), "{events:?}");
        assert!(events.iter().any(|e| matches!(e, Event::CommandRun { command: "model.info", from: Origin::Ui, .. })), "{events:?}");
        let kept = crate::files::Prefs::load(Some(&PrefsStore::file(file.clone())));
        assert_eq!((kept.usage_sharing, kept.install_id.as_str()), (Some(true), "11111111-2222-4333-8444-555555555555"));
        usage::disable();
        let _ = std::fs::remove_dir_all(file.parent().unwrap());
    }

    /// A cancelled form and a command clicked before the model is ready are counted, by command
    /// id and the requirements' names; the control channel's are not the user's.
    #[test]
    fn cancelled_forms_and_unavailable_clicks_are_counted() {
        let _g = TEST_LOCK.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
        usage::disable();
        let file = temp("events");
        let mut a = app(&file).with_usage(host());
        a.set_usage(true, true);
        let _ = std::iter::from_fn(usage::take_batch).count();
        let _ = a.start("solve.run");
        a.start("model.material.create").unwrap();
        a.close_dialog();
        a.with_origin(Origin::Script, |a| {
            let _ = a.start("solve.run");
        });
        let events: Vec<Event> = std::iter::from_fn(usage::take_batch).flat_map(|b| b.events).collect();
        let unavailable: Vec<_> = events.iter().filter(|e| matches!(e, Event::UnavailableClicked { command: "solve.run", .. })).collect();
        assert_eq!(unavailable.len(), 1, "{events:?}");
        assert!(events.contains(&Event::FormCancelled { command: "model.material.create" }), "{events:?}");
        assert_eq!(a.session.origin, Some(Origin::Ui));
        usage::disable();
        let _ = std::fs::remove_dir_all(file.parent().unwrap());
    }
}