#![forbid(unsafe_code)]
#![allow(clippy::print_stderr, clippy::print_stdout)]
//! `FParkan` command-line tools.

use fparkan_corpus::{discover, render_report_json, report, DiscoverOptions};
use fparkan_inspection::inspect_archive_file;
use fparkan_inspection::ArchiveInspection;
use fparkan_assets::extend_graph_report_with_visual_dependencies;
use fparkan_prototype::build_prototype_graph_report;
use fparkan_resource::{resource_name, CachedResourceRepository};
use fparkan_runtime::{
    create, load_mission, EngineConfig, EngineMode, EngineServices, MissionRequest,
};
use fparkan_vfs::DirectoryVfs;
use std::fmt::Write;
use std::path::PathBuf;
use std::sync::Arc;

fn main() {
    let args: Vec<String> = std::env::args().skip(1).collect();
    let result = run(&args);
    let code = exit_code(&result);
    if let Err(err) = result {
        eprintln!("{err}");
    }
    std::process::exit(code);
}

fn run(args: &[String]) -> Result<(), String> {
    match args {
        [domain, command, rest @ ..] if domain == "corpus" && command == "discover" => {
            let rest = strip_format_json(rest)?;
            let root = parse_root(&rest)?;
            let manifest =
                discover(&root, DiscoverOptions::default()).map_err(|e| e.to_string())?;
            let report = report(&root, &manifest).map_err(|e| e.to_string())?;
            println!("{}", render_report_json(&report));
            Ok(())
        }
        [domain, command, rest @ ..] if domain == "corpus" && command == "validate" => {
            let rest = strip_format_json(rest)?;
            let root = parse_root(&rest)?;
            let manifest =
                discover(&root, DiscoverOptions::default()).map_err(|e| e.to_string())?;
            let report = report(&root, &manifest).map_err(|e| e.to_string())?;
            if report.casefold_collisions > 0 {
                return Err("casefold collisions found".to_string());
            }
            if report.failures > 0 {
                return Err(format!("corpus report found {} failures", report.failures));
            }
            println!("{}", render_report_json(&report));
            Ok(())
        }
        [domain, command, rest @ ..] if domain == "archive" && command == "inspect" => {
            let rest = strip_format_json(rest)?;
            inspect_archive(&rest)
        }
        [domain, command, rest @ ..] if domain == "prototype" && command == "inspect" => {
            let rest = strip_format_json(rest)?;
            inspect_prototype(&rest)
        }
        [domain, command, rest @ ..] if domain == "mission" && command == "graph" => {
            let rest = strip_format_json(rest)?;
            graph_mission(&rest)
        }
        _ => Err(usage()),
    }
}

fn exit_code(result: &Result<(), String>) -> i32 {
    if result.is_ok() {
        0
    } else {
        2
    }
}

fn strip_format_json(args: &[String]) -> Result<Vec<String>, String> {
    let mut stripped = Vec::with_capacity(args.len());
    let mut iter = args.iter();
    while let Some(arg) = iter.next() {
        if arg == "--format" {
            let value = iter
                .next()
                .ok_or_else(|| "--format requires a value".to_string())?;
            if value != "json" {
                return Err(format!("unsupported output format: {value}"));
            }
            continue;
        }
        stripped.push(arg.clone());
    }
    Ok(stripped)
}

fn parse_root(args: &[String]) -> Result<PathBuf, String> {
    let mut iter = args.iter();
    while let Some(arg) = iter.next() {
        if arg == "--root" {
            return iter
                .next()
                .map(PathBuf::from)
                .ok_or_else(|| "--root requires a path".to_string());
        }
    }
    Err("missing --root".to_string())
}

fn parse_root_alias(args: &[String]) -> Result<PathBuf, String> {
    parse_option(args, &["--root", "--game-root"])
        .map(PathBuf::from)
        .ok_or_else(|| "missing --root".to_string())
}

fn parse_required(args: &[String], names: &[&str], label: &str) -> Result<String, String> {
    parse_option(args, names).ok_or_else(|| format!("missing {label}"))
}

fn parse_option(args: &[String], names: &[&str]) -> Option<String> {
    let mut iter = args.iter();
    while let Some(arg) = iter.next() {
        if names.iter().any(|name| arg == name) {
            return iter.next().cloned();
        }
    }
    None
}

fn inspect_prototype(args: &[String]) -> Result<(), String> {
    let root = parse_root_alias(args)?;
    let key = parse_required(args, &["--key"], "--key")?;
    let vfs = Arc::new(DirectoryVfs::new(root));
    let repository = CachedResourceRepository::new(vfs.clone());
    let roots = [resource_name(key.as_bytes())];
    let (graph, resolved, mut report) =
        build_prototype_graph_report(&repository, vfs.as_ref(), &roots);
    extend_graph_report_with_visual_dependencies(
        &repository,
        &mut report,
        &graph,
        &resolved,
    );
    println!("{}", prototype_inspect_json(&key, &graph, &report));
    Ok(())
}

fn prototype_inspect_json(
    key: &str,
    graph: &fparkan_prototype::PrototypeGraph,
    report: &fparkan_prototype::PrototypeGraphReport,
) -> String {
    format!(
        "{{\"schema_version\":\"fparkan-prototype-inspect-v1\",\"key\":{},\"roots\":{},\"prototype_requests\":{},\"resolved\":{},\"unit_references\":{},\"unit_components\":{},\"direct_references\":{},\"wear\":{},\"materials\":{},\"textures\":{},\"lightmaps\":{},\"failures\":{}}}",
        json_string(key),
        report.root_count,
        graph.prototype_requests.len(),
        report.resolved_count,
        report.unit_reference_count,
        report.unit_component_count,
        report.direct_reference_count,
        report.wear_resolved_count,
        report.material_resolved_count,
        report.texture_resolved_count,
        report.lightmap_resolved_count,
        report.failures.len()
    )
}

fn graph_mission(args: &[String]) -> Result<(), String> {
    let root = parse_root_alias(args)?;
    let mission = parse_required(args, &["--mission"], "--mission")?;
    let services = EngineServices::new(Arc::new(DirectoryVfs::new(root)));
    let mut engine = create(
        EngineConfig {
            mode: EngineMode::Headless,
        },
        services,
    )
    .map_err(|err| err.to_string())?;
    let loaded = load_mission(
        &mut engine,
        MissionRequest {
            key: mission.clone(),
        },
    )
    .map_err(|err| err.to_string())?;
    println!(
        "{{\"schema_version\":\"fparkan-mission-graph-v1\",\"mission\":{},\"objects\":{},\"paths\":{},\"clans\":{},\"extras\":{},\"roots\":{},\"direct_references\":{},\"unit_references\":{},\"unit_components\":{},\"prototype_requests\":{},\"wear\":{},\"materials\":{},\"textures\":{},\"lightmaps\":{},\"failures\":{}}}",
        json_string(&mission),
        loaded.object_count,
        loaded.path_count,
        loaded.clan_count,
        loaded.extra_count,
        loaded.graph_root_count,
        loaded.graph_direct_reference_count,
        loaded.graph_unit_reference_count,
        loaded.graph_unit_component_count,
        loaded.graph_resolved_count,
        loaded.graph_wear_resolved_count,
        loaded.graph_material_resolved_count,
        loaded.graph_texture_resolved_count,
        loaded.graph_lightmap_resolved_count,
        loaded.graph_failure_count
    );
    Ok(())
}

fn inspect_archive(args: &[String]) -> Result<(), String> {
    let path = parse_archive_path(args)?;
    let inspection = inspect_archive_file(&path, 0).map_err(|err| err.to_string())?;

    match inspection {
        ArchiveInspection::Nres {
            entries,
            lookup_order_valid,
            ..
        } => {
            println!(
                "{}",
                archive_inspect_json(
                    &path.display().to_string(),
                    "NRes",
                    entries,
                    Some(lookup_order_valid),
                )
            );
            Ok(())
        }
        ArchiveInspection::Rsli { entries } => {
            println!(
                "{}",
                archive_inspect_json(&path.display().to_string(), "RsLi", entries, None)
            );
            Ok(())
        }
        ArchiveInspection::Unsupported => Err(format!("{}: unsupported archive magic", path.display())),
    }
}

fn archive_inspect_json(
    path: &str,
    kind: &str,
    entries: usize,
    lookup_order_valid: Option<bool>,
) -> String {
    let mut out = format!(
        "{{\"schema_version\":\"fparkan-archive-inspect-v1\",\"path\":{},\"kind\":{},\"entries\":{}",
        json_string(path),
        json_string(kind),
        entries
    );
    if let Some(valid) = lookup_order_valid {
        let _ = write!(out, ",\"lookup_order_valid\":{valid}");
    }
    out.push('}');
    out
}

fn parse_archive_path(args: &[String]) -> Result<PathBuf, String> {
    match args {
        [path] => Ok(PathBuf::from(path)),
        [flag, path] if flag == "--file" => Ok(PathBuf::from(path)),
        _ => Err("archive inspect requires <file> or --file <file>".to_string()),
    }
}

fn json_string(value: &str) -> String {
    let mut out = String::with_capacity(value.len() + 2);
    out.push('"');
    for ch in value.chars() {
        match ch {
            '"' => out.push_str("\\\""),
            '\\' => out.push_str("\\\\"),
            '\n' => out.push_str("\\n"),
            '\r' => out.push_str("\\r"),
            '\t' => out.push_str("\\t"),
            c if c.is_control() => {
                let _ = write!(out, "\\u{:04x}", c as u32);
            }
            c => out.push(c),
        }
    }
    out.push('"');
    out
}

fn usage() -> String {
    "usage: fparkan corpus discover|validate --root <path> [--format json] | archive inspect <file> [--format json] | prototype inspect --root <path> --key <key> [--format json] | mission graph --root <path> --mission <path> [--format json]".to_string()
}

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

    fn strings(values: &[&str]) -> Vec<String> {
        values.iter().map(|value| (*value).to_string()).collect()
    }

    #[test]
    fn stable_exit_codes_are_mapped() {
        assert_eq!(exit_code(&Ok(())), 0);
        assert_eq!(exit_code(&Err("failure".to_string())), 2);
    }

    #[test]
    fn accepts_json_format_option() {
        assert_eq!(
            strip_format_json(&strings(&["--root", "testdata", "--format", "json"])),
            Ok(strings(&["--root", "testdata"]))
        );
        assert_eq!(
            strip_format_json(&strings(&["--format", "text"])),
            Err("unsupported output format: text".to_string())
        );
    }

    #[test]
    fn archive_json_has_schema_version() {
        let json = archive_inspect_json("archive.lib", "NRes", 3, Some(true));

        assert!(json.contains("\"schema_version\":\"fparkan-archive-inspect-v1\""));
        assert!(json.contains("\"kind\":\"NRes\""));
        assert!(json.contains("\"lookup_order_valid\":true"));
    }

    #[test]
    fn prototype_graph_json_has_canonical_field_order() {
        let mut graph = fparkan_prototype::PrototypeGraph::default();
        graph
            .prototype_requests
            .push(fparkan_prototype::PrototypeKey(resource_name(b"root")));
        let report = fparkan_prototype::PrototypeGraphReport {
            root_count: 1,
            direct_reference_count: 1,
            resolved_count: 1,
            ..fparkan_prototype::PrototypeGraphReport::default()
        };

        let json = prototype_inspect_json("root", &graph, &report);

        assert_eq!(
            json,
            "{\"schema_version\":\"fparkan-prototype-inspect-v1\",\"key\":\"root\",\"roots\":1,\"prototype_requests\":1,\"resolved\":1,\"unit_references\":0,\"unit_components\":0,\"direct_references\":1,\"wear\":0,\"materials\":0,\"textures\":0,\"lightmaps\":0,\"failures\":0}"
        );
    }
}