formualizer-eval 0.8.2

use std::collections::{BTreeMap, BTreeSet};
use std::time::{Duration, Instant};

use formualizer_common::RangeAddress;

use super::{EvaluationBudgets, VertexId};
use crate::formula_plane::region_index::Region;
use crate::formula_plane::runtime::FormulaSpanRef;
use crate::reference::CellRef;

pub type RequestId = u64;

#[cfg(test)]
#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
pub(crate) enum TargetPreparationFault {
    #[default]
    None,
    AfterDiscovery,
    FinalRevisionValidation,
    FinalGraphValidation,
    Admission,
    Reservation,
    BeforeFirstMutation,
}

#[derive(Clone, Debug, PartialEq, Eq, Hash)]
pub enum EvaluationTarget {
    Cell {
        sheet: String,
        row: u32,
        col: u32,
    },
    Range(RangeAddress),
    Name {
        name: String,
        scope_sheet: Option<String>,
    },
    Table {
        name: String,
        selection: TableSelection,
    },
}

#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
pub(crate) enum TargetProducer {
    Legacy(VertexId),
    Span {
        span_ref: FormulaSpanRef,
        demanded: Region,
    },
    Symbol(VertexId),
    ValueOnly(CellRef),
}

#[derive(Clone, Debug, Default, PartialEq, Eq, Hash)]
pub enum TableSelection {
    #[default]
    Whole,
    Headers,
    Data,
    Totals,
    Column(String),
    Columns {
        start: String,
        end: String,
    },
}

#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Hash)]
pub enum OpaquePreparePolicy {
    #[default]
    Widen,
    Error,
}

#[derive(Clone, Debug, Default, PartialEq, Eq, Hash)]
#[non_exhaustive]
pub enum PrepareScope {
    #[default]
    Exact,
    Sheets(Vec<String>),
    Workbook,
}

#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
#[non_exhaustive]
pub enum OpaqueReason {
    DynamicReference,
    RuntimeTextReference,
    UnknownFunction,
    UnknownCustomFunction,
    UnresolvedCrossSheetBinding,
    UnresolvedName,
    UnresolvedTable,
    FormulaName,
    DeferredSourcePackage,
    UnsupportedSourceSemantics,
    UncertainDefaultSheetBinding,
}

/// Controls that apply to a whole target evaluation: preparation *and*
/// evaluation. Cancellation and the deadline are hoisted onto the engine for the
/// duration of the call, so every checkpoint in both phases observes them.
#[derive(Clone, Debug)]
pub struct TargetEvalOptions<'a> {
    pub request_id: Option<RequestId>,
    pub cancel: Option<crate::engine::CancelToken>,
    pub deadline: Option<Instant>,
    pub budgets: Option<&'a EvaluationBudgets>,
    pub opaque_policy: OpaquePreparePolicy,
}

impl Default for TargetEvalOptions<'_> {
    fn default() -> Self {
        Self {
            request_id: None,
            cancel: None,
            deadline: None,
            budgets: None,
            opaque_policy: OpaquePreparePolicy::Widen,
        }
    }
}

#[derive(Clone, Debug, Default, PartialEq, Eq)]
#[non_exhaustive]
pub struct PreparationRevision {
    pub graph: u64,
    /// Raw FormulaPlane epoch. Kept separate from each authority-index counter so
    /// unrelated component revisions cannot collide through arithmetic folding.
    pub authority: u64,
    pub authority_indexes: u64,
    pub authority_indexed_plane: u64,
    pub staged: u64,
    pub symbols: u64,
    pub semantic: u64,
    pub provider: Option<u64>,
}

#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
#[non_exhaustive]
pub enum PreparationOutcome {
    #[default]
    Prepared,
    CompatibilityPrepared,
}

#[derive(Clone, Debug, Default, PartialEq, Eq)]
#[non_exhaustive]
pub struct PreparedTargetGraphReport {
    pub request_id: RequestId,
    pub requested_targets: usize,
    pub normalized_regions: usize,
    pub normalized_target_list: Vec<EvaluationTarget>,
    pub selected_staged_cells: usize,
    /// Total family proposals owned by the whole deferred packages selected by
    /// this request. Selection and consumption are package-atomic.
    pub selected_source_families: usize,
    pub retained_staged_cells: usize,
    pub selected_cells: Vec<RangeAddress>,
    pub retained_cells: Vec<RangeAddress>,
    pub widened_scope: PrepareScope,
    pub widening_reasons: Vec<OpaqueReason>,
    pub revisions: PreparationRevision,
    pub commit_window: Duration,
    pub estimated_scratch_bytes: u64,
    pub observed_scratch_bytes: u64,
    pub estimated_commit_work: u64,
    pub actual_commit_work: u64,
    pub outcome: PreparationOutcome,
}

#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub(crate) struct StagedFormulaLease {
    pub(crate) row: u32,
    pub(crate) col: u32,
    pub(crate) generation: u64,
    pub(crate) insertion_order: u64,
}

#[derive(Clone, Copy, Debug, PartialEq, Eq)]
struct StagedFormulaPresence {
    generation: u64,
    insertion_order: u64,
}

#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub(crate) struct StagedPackageLease {
    pub(crate) generation: u64,
    pub(crate) family_count: usize,
}

#[derive(Clone, Copy, Debug, PartialEq, Eq)]
struct StagedPackageRect {
    start_row: u32,
    start_col: u32,
    end_row: u32,
    end_col: u32,
}

impl StagedPackageRect {
    fn intersects(self, start_row: u32, start_col: u32, end_row: u32, end_col: u32) -> bool {
        self.start_row <= end_row
            && start_row <= self.end_row
            && self.start_col <= end_col
            && start_col <= self.end_col
    }
}

#[derive(Clone, Debug)]
struct StagedPackagePresence {
    generation: u64,
    family_count: usize,
    geometry: Vec<StagedPackageRect>,
    fallback_points: BTreeSet<(u32, u32)>,
    geometry_complete: bool,
}

#[derive(Clone, Debug, Default)]
pub(crate) struct StagedFormulaIndex {
    revision: u64,
    next_generation: u64,
    next_insertion_order: u64,
    sheets: BTreeMap<String, BTreeMap<(u32, u32), StagedFormulaPresence>>,
    packages: BTreeMap<String, StagedPackagePresence>,
}

impl StagedFormulaIndex {
    fn bump(&mut self) {
        self.revision = self
            .revision
            .checked_add(1)
            .expect("staged formula index revision exhausted");
    }

    pub(crate) fn revision(&self) -> u64 {
        self.revision
    }

    pub(crate) fn stage(&mut self, sheet: &str, row: u32, col: u32) {
        let generation = self.next_generation;
        self.next_generation = self
            .next_generation
            .checked_add(1)
            .expect("staged formula generation exhausted");
        let entries = self.sheets.entry(sheet.to_string()).or_default();
        let insertion_order = entries.get(&(row, col)).map_or_else(
            || {
                let order = self.next_insertion_order;
                self.next_insertion_order = self
                    .next_insertion_order
                    .checked_add(1)
                    .expect("staged formula insertion order exhausted");
                order
            },
            |entry| entry.insertion_order,
        );
        entries.insert(
            (row, col),
            StagedFormulaPresence {
                generation,
                insertion_order,
            },
        );
        self.bump();
    }

    pub(crate) fn remove(&mut self, sheet: &str, row: u32, col: u32) -> bool {
        let removed = self
            .sheets
            .get_mut(sheet)
            .is_some_and(|entries| entries.remove(&(row, col)).is_some());
        if self.sheets.get(sheet).is_some_and(BTreeMap::is_empty) {
            self.sheets.remove(sheet);
        }
        if removed {
            self.bump();
        }
        removed
    }

    pub(crate) fn clear_sheet(&mut self, sheet: &str) {
        let changed = self.sheets.remove(sheet).is_some() | self.packages.remove(sheet).is_some();
        if changed {
            self.bump();
        }
    }

    pub(crate) fn clear_all(&mut self) {
        if !self.sheets.is_empty() || !self.packages.is_empty() {
            self.sheets.clear();
            self.packages.clear();
            self.bump();
        }
    }

    pub(crate) fn set_package(
        &mut self,
        sheet: &str,
        package: Option<&super::DeferredFormulaPackage>,
    ) {
        let changed = if let Some(package) = package {
            let generation = self.next_generation;
            self.next_generation = self
                .next_generation
                .checked_add(1)
                .expect("staged package generation exhausted");
            let mut geometry = Vec::new();
            for family in &package.families {
                match &family.members {
                    super::SourceFamilyMembers::CompleteDomain(domain) => {
                        let rect = domain.rect();
                        geometry.push(StagedPackageRect {
                            start_row: rect.start.row.saturating_add(1),
                            start_col: rect.start.col.saturating_add(1),
                            end_row: rect.end.row.saturating_add(1),
                            end_col: rect.end.col.saturating_add(1),
                        });
                    }
                    super::SourceFamilyMembers::ExplicitMembers(members) => {
                        geometry.extend(members.as_slice().iter().map(|coord| StagedPackageRect {
                            start_row: coord.row.saturating_add(1),
                            start_col: coord.col.saturating_add(1),
                            end_row: coord.row.saturating_add(1),
                            end_col: coord.col.saturating_add(1),
                        }));
                    }
                }
            }
            geometry.extend(
                package
                    .partitioned_families
                    .iter()
                    .map(|family| StagedPackageRect {
                        start_row: family.declared.start.row.saturating_add(1),
                        start_col: family.declared.start.col.saturating_add(1),
                        end_row: family.declared.end.row.saturating_add(1),
                        end_col: family.declared.end.col.saturating_add(1),
                    }),
            );
            let fallback_points = package
                .source_coordinates
                .iter()
                .map(|coord| (coord.row.saturating_add(1), coord.col.saturating_add(1)))
                .collect();
            let geometry_complete = package.source_geometry_complete
                || package.report.source_formula_records_spooled == 0;
            self.packages.insert(
                sheet.to_string(),
                StagedPackagePresence {
                    generation,
                    family_count: package.families.len() + package.partitioned_families.len(),
                    geometry,
                    fallback_points,
                    geometry_complete,
                },
            );
            true
        } else {
            self.packages.remove(sheet).is_some()
        };
        if changed {
            self.bump();
        }
    }

    pub(crate) fn touch_package(&mut self, sheet: &str) {
        if let Some(package) = self.packages.get_mut(sheet) {
            package.generation = self.next_generation;
            self.next_generation = self
                .next_generation
                .checked_add(1)
                .expect("staged package generation exhausted");
            self.bump();
        }
    }

    pub(crate) fn has_packages(&self) -> bool {
        !self.packages.is_empty()
    }

    pub(crate) fn package_sheets(&self) -> impl Iterator<Item = &str> {
        self.packages.keys().map(String::as_str)
    }

    pub(crate) fn package_for_region(
        &self,
        sheet: &str,
        start_row: u32,
        start_col: u32,
        end_row: u32,
        end_col: u32,
    ) -> Option<Result<StagedPackageLease, ()>> {
        let package = self.packages.get(sheet)?;
        let intersects = package
            .geometry
            .iter()
            .copied()
            .any(|rect| rect.intersects(start_row, start_col, end_row, end_col))
            || package
                .fallback_points
                .range((start_row, 0)..=(end_row, u32::MAX))
                .any(|&(row, col)| col >= start_col && col <= end_col);
        if intersects {
            Some(Ok(StagedPackageLease {
                generation: package.generation,
                family_count: package.family_count,
            }))
        } else if package.geometry_complete {
            None
        } else {
            Some(Err(()))
        }
    }

    pub(crate) fn package_lease_for_sheet(&self, sheet: &str) -> Option<StagedPackageLease> {
        self.packages.get(sheet).map(|package| StagedPackageLease {
            generation: package.generation,
            family_count: package.family_count,
        })
    }

    pub(crate) fn package_lease_matches(&self, sheet: &str, lease: StagedPackageLease) -> bool {
        self.packages.get(sheet).is_some_and(|package| {
            package.generation == lease.generation && package.family_count == lease.family_count
        })
    }

    pub(crate) fn leases_in_region(
        &self,
        sheet: &str,
        start_row: u32,
        start_col: u32,
        end_row: u32,
        end_col: u32,
    ) -> Vec<StagedFormulaLease> {
        let mut leases = self
            .sheets
            .get(sheet)
            .into_iter()
            .flat_map(|entries| entries.range((start_row, 0)..=(end_row, u32::MAX)))
            .filter_map(|(&(row, col), entry)| {
                (col >= start_col && col <= end_col).then_some(StagedFormulaLease {
                    row,
                    col,
                    generation: entry.generation,
                    insertion_order: entry.insertion_order,
                })
            })
            .collect::<Vec<_>>();
        leases.sort_by_key(|lease| lease.insertion_order);
        leases
    }

    pub(crate) fn leases_for_sheet(&self, sheet: &str) -> Vec<StagedFormulaLease> {
        self.leases_in_region(sheet, 1, 1, u32::MAX, u32::MAX)
    }

    pub(crate) fn all_leases(&self) -> Vec<(String, StagedFormulaLease)> {
        let mut leases = self
            .sheets
            .iter()
            .flat_map(|(sheet, entries)| {
                entries.iter().map(move |(&(row, col), entry)| {
                    (
                        sheet.clone(),
                        StagedFormulaLease {
                            row,
                            col,
                            generation: entry.generation,
                            insertion_order: entry.insertion_order,
                        },
                    )
                })
            })
            .collect::<Vec<_>>();
        leases.sort_by_key(|(_, lease)| lease.insertion_order);
        leases
    }

    pub(crate) fn lease_matches(&self, sheet: &str, lease: StagedFormulaLease) -> bool {
        self.sheets
            .get(sheet)
            .and_then(|entries| entries.get(&(lease.row, lease.col)))
            .is_some_and(|entry| {
                entry.generation == lease.generation
                    && entry.insertion_order == lease.insertion_order
            })
    }

    pub(crate) fn ordinary_count(&self) -> usize {
        self.sheets.values().map(BTreeMap::len).sum()
    }

    #[cfg(test)]
    pub(crate) fn package_count(&self) -> usize {
        self.packages.len()
    }
}

/// Former name of [`TargetEvalOptions`]. The struct governs the whole call, not
/// only preparation, so it was renamed before the name was frozen by a release.
#[deprecated(since = "0.8.0", note = "renamed to TargetEvalOptions")]
pub type PrepareTargetsOptions<'a> = TargetEvalOptions<'a>;