lowfat-core 0.3.14

use crate::level::Level;
use crate::pipeline::{ConditionalPipelines, parse_conditional_pipeline};
use std::collections::{HashMap, HashSet};
use std::env;
use std::fs;
use std::path::PathBuf;

/// Resolved lowfat configuration from env + .lowfat file.
#[derive(Debug)]
pub struct RunfConfig {
    pub level: Level,
    pub disabled: HashSet<String>,
    /// Some = whitelist mode (only these filters active)
    pub allowed: Option<HashSet<String>>,
    pub data_dir: PathBuf,
    pub plugin_dir: PathBuf,
    pub home_dir: PathBuf,
    /// Per-command conditional pipelines from .lowfat config.
    /// Supports: pipeline.git = ..., pipeline.git.error = ..., pipeline.git.large = ...
    pub pipelines: HashMap<String, ConditionalPipelines>,
}

impl RunfConfig {
    /// Resolve configuration from environment and .lowfat config walking.
    pub fn resolve() -> Self {
        let home_dir = env::var("LOWFAT_HOME")
            .map(PathBuf::from)
            .unwrap_or_else(|_| {
                dirs_home().join(".lowfat")
            });

        let data_dir = env::var("LOWFAT_DATA")
            .map(PathBuf::from)
            .unwrap_or_else(|_| {
                env::var("XDG_DATA_HOME")
                    .map(PathBuf::from)
                    .unwrap_or_else(|_| dirs_home().join(".local/share"))
                    .join("lowfat")
            });

        let plugin_dir = home_dir.join("plugins");

        // Level: LOWFAT_LEVEL env > .lowfat config > default
        let mut level = Level::Full;
        let mut disabled = HashSet::new();
        let mut allowed: Option<HashSet<String>> = None;
        // Collect raw pipeline lines for post-processing into ConditionalPipelines
        // Key: (command, condition) e.g., ("git", "") or ("git", "error")
        let mut pipeline_lines: HashMap<String, Vec<(String, String)>> = HashMap::new();
        let mut pipelines = HashMap::new();

        // Parse .lowfat config (walk up from cwd)
        if let Some(config_path) = find_config() {
            if let Ok(content) = fs::read_to_string(&config_path) {
                for line in content.lines() {
                    let line = line.trim();
                    if line.is_empty() || line.starts_with('#') {
                        continue;
                    }
                    if let Some(val) = line.strip_prefix("level=") {
                        if let Ok(l) = val.parse() {
                            level = l;
                        }
                    } else if let Some(val) = line.strip_prefix("filters=") {
                        allowed = Some(
                            val.split(',').map(|s| s.trim().to_string()).collect(),
                        );
                    } else if let Some(val) = line.strip_prefix("disable=") {
                        for name in val.split(',') {
                            disabled.insert(name.trim().to_string());
                        }
                    } else if let Some(rest) = line.strip_prefix("pipeline.") {
                        // pipeline.git = strip-ansi | git-compact | truncate
                        // pipeline.git.error = strip-ansi | head
                        // pipeline.git.large = git-compact | token-budget
                        if let Some((key, spec)) = rest.split_once('=') {
                            let key = key.trim();
                            let spec = spec.trim().to_string();
                            // Split "git.error" → cmd="git", condition="error"
                            let (cmd, condition) = match key.split_once('.') {
                                Some((c, cond)) => (c.to_string(), cond.to_string()),
                                None => (key.to_string(), String::new()),
                            };
                            pipeline_lines
                                .entry(cmd)
                                .or_default()
                                .push((condition, spec));
                        }
                    }
                }
            }
        }

        // Build ConditionalPipelines from collected lines
        for (cmd, lines) in pipeline_lines {
            pipelines.insert(cmd, parse_conditional_pipeline(&lines));
        }

        // LOWFAT_DISABLE env overrides
        if let Ok(val) = env::var("LOWFAT_DISABLE") {
            for name in val.split(',') {
                disabled.insert(name.trim().to_string());
            }
        }

        // LOWFAT_LEVEL env takes highest priority
        if let Ok(val) = env::var("LOWFAT_LEVEL") {
            if let Ok(l) = val.parse() {
                level = l;
            }
        }

        RunfConfig {
            level,
            disabled,
            allowed,
            data_dir,
            plugin_dir,
            home_dir,
            pipelines,
        }
    }

    /// Get the conditional pipelines for a command, if configured.
    pub fn pipeline_for(&self, cmd: &str) -> Option<&ConditionalPipelines> {
        self.pipelines.get(cmd)
    }

    /// Check if a filter name is enabled under current config.
    pub fn is_enabled(&self, name: &str) -> bool {
        if self.disabled.contains(name) {
            return false;
        }
        if let Some(ref allowed) = self.allowed {
            return allowed.contains(name);
        }
        true
    }
}

/// Walk up from cwd to find nearest `.lowfat` config file.
pub fn find_config() -> Option<PathBuf> {
    let mut dir = env::current_dir().ok()?;
    loop {
        let candidate = dir.join(".lowfat");
        if candidate.is_file() {
            return Some(candidate);
        }
        if !dir.pop() {
            return None;
        }
    }
}

fn dirs_home() -> PathBuf {
    env::var("HOME")
        .map(PathBuf::from)
        .unwrap_or_else(|_| PathBuf::from("/tmp"))
}

/// Find the .lowfat config path (exposed for display purposes).
pub fn find_config_display() -> Option<PathBuf> {
    find_config()
}

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

    #[test]
    fn is_enabled_default() {
        let config = RunfConfig {
            level: Level::Full,
            disabled: HashSet::new(),
            allowed: None,
            data_dir: PathBuf::new(),
            plugin_dir: PathBuf::new(),
            home_dir: PathBuf::new(),
            pipelines: HashMap::new(),
        };
        assert!(config.is_enabled("git"));
        assert!(config.is_enabled("docker"));
    }

    #[test]
    fn is_enabled_disabled() {
        let mut disabled = HashSet::new();
        disabled.insert("npm".to_string());
        let config = RunfConfig {
            level: Level::Full,
            disabled,
            allowed: None,
            data_dir: PathBuf::new(),
            plugin_dir: PathBuf::new(),
            home_dir: PathBuf::new(),
            pipelines: HashMap::new(),
        };
        assert!(!config.is_enabled("npm"));
        assert!(config.is_enabled("git"));
    }

    #[test]
    fn is_enabled_whitelist() {
        let mut allowed = HashSet::new();
        allowed.insert("git".to_string());
        allowed.insert("docker".to_string());
        let config = RunfConfig {
            level: Level::Full,
            disabled: HashSet::new(),
            allowed: Some(allowed),
            data_dir: PathBuf::new(),
            plugin_dir: PathBuf::new(),
            home_dir: PathBuf::new(),
            pipelines: HashMap::new(),
        };
        assert!(config.is_enabled("git"));
        assert!(!config.is_enabled("npm"));
    }
}