use super::*;

#[derive(Clone)]
pub(super) struct PreferenceDraft {
    pub(super) model: ModelChoice,
    pub(super) dspark_enabled: bool,
    pub(super) idle_timeout_minutes: String,
    pub(super) endpoint_port: String,
    pub(super) context_tokens: String,
    pub(super) max_generated_tokens: String,
    pub(super) system_prompt: String,
    pub(super) temperature: String,
    pub(super) top_p: String,
    pub(super) min_p: String,
    pub(super) seed: String,
    pub(super) reasoning_mode: ReasoningMode,
    pub(super) cpu_threads: String,
    pub(super) power_percent: String,
    pub(super) prefill_chunk: String,
    pub(super) quality: bool,
    pub(super) warm_weights: bool,
    pub(super) mtp_draft_tokens: String,
    pub(super) mtp_margin: String,
    pub(super) glm_mtp: bool,
    pub(super) glm_mtp_timing: bool,
    pub(super) dspark_confidence_threshold: String,
    pub(super) dspark_strict: bool,
    pub(super) ssd_streaming: bool,
    pub(super) ssd_streaming_cold: bool,
    pub(super) ssd_cache: String,
    pub(super) ssd_full_layers: String,
    pub(super) ssd_preload_experts: String,
    pub(super) directional_steering_file: String,
    pub(super) directional_steering_ffn: String,
    pub(super) directional_steering_attn: String,
    pub(super) simulated_used_memory_gib: String,
    pub(super) expert_profile_path: String,
}

impl PreferenceDraft {
    pub(super) fn from_saved(preferences: &AppPreferences) -> Result<Self, String> {
        let model = ModelChoice::from_id(&preferences.selected_model)
            .ok_or_else(|| format!("Unsupported model: {}", preferences.selected_model))?;
        let generation = preferences.generation()?;
        let runtime = preferences.runtime()?;
        runtime.validate(model)?;
        let execution = &runtime.execution;
        let speculative = &runtime.speculative;
        Ok(Self {
            model,
            dspark_enabled: speculative.dspark_enabled,
            idle_timeout_minutes: preferences.idle_timeout_minutes.to_string(),
            endpoint_port: preferences.endpoint_port.to_string(),
            context_tokens: generation.context_tokens.to_string(),
            max_generated_tokens: generation.max_generated_tokens.to_string(),
            system_prompt: generation.system_prompt,
            temperature: generation
                .temperature
                .map_or_else(String::new, |value| value.to_string()),
            top_p: generation
                .top_p
                .map_or_else(String::new, |value| value.to_string()),
            min_p: generation
                .min_p
                .map_or_else(String::new, |value| value.to_string()),
            seed: generation
                .seed
                .map_or_else(String::new, |value| value.to_string()),
            reasoning_mode: generation.reasoning_mode,
            cpu_threads: execution
                .cpu_threads
                .map_or_else(String::new, |value| value.to_string()),
            power_percent: execution
                .power_percent
                .map_or_else(String::new, |value| value.to_string()),
            prefill_chunk: execution
                .prefill_chunk
                .map_or_else(String::new, |value| value.to_string()),
            quality: execution.quality,
            warm_weights: execution.warm_weights,
            mtp_draft_tokens: speculative.mtp_draft_tokens.to_string(),
            mtp_margin: speculative.mtp_margin.to_string(),
            glm_mtp: speculative.glm_mtp,
            glm_mtp_timing: speculative.glm_mtp_timing,
            dspark_confidence_threshold: speculative
                .dspark_confidence_threshold
                .map_or_else(String::new, |value| value.to_string()),
            dspark_strict: speculative.dspark_strict,
            ssd_streaming: runtime.ssd.enabled,
            ssd_streaming_cold: runtime.ssd.cold,
            ssd_cache: runtime
                .ssd
                .cache
                .map_or_else(String::new, |cache| match cache {
                    StreamingCacheBudget::Experts(experts) => experts.to_string(),
                    StreamingCacheBudget::Gib(gib) => format!("{gib}GB"),
                }),
            ssd_full_layers: runtime
                .ssd
                .full_layers
                .map_or_else(String::new, |value| value.to_string()),
            ssd_preload_experts: runtime
                .ssd
                .preload_experts
                .map_or_else(String::new, |value| value.to_string()),
            directional_steering_file: runtime.steering.file.unwrap_or_default(),
            directional_steering_ffn: runtime
                .steering
                .ffn_scale
                .map_or_else(String::new, |value| value.to_string()),
            directional_steering_attn: runtime
                .steering
                .attention_scale
                .map_or_else(String::new, |value| value.to_string()),
            simulated_used_memory_gib: runtime
                .diagnostics
                .simulated_used_memory_gib
                .map_or_else(String::new, |value| value.to_string()),
            expert_profile_path: runtime.diagnostics.expert_profile_path.unwrap_or_default(),
        })
    }

    pub(super) fn generation(&self) -> Result<GenerationPreferences, String> {
        let preferences = GenerationPreferences {
            context_tokens: parse_positive_i32("Context tokens", &self.context_tokens)?,
            max_generated_tokens: parse_positive_i32(
                "Maximum generated tokens",
                &self.max_generated_tokens,
            )?,
            system_prompt: self.system_prompt.clone(),
            temperature: parse_optional_f32("Temperature", &self.temperature)?,
            top_p: parse_optional_f32("Top-p", &self.top_p)?,
            min_p: parse_optional_f32("Min-p", &self.min_p)?,
            seed: parse_optional_u64("Seed", &self.seed)?,
            reasoning_mode: self.reasoning_mode,
        };
        preferences.validate()?;
        Ok(preferences)
    }

    pub(super) fn reset(&mut self) {
        let defaults = GenerationPreferences::default();
        let execution = ExecutionPreferences::default();
        let speculative = SpeculativePreferences::default();
        let ssd = SsdPreferences::default();
        self.model = ModelChoice::default();
        self.dspark_enabled = false;
        self.idle_timeout_minutes = "10".into();
        self.endpoint_port = "4000".into();
        self.context_tokens = defaults.context_tokens.to_string();
        self.max_generated_tokens = defaults.max_generated_tokens.to_string();
        self.system_prompt = defaults.system_prompt;
        self.temperature.clear();
        self.top_p.clear();
        self.min_p.clear();
        self.seed.clear();
        self.reasoning_mode = defaults.reasoning_mode;
        self.cpu_threads.clear();
        self.power_percent.clear();
        self.prefill_chunk.clear();
        self.quality = execution.quality;
        self.warm_weights = execution.warm_weights;
        self.mtp_draft_tokens = speculative.mtp_draft_tokens.to_string();
        self.mtp_margin = speculative.mtp_margin.to_string();
        self.glm_mtp = speculative.glm_mtp;
        self.glm_mtp_timing = speculative.glm_mtp_timing;
        self.dspark_confidence_threshold.clear();
        self.dspark_strict = speculative.dspark_strict;
        self.ssd_streaming = ssd.enabled;
        self.ssd_streaming_cold = ssd.cold;
        self.ssd_cache.clear();
        self.ssd_full_layers.clear();
        self.ssd_preload_experts.clear();
        self.directional_steering_file.clear();
        self.directional_steering_ffn.clear();
        self.directional_steering_attn.clear();
        self.simulated_used_memory_gib.clear();
        self.expert_profile_path.clear();
    }

    pub(super) fn execution(&self) -> Result<ExecutionPreferences, String> {
        Ok(ExecutionPreferences {
            cpu_threads: parse_optional_u32("CPU helper threads", &self.cpu_threads)?,
            power_percent: parse_optional_u8("GPU power", &self.power_percent)?,
            prefill_chunk: parse_optional_u32("Prefill chunk", &self.prefill_chunk)?,
            quality: self.quality,
            warm_weights: self.warm_weights,
        })
    }

    pub(super) fn speculative(&self) -> Result<SpeculativePreferences, String> {
        Ok(SpeculativePreferences {
            mtp_draft_tokens: parse_positive_i32("MTP draft tokens", &self.mtp_draft_tokens)?,
            mtp_margin: parse_f32("MTP margin", &self.mtp_margin)?,
            glm_mtp: self.glm_mtp,
            glm_mtp_timing: self.glm_mtp_timing,
            dspark_enabled: self.dspark_enabled,
            dspark_confidence_threshold: parse_optional_f32(
                "DSpark confidence",
                &self.dspark_confidence_threshold,
            )?,
            dspark_strict: self.dspark_strict,
        })
    }

    pub(super) fn runtime(&self) -> Result<RuntimePreferences, String> {
        Ok(RuntimePreferences {
            execution: self.execution()?,
            speculative: self.speculative()?,
            ssd: SsdPreferences {
                enabled: self.ssd_streaming,
                cold: self.ssd_streaming_cold,
                cache: parse_streaming_cache(&self.ssd_cache)?,
                full_layers: parse_optional_u32("SSD full-layer count", &self.ssd_full_layers)?,
                preload_experts: parse_optional_u32(
                    "SSD preload experts",
                    &self.ssd_preload_experts,
                )?,
            },
            steering: SteeringPreferences {
                file: optional_text(&self.directional_steering_file),
                ffn_scale: parse_optional_f32(
                    "Directional FFN scale",
                    &self.directional_steering_ffn,
                )?,
                attention_scale: parse_optional_f32(
                    "Directional attention scale",
                    &self.directional_steering_attn,
                )?,
            },
            diagnostics: DiagnosticPreferences {
                simulated_used_memory_gib: parse_optional_gib(
                    "Simulated used memory",
                    &self.simulated_used_memory_gib,
                )?,
                expert_profile_path: optional_text(&self.expert_profile_path),
            },
        })
    }
}

fn parse_positive_i32(name: &str, value: &str) -> Result<i32, String> {
    value
        .trim()
        .parse::<i32>()
        .ok()
        .filter(|value| *value > 0)
        .ok_or_else(|| format!("{name} must be a positive whole number."))
}

fn parse_optional_f32(name: &str, value: &str) -> Result<Option<f32>, String> {
    let value = value.trim();
    if value.is_empty() {
        Ok(None)
    } else {
        value
            .parse()
            .map(Some)
            .map_err(|_| format!("{name} must be a number or left blank for the DS4 default."))
    }
}

fn parse_f32(name: &str, value: &str) -> Result<f32, String> {
    value
        .trim()
        .parse()
        .map_err(|_| format!("{name} must be a number."))
}

fn parse_optional_u64(name: &str, value: &str) -> Result<Option<u64>, String> {
    let value = value.trim();
    if value.is_empty() {
        Ok(None)
    } else {
        value
            .parse()
            .map(Some)
            .map_err(|_| format!("{name} must be a positive whole number or left blank."))
    }
}

fn parse_optional_u32(name: &str, value: &str) -> Result<Option<u32>, String> {
    parse_optional_number(name, value)
}

fn parse_optional_u8(name: &str, value: &str) -> Result<Option<u8>, String> {
    parse_optional_number(name, value)
}

fn parse_optional_number<T: std::str::FromStr>(
    name: &str,
    value: &str,
) -> Result<Option<T>, String> {
    let value = value.trim();
    if value.is_empty() {
        Ok(None)
    } else {
        value
            .parse()
            .map(Some)
            .map_err(|_| format!("{name} must be a positive whole number or left blank."))
    }
}

pub(super) fn parse_streaming_cache(value: &str) -> Result<Option<StreamingCacheBudget>, String> {
    let value = value.trim();
    if value.is_empty() {
        return Ok(None);
    }
    if value.len() > 2
        && value
            .get(value.len() - 2..)
            .is_some_and(|suffix| suffix.eq_ignore_ascii_case("gb"))
    {
        return parse_gib("SSD cache budget", value)
            .map(|gib| Some(StreamingCacheBudget::Gib(gib)));
    }
    if !value.chars().all(|character| character.is_ascii_digit()) {
        return Err(
            "SSD cache budget must be a positive expert count or whole GiB value such as 64GB."
                .into(),
        );
    }
    value
        .parse::<u32>()
        .ok()
        .filter(|value| *value > 0)
        .map(StreamingCacheBudget::Experts)
        .map(Some)
        .ok_or_else(|| {
            "SSD cache budget must be a positive expert count or whole GiB value such as 64GB."
                .into()
        })
}

pub(super) fn parse_optional_gib(name: &str, value: &str) -> Result<Option<u64>, String> {
    let value = value.trim();
    if value.is_empty() {
        Ok(None)
    } else {
        parse_gib(name, value).map(Some)
    }
}

fn parse_gib(name: &str, value: &str) -> Result<u64, String> {
    let value = value
        .get(value.len().saturating_sub(2)..)
        .filter(|suffix| suffix.eq_ignore_ascii_case("gb"))
        .map_or(value, |_| &value[..value.len() - 2]);
    if !value.chars().all(|character| character.is_ascii_digit()) {
        return Err(format!("{name} must be a positive whole GiB value."));
    }
    value
        .parse::<u64>()
        .ok()
        .filter(|value| *value > 0 && *value <= u64::MAX / GIB)
        .ok_or_else(|| format!("{name} must be a positive whole GiB value."))
}

fn optional_text(value: &str) -> Option<String> {
    let value = value.trim();
    (!value.is_empty()).then(|| value.to_owned())
}

fn update_runtime_preferences(
    runtime_preferences: &RwLock<AppPreferences>,
    preferences: &AppPreferences,
) {
    *runtime_preferences
        .write()
        .unwrap_or_else(|poisoned| poisoned.into_inner()) = preferences.clone();
}

impl App {
    pub(super) fn open_preferences(&mut self) {
        if self.database.is_none() || self.pending_project_path.is_some() || self.choosing_folder {
            return;
        }
        match PreferenceDraft::from_saved(&self.preferences) {
            Ok(draft) => {
                self.preference_draft = draft;
                self.preference_error = None;
                self.preferences_open = true;
            }
            Err(error) => self.error = Some(error),
        }
    }

    pub(super) fn save_preferences(&mut self) {
        let Ok(idle_timeout_minutes) = self
            .preference_draft
            .idle_timeout_minutes
            .trim()
            .parse::<i32>()
        else {
            self.preference_error = Some("Idle timeout must be a whole number.".into());
            return;
        };
        if !(1..=1440).contains(&idle_timeout_minutes) {
            self.preference_error = Some("Idle timeout must be between 1 and 1440 minutes.".into());
            return;
        }
        let Ok(endpoint_port) = self.preference_draft.endpoint_port.trim().parse::<u16>() else {
            self.preference_error = Some("Endpoint port must be a whole number.".into());
            return;
        };
        if endpoint_port == 0 {
            self.preference_error = Some("Endpoint port must be between 1 and 65535.".into());
            return;
        }
        let generation = match self.preference_draft.generation() {
            Ok(generation) => generation,
            Err(error) => {
                self.preference_error = Some(error);
                return;
            }
        };

        let model = self.preference_draft.model;
        let runtime = match self.preference_draft.runtime() {
            Ok(runtime) => runtime,
            Err(error) => {
                self.preference_error = Some(error);
                return;
            }
        };
        if let Err(error) = runtime.validate(model) {
            self.preference_error = Some(error);
            return;
        }
        #[cfg(target_os = "macos")]
        let pending_endpoint = if self.preferences.endpoint_port != i32::from(endpoint_port)
            || self._endpoint.is_none()
        {
            let Some(generation) = &self.generation_service else {
                self.preference_error = Some("The model runtime is unavailable.".into());
                return;
            };
            match crate::server::ServerHandle::spawn(
                generation.clone(),
                Arc::clone(&self.runtime_preferences),
                models_path(),
                application_support_path().join("kv-cache").join("http"),
                endpoint_port,
                Arc::clone(&self.metrics),
            ) {
                Ok(endpoint) => Some(endpoint),
                Err(error) => {
                    self.preference_error = Some(error);
                    return;
                }
            }
        } else {
            None
        };
        let Some(database) = &mut self.database else {
            return;
        };
        match database.update_preferences(
            model.id(),
            idle_timeout_minutes,
            i32::from(endpoint_port),
            &generation,
            &runtime,
        ) {
            Ok(preferences) => {
                self.preferences = preferences;
                #[cfg(target_os = "macos")]
                update_runtime_preferences(&self.runtime_preferences, &self.preferences);
                #[cfg(target_os = "macos")]
                if let Some(endpoint) = pending_endpoint {
                    self._endpoint = Some(endpoint);
                }
                self.preference_draft = PreferenceDraft::from_saved(&self.preferences)
                    .expect("the saved model was selected from the supported catalog");
                self.preferences_open = false;
                self.preference_error = None;
                self.error = None;
            }
            Err(error) => self.preference_error = Some(error),
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn runtime_preferences_update_after_lock_poisoning() {
        let runtime = Arc::new(RwLock::new(AppPreferences::default()));
        let poisoned = Arc::clone(&runtime);
        let _ = std::thread::spawn(move || {
            let _guard = poisoned.write().unwrap();
            panic!("poison preference lock");
        })
        .join();
        let preferences = AppPreferences {
            endpoint_port: 4567,
            ..AppPreferences::default()
        };

        update_runtime_preferences(&runtime, &preferences);

        assert_eq!(
            runtime
                .read()
                .unwrap_or_else(|poisoned| poisoned.into_inner())
                .endpoint_port,
            4567
        );
    }
}