use crate::utils::project::get_project_info;
use console::style;
use std::path::Path;

use crate::database::index::{IssueRow, Indexer};
use crate::patterns::Severity;
use crate::utils::config::Config;
use crate::utils::query_cache;
use crate::walk::spawn_senders;

use tree_sitter::{Language, Parser, QueryCursor, StreamingIterator};

#[derive(Debug)]
pub struct Diag {
    pub(crate) path: String,
    pub(crate) line: usize,
    pub(crate) col: usize,
    pub(crate) severity: Severity,
    pub(crate) id: String,
}

/// Entry point called by the CLI.
pub fn handle(
    path: &str,
    no_index: bool,
    rebuild_index: bool,
    format: String,
    high_only: bool,
    database_dir: &Path,
    config: &Config,
) -> Result<(), Box<dyn std::error::Error>> {
    let scan_path = Path::new(path).canonicalize()?;
    let (project_name, db_path) = get_project_info(&scan_path, database_dir)?;
    let diags: Vec<Diag>;
    
    if no_index {
        diags = scan_filesystem(&scan_path, config)?;
    } else {
        if rebuild_index || !db_path.exists() {
            tracing::debug!("Scanning filesystem index filesystem");
            crate::commands::index::build_index(&project_name,&scan_path, &db_path, config)?;
        }

        let mut indexer = Indexer::new(&project_name, &db_path)?;
        diags = scan_with_index(&project_name, &db_path, config, &mut indexer)?;
    }

    if format == "console" || format == "" && config.output.default_format == "console" {
        for d in &diags {
            if high_only && d.severity != Severity::High {
                continue;
            }
            let sev_str = match d.severity {
                Severity::High => style("HIGH").red().bold(),
                Severity::Medium => style("MEDIUM").yellow().bold(),
                Severity::Low => style("LOW").cyan().bold(),
            };
            println!(
                "{}:{}:{}  [{}]  {}",
                style(d.path.clone()).blue().underlined(),
                d.line,
                d.col,
                sev_str,
                style(&d.id).bold(),
            );
        }
    }
    Ok(())
}

// --------------------------------------------------------------------------------------------
// Scanning helpers
// --------------------------------------------------------------------------------------------

fn scan_filesystem(
    root: &Path,
    cfg: &Config,
) -> Result<Vec<Diag>, Box<dyn std::error::Error>> {
    let rx = spawn_senders(root, cfg);
    let mut issues: Vec<Diag> = Vec::new();
    for batch in rx.iter().flatten() {
        issues.append(&mut run_rules_on_file(&batch, cfg)?);
    }
    Ok(issues)
}

fn scan_with_index(
    project: &str,
    _db_path: &Path,
    cfg: &Config,
    indexer: &mut Indexer,
) -> Result<Vec<Diag>, Box<dyn std::error::Error>> {
    let paths = indexer.get_files(project).unwrap_or_default();
    let mut issues: Vec<Diag> = Vec::new();
    for path in paths {
        if indexer.should_scan(&path)? {
            tracing::debug!("scanning files{}", path.display());

            let mut diags = run_rules_on_file(&path, cfg)?;
            let file_id = indexer.upsert_file(&path)?;

            let issue_rows: Vec<IssueRow> = diags
                .iter()
                .map(|d| IssueRow {
                    rule_id: d.id.as_ref(),
                    severity: match d.severity {
                        Severity::High => "HIGH",
                        Severity::Medium => "MEDIUM",
                        Severity::Low => "LOW",
                    },
                    line: d.line as i64,
                    col: d.col as i64,
                })
                .collect();

            indexer.replace_issues(file_id, issue_rows)?;
            issues.append(&mut diags);
            continue;
        }
        issues.append(&mut indexer.get_issues_from_file(&path)?);
    }
    Ok(issues)
}

// --------------------------------------------------------------------------------------------
// Tree‑sitter‑based rule runner – returns a Vec<Diag>
// --------------------------------------------------------------------------------------------
pub(crate) fn run_rules_on_file(
    path: &Path,
    cfg: &Config,
) -> Result<Vec<Diag>, Box<dyn std::error::Error>> {
    let bytes = std::fs::read(path)?;

    let mut parser = Parser::new();

    let lang_key = match path
        .extension()
        .and_then(|s| s.to_str())
        .unwrap_or_default()
        .to_ascii_lowercase()
        .as_str()
    {
        "rs" => (Language::from(tree_sitter_rust::LANGUAGE), "rust"),
        "c" => (Language::from(tree_sitter_c::LANGUAGE), "c"),
        "cpp" | "c++" => (Language::from(tree_sitter_cpp::LANGUAGE), "cpp"),
        "java" => (Language::from(tree_sitter_java::LANGUAGE), "java"),
        "go" => (Language::from(tree_sitter_go::LANGUAGE), "go"),
        "php" => (Language::from(tree_sitter_php::LANGUAGE_PHP), "php"),
        "py" => (Language::from(tree_sitter_python::LANGUAGE), "python"),
        "ts" | "tsx" => (Language::from(tree_sitter_typescript::LANGUAGE_TYPESCRIPT), "typescript"),
        "js" => (Language::from(tree_sitter_javascript::LANGUAGE), "javascript"),
        _ => return Ok(Vec::new()),
    };
    let (ts_lang, lang_name) = lang_key;

    parser.set_language(&ts_lang)?;
    let tree = parser.parse(&*bytes, None).ok_or("tree‑sitter failed")?;
    let root = tree.root_node();

    let compiled = query_cache::for_lang(lang_name, ts_lang);
    let mut cursor = QueryCursor::new();
    let mut out = Vec::new();

    for cq in &compiled {
        if cfg.scanner.min_severity > cq.meta.severity {
            continue;
        }
        let mut matches = cursor.matches(&cq.query, root, &*bytes);
        while let Some(m) = matches.next() {
            for cap in m.captures.iter().filter(|c| c.index == 0) {
                let point = cap.node.start_position();
                out.push(Diag {
                    path: path.to_string_lossy().to_string(),
                    line: point.row + 1,
                    col: point.column + 1,
                    severity: cq.meta.severity,
                    id: String::from(cq.meta.id),
                });
            }
        }
    }
    Ok(out)
}