profile-inspect 0.1.3

use std::collections::HashMap;
use std::path::{Component, PathBuf};

use super::{FrameCategory, FrameId, StackId};
use serde::Serialize;

use crate::sourcemap::SourceMapResolver;

/// Normalize path components (resolve .. and . without requiring file to exist)
fn normalize_path_components(path: &PathBuf) -> String {
    let mut components: Vec<Component> = Vec::new();

    for component in path.components() {
        match component {
            Component::ParentDir => {
                // Go up one level if possible
                if let Some(Component::Normal(_)) = components.last() {
                    components.pop();
                } else {
                    components.push(component);
                }
            }
            Component::CurDir => {
                // Skip current dir references
            }
            _ => {
                components.push(component);
            }
        }
    }

    components
        .iter()
        .collect::<PathBuf>()
        .to_string_lossy()
        .to_string()
}

/// A single sample from the profile
///
/// Represents a point in time where the profiler captured the call stack.
/// For CPU profiles, weight is the time delta since the last sample.
/// For heap profiles, weight is the allocation size in bytes.
#[derive(Debug, Clone, Serialize)]
pub struct Sample {
    /// Timestamp in microseconds (from profile start)
    pub timestamp_us: u64,

    /// The call stack at this sample
    pub stack_id: StackId,

    /// Weight of this sample:
    /// - CPU profile: time delta in microseconds
    /// - Heap profile: allocation size in bytes
    pub weight: u64,
}

impl Sample {
    /// Create a new sample
    pub fn new(timestamp_us: u64, stack_id: StackId, weight: u64) -> Self {
        Self {
            timestamp_us,
            stack_id,
            weight,
        }
    }
}

/// The normalized intermediate representation of a profile
///
/// This is the common format that all analyses and outputs work with,
/// regardless of whether the source was a CPU or heap profile.
#[derive(Debug, Clone)]
pub struct ProfileIR {
    /// All unique frames in the profile
    pub frames: Vec<super::Frame>,

    /// All unique stacks in the profile
    pub stacks: Vec<super::Stack>,

    /// All samples in chronological order
    pub samples: Vec<Sample>,

    /// Profile type indicator
    pub profile_type: ProfileType,

    /// Total duration in microseconds (for CPU profiles)
    pub duration_us: Option<u64>,

    /// Source file name
    pub source_file: Option<String>,

    /// Number of frames resolved via sourcemaps
    pub sourcemaps_resolved: usize,

    /// Number of profiles merged (1 = single profile, >1 = merged)
    pub profiles_merged: usize,
}

/// Type of profile
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum ProfileType {
    Cpu,
    Heap,
}

impl ProfileIR {
    /// Create a new CPU profile IR
    pub fn new_cpu(
        frames: Vec<super::Frame>,
        stacks: Vec<super::Stack>,
        samples: Vec<Sample>,
        duration_us: u64,
        source_file: Option<String>,
    ) -> Self {
        Self {
            frames,
            stacks,
            samples,
            profile_type: ProfileType::Cpu,
            duration_us: Some(duration_us),
            source_file,
            sourcemaps_resolved: 0,
            profiles_merged: 1,
        }
    }

    /// Create a new heap profile IR
    pub fn new_heap(
        frames: Vec<super::Frame>,
        stacks: Vec<super::Stack>,
        samples: Vec<Sample>,
        source_file: Option<String>,
    ) -> Self {
        Self {
            frames,
            stacks,
            samples,
            profile_type: ProfileType::Heap,
            duration_us: None,
            source_file,
            sourcemaps_resolved: 0,
            profiles_merged: 1,
        }
    }

    /// Get the total weight of all samples
    pub fn total_weight(&self) -> u64 {
        self.samples.iter().map(|s| s.weight).sum()
    }

    /// Get the number of samples
    pub fn sample_count(&self) -> usize {
        self.samples.len()
    }

    /// Get frame by ID
    pub fn get_frame(&self, id: super::FrameId) -> Option<&super::Frame> {
        self.frames.iter().find(|f| f.id == id)
    }

    /// Get stack by ID
    pub fn get_stack(&self, id: StackId) -> Option<&super::Stack> {
        self.stacks.iter().find(|s| s.id == id)
    }

    /// Resolve frame locations using sourcemaps.
    ///
    /// Returns the number of frames successfully resolved.
    pub fn resolve_sourcemaps(&mut self, sourcemap_dirs: Vec<PathBuf>) -> usize {
        if sourcemap_dirs.is_empty() {
            return 0;
        }

        let mut resolver = SourceMapResolver::new(sourcemap_dirs.clone());
        let mut resolved_count = 0;

        // Use first sourcemap dir as base for resolving relative paths
        // (sourcemap paths are relative to where the .map file is located)
        let base_dir = sourcemap_dirs.first().cloned();

        // Track resolved locations to detect problematic source maps
        let mut location_counts: std::collections::HashMap<String, usize> =
            std::collections::HashMap::new();

        for frame in &mut self.frames {
            // Skip frames without file/line info
            let (Some(file), Some(line), Some(col)) = (&frame.file, frame.line, frame.col) else {
                continue;
            };

            // Try to resolve via sourcemap
            if let Some(resolved) = resolver.resolve(file, line, col) {
                // Store original minified info
                frame.minified_name = Some(frame.name.clone());
                frame.minified_location = Some(frame.location());

                // Update with resolved info
                if let Some(name) = resolved.name {
                    if !name.is_empty() {
                        frame.name = name;
                    }
                }

                // Normalize the resolved file path to absolute
                let normalized_path = Self::normalize_sourcemap_path(&resolved.file, &base_dir);
                frame.file = Some(normalized_path.clone());
                frame.line = Some(resolved.line);
                frame.col = Some(resolved.col);

                // Track this location
                let loc_key = format!("{}:{}", normalized_path, resolved.line);
                *location_counts.entry(loc_key).or_insert(0) += 1;

                // Re-classify category based on new path (e.g., node_modules -> Deps)
                frame.category = Self::classify_category_from_path(&normalized_path);

                resolved_count += 1;
            }
        }

        // Warn if many frames resolve to the same location (indicates problematic source map)
        if resolved_count > 10 {
            for (loc, count) in &location_counts {
                let pct = (*count as f64 / resolved_count as f64) * 100.0;
                if pct > 50.0 && *count > 20 {
                    eprintln!(
                        "  ⚠️  Warning: {} frames ({:.0}%) resolved to same location: {}",
                        count, pct, loc
                    );
                    eprintln!(
                        "     This usually means the source map points to a bundled file, not original sources."
                    );
                    eprintln!(
                        "     Try pointing --sourcemap-dir to a directory with maps to original .ts files."
                    );
                    break;
                }
            }
        }

        self.sourcemaps_resolved = resolved_count;
        resolved_count
    }

    /// Normalize a sourcemap path to an absolute path.
    fn normalize_sourcemap_path(path: &str, base_dir: &Option<PathBuf>) -> String {
        // Strip common URL prefixes
        let path = path
            .strip_prefix("webpack://")
            .or_else(|| path.strip_prefix("webpack:///"))
            .or_else(|| path.strip_prefix("file://"))
            .unwrap_or(path);

        // Remove leading project name in webpack paths (e.g., "project/src/file.ts" -> "src/file.ts")
        let path = if path.contains('/') && !path.starts_with('.') && !path.starts_with('/') {
            // Check if first segment looks like a project name (no extension)
            let first_segment = path.split('/').next().unwrap_or("");
            if !first_segment.contains('.') {
                path.split_once('/').map(|(_, rest)| rest).unwrap_or(path)
            } else {
                path
            }
        } else {
            path
        };

        // If we have a base directory and path is relative, resolve it
        if let Some(base) = base_dir {
            let path_buf = PathBuf::from(path);
            if path_buf.is_relative() {
                let resolved = base.join(&path_buf);
                // Canonicalize to resolve ../ and ./ components
                if let Ok(canonical) = resolved.canonicalize() {
                    return canonical.to_string_lossy().to_string();
                }
                // If canonicalize fails (file doesn't exist), just normalize manually
                return normalize_path_components(&resolved);
            }
        }

        path.to_string()
    }

    /// Re-classify frame category based on resolved path.
    fn classify_category_from_path(path: &str) -> FrameCategory {
        // node_modules -> Dependencies
        if path.contains("node_modules") {
            return FrameCategory::Deps;
        }

        // Node.js internals
        if path.starts_with("node:") || path.contains("internal/") {
            return FrameCategory::NodeInternal;
        }

        // Default to App
        FrameCategory::App
    }

    /// Merge multiple profiles into one.
    ///
    /// Frames are deduplicated by (name, file, line, col).
    /// Stacks are deduplicated by their frame sequence.
    /// Samples from all profiles are combined.
    /// Duration is summed across all profiles.
    pub fn merge(profiles: Vec<Self>) -> Option<Self> {
        if profiles.is_empty() {
            return None;
        }

        if profiles.len() == 1 {
            return profiles.into_iter().next();
        }

        let profile_type = profiles[0].profile_type;

        // Map from (name, file, line, col) -> new FrameId
        let mut frame_key_to_id: HashMap<
            (String, Option<String>, Option<u32>, Option<u32>),
            FrameId,
        > = HashMap::new();
        let mut merged_frames: Vec<super::Frame> = Vec::new();

        // Map from frame sequence -> new StackId
        let mut stack_key_to_id: HashMap<Vec<FrameId>, StackId> = HashMap::new();
        let mut merged_stacks: Vec<super::Stack> = Vec::new();

        let mut merged_samples: Vec<Sample> = Vec::new();
        let mut total_duration: u64 = 0;
        let mut total_sourcemaps_resolved: usize = 0;
        let profiles_count = profiles.len();

        for profile in profiles {
            // Build mapping from old FrameId -> new FrameId for this profile
            let mut frame_id_map: HashMap<FrameId, FrameId> = HashMap::new();

            for frame in &profile.frames {
                let key = (
                    frame.name.clone(),
                    frame.file.clone(),
                    frame.line,
                    frame.col,
                );

                let new_id = *frame_key_to_id.entry(key).or_insert_with(|| {
                    let id = FrameId(merged_frames.len() as u32);
                    let mut new_frame = frame.clone();
                    new_frame.id = id;
                    merged_frames.push(new_frame);
                    id
                });

                frame_id_map.insert(frame.id, new_id);
            }

            // Build mapping from old StackId -> new StackId for this profile
            let mut stack_id_map: HashMap<StackId, StackId> = HashMap::new();

            for stack in &profile.stacks {
                // Remap frame IDs in this stack
                let remapped_frames: Vec<FrameId> = stack
                    .frames
                    .iter()
                    .filter_map(|fid| frame_id_map.get(fid).copied())
                    .collect();

                let new_id = *stack_key_to_id
                    .entry(remapped_frames.clone())
                    .or_insert_with(|| {
                        let id = StackId(merged_stacks.len() as u32);
                        merged_stacks.push(super::Stack::new(id, remapped_frames));
                        id
                    });

                stack_id_map.insert(stack.id, new_id);
            }

            // Remap samples
            for sample in &profile.samples {
                if let Some(&new_stack_id) = stack_id_map.get(&sample.stack_id) {
                    merged_samples.push(Sample {
                        timestamp_us: sample.timestamp_us,
                        stack_id: new_stack_id,
                        weight: sample.weight,
                    });
                }
            }

            if let Some(dur) = profile.duration_us {
                total_duration += dur;
            }
            total_sourcemaps_resolved += profile.sourcemaps_resolved;
        }

        Some(Self {
            frames: merged_frames,
            stacks: merged_stacks,
            samples: merged_samples,
            profile_type,
            duration_us: if total_duration > 0 {
                Some(total_duration)
            } else {
                None
            },
            source_file: Some("(merged)".to_string()),
            sourcemaps_resolved: total_sourcemaps_resolved,
            profiles_merged: profiles_count,
        })
    }
}