// registry.bux — package registry index for selfhost (session 81)
// Parity with bootstrap registry.nim: local file + HTTP(S) cache.
module Registry {

    extern func Print(s: String);
    extern func PrintLine(s: String);
    extern func bux_strlen(s: String) -> uint;
    extern func bux_read_file(path: String) -> String;
    extern func bux_write_file(path: String, content: String) -> bool;
    extern func bux_file_exists(path: String) -> int;
    extern func bux_dir_exists(path: String) -> int;
    extern func bux_mkdir_if_needed(path: String) -> int;
    extern func bux_path_join(a: String, b: String) -> String;
    extern func bux_path_parent(path: String) -> String;
    extern func bux_getenv(name: String) -> String;
    extern func bux_getcwd() -> String;
    extern func bux_system(cmd: String) -> int;
    extern func bux_process_output(cmd: String) -> String;

    const REG_MAX: int = 64;

    struct RegistryPackage {
        name: String;
        version: String;
        source: String;
        description: String;
        resolvedPath: String;
    }

    struct Registry {
        path: String;       // local index path (or cache path)
        sourceUrl: String;  // non-empty if from HTTP(S)
        count: int;
        // fixed slots (no dynamic arrays in selfhost compiler easily)
        p0: RegistryPackage;
        p1: RegistryPackage;
        p2: RegistryPackage;
        p3: RegistryPackage;
        p4: RegistryPackage;
        p5: RegistryPackage;
        p6: RegistryPackage;
        p7: RegistryPackage;
        p8: RegistryPackage;
        p9: RegistryPackage;
        p10: RegistryPackage;
        p11: RegistryPackage;
        p12: RegistryPackage;
        p13: RegistryPackage;
        p14: RegistryPackage;
        p15: RegistryPackage;
        // up to 16 packages is enough for smoke/demo; expand if needed
    }

    func Reg_FileExists(path: String) -> bool {
        return bux_file_exists(path) != 0;
    }

    func Reg_DirExists(path: String) -> bool {
        return bux_dir_exists(path) != 0;
    }

    func Reg_IsHttpUrl(s: String) -> bool {
        if String_StartsWith(s, "http://") { return true; }
        if String_StartsWith(s, "https://") { return true; }
        return false;
    }

    func Reg_EnvTruthy(name: String) -> bool {
        let v: String = bux_getenv(name);
        if v == null as String { return false; }
        if String_Eq(v, "") { return false; }
        return true;
    }

    func Reg_HomeCacheDir() -> String {
        let home: String = bux_getenv("HOME");
        if home == null as String || String_Eq(home, "") {
            return ".bux/cache";
        }
        return bux_path_join(bux_path_join(home, ".bux"), "cache");
    }

    func Reg_FetchHttp(url: String) -> String {
        // Download to ~/.bux/cache/registry_http.toml; return local path or "".
        let cacheDir: String = Reg_HomeCacheDir();
        discard bux_mkdir_if_needed(bux_path_join(bux_getenv("HOME"), ".bux"));
        discard bux_mkdir_if_needed(cacheDir);
        let cachePath: String = bux_path_join(cacheDir, "registry_http.toml");
        let metaPath: String = bux_path_join(cacheDir, "registry_http.url");
        let force: bool = Reg_EnvTruthy("BUX_REGISTRY_REFRESH");
        if !force && Reg_FileExists(cachePath) && Reg_FileExists(metaPath) {
            let cachedUrl: String = String_Trim(bux_read_file(metaPath));
            if String_Eq(cachedUrl, url) {
                return cachePath;
            }
        }
        var kflag: String = "";
        if Reg_EnvTruthy("BUX_REGISTRY_INSECURE") {
            kflag = " -k";
        }
        // prefer curl
        let curlCmd: String = String_Concat(
        "curl -fsSL",
        String_Concat(kflag, String_Concat(" --max-time 30 -o \"", String_Concat(cachePath, String_Concat("\" \"", String_Concat(url, "\"")))))
        );
        var ok: bool = false;
        if bux_system("command -v curl >/dev/null 2>&1") == 0 {
            ok = bux_system(curlCmd) == 0 && Reg_FileExists(cachePath);
        } else if bux_system("command -v wget >/dev/null 2>&1") == 0 {
            var nflag: String = "";
            if Reg_EnvTruthy("BUX_REGISTRY_INSECURE") {
                nflag = " --no-check-certificate";
            }
            let wgetCmd: String = String_Concat(
            "wget -q",
            String_Concat(nflag, String_Concat(" -T 30 -O \"", String_Concat(cachePath, String_Concat("\" \"", String_Concat(url, "\"")))))
            );
            ok = bux_system(wgetCmd) == 0 && Reg_FileExists(cachePath);
        }
        if !ok {
            return "";
        }
        discard bux_write_file(metaPath, String_Concat(url, "\n"));
        return cachePath;
    }

    func Reg_StripQuotes(val: String) -> String {
        var v: String = String_Trim(val);
        if String_StartsWith(v, "\"") && String_EndsWith(v, "\"") {
            let n: uint = bux_strlen(v);
            if n >= 2 {
                return String_Slice(v, 1, n - 2);
            }
        }
        return v;
    }

    func Reg_ResolveSource(src: String, indexDir: String) -> String {
        // file: or path: → absolute path; else ""
        var p: String = src;
        if String_StartsWith(src, "file:") {
            p = String_Slice(src, 5, bux_strlen(src) - 5);
            if String_StartsWith(p, "//") {
            p = String_Slice(p, 2, bux_strlen(p) - 2);
        }
    } else if String_StartsWith(src, "path:") {
        p = String_Slice(src, 5, bux_strlen(src) - 5);
    } else {
        return "";
    }
    if String_StartsWith(p, "/") {
        return p;
    }
    return bux_path_join(indexDir, p);
}

func Reg_SetPkg(reg: *Registry, idx: int, pkg: RegistryPackage) {
    if idx == 0 { reg.p0 = pkg; }
    else if idx == 1 { reg.p1 = pkg; }
    else if idx == 2 { reg.p2 = pkg; }
    else if idx == 3 { reg.p3 = pkg; }
    else if idx == 4 { reg.p4 = pkg; }
    else if idx == 5 { reg.p5 = pkg; }
    else if idx == 6 { reg.p6 = pkg; }
    else if idx == 7 { reg.p7 = pkg; }
    else if idx == 8 { reg.p8 = pkg; }
    else if idx == 9 { reg.p9 = pkg; }
    else if idx == 10 { reg.p10 = pkg; }
    else if idx == 11 { reg.p11 = pkg; }
    else if idx == 12 { reg.p12 = pkg; }
    else if idx == 13 { reg.p13 = pkg; }
    else if idx == 14 { reg.p14 = pkg; }
    else if idx == 15 { reg.p15 = pkg; }
}

func Reg_GetPkg(reg: Registry, idx: int) -> RegistryPackage {
    if idx == 0 { return reg.p0; }
    if idx == 1 { return reg.p1; }
    if idx == 2 { return reg.p2; }
    if idx == 3 { return reg.p3; }
    if idx == 4 { return reg.p4; }
    if idx == 5 { return reg.p5; }
    if idx == 6 { return reg.p6; }
    if idx == 7 { return reg.p7; }
    if idx == 8 { return reg.p8; }
    if idx == 9 { return reg.p9; }
    if idx == 10 { return reg.p10; }
    if idx == 11 { return reg.p11; }
    if idx == 12 { return reg.p12; }
    if idx == 13 { return reg.p13; }
    if idx == 14 { return reg.p14; }
    return reg.p15;
}

func Reg_ParseContent(content: String, indexPath: String) -> Registry {
    var reg: Registry;
    reg.path = indexPath;
    reg.sourceUrl = "";
    reg.count = 0;
    let indexDir: String = bux_path_parent(indexPath);
    var cur: RegistryPackage;
    var inPkg: bool = false;
    let nlines: uint = String_SplitCount(content, "\n");
    var i: uint = 0;
    while i <= nlines {
        var line: String = "";
        if i < nlines {
            line = String_Trim(String_SplitPart(content, "\n", i));
        }
        let flush: bool = (i == nlines) || String_Eq(line, "[[package]]") || String_Eq(line, "[[Package]]");
        if flush && inPkg && !String_Eq(cur.name, "") {
            cur.resolvedPath = Reg_ResolveSource(cur.source, indexDir);
            if reg.count < 16 {
                Reg_SetPkg(&reg, reg.count, cur);
                reg.count = reg.count + 1;
            }
            cur.name = "";
            cur.version = "";
            cur.source = "";
            cur.description = "";
            cur.resolvedPath = "";
        }
        if i == nlines { break; }
        if String_Eq(line, "") || String_StartsWith(line, "#") {
            i = i + 1;
            continue;
        }
        if String_Eq(line, "[[package]]") || String_Eq(line, "[[Package]]") {
            inPkg = true;
            i = i + 1;
            continue;
        }
        if !inPkg {
            i = i + 1;
            continue;
        }
        let eqc: uint = String_SplitCount(line, "=");
        if eqc >= 2 {
            let key: String = String_Trim(String_SplitPart(line, "=", 0));
            let val: String = Reg_StripQuotes(String_SplitPart(line, "=", 1));
            // lowercase-ish compare for common keys
            if String_Eq(key, "name") || String_Eq(key, "Name") {
                cur.name = val;
            } else if String_Eq(key, "version") || String_Eq(key, "Version") {
                cur.version = val;
            } else if String_Eq(key, "source") || String_Eq(key, "Source") {
                cur.source = val;
            } else if String_Eq(key, "description") || String_Eq(key, "Description") {
                cur.description = val;
            }
        }
        i = i + 1;
    }
    return reg;
}

func Reg_FindIndex() -> Registry {
    var reg: Registry;
    reg.path = "";
    reg.sourceUrl = "";
    reg.count = 0;
    let env: String = bux_getenv("BUX_REGISTRY");
    if env != null as String && !String_Eq(env, "") {
        if Reg_IsHttpUrl(env) {
            let local: String = Reg_FetchHttp(env);
            if String_Eq(local, "") {
                reg.sourceUrl = env;
                return reg;
            }
            let content: String = bux_read_file(local);
            reg = Reg_ParseContent(content, local);
            reg.sourceUrl = env;
            reg.path = local;
            return reg;
        }
        if Reg_FileExists(env) {
            let content: String = bux_read_file(env);
            reg = Reg_ParseContent(content, env);
            reg.path = env;
            return reg;
        }
    }
    let home: String = bux_getenv("HOME");
    if home != null as String && !String_Eq(home, "") {
        let homeIdx: String = bux_path_join(bux_path_join(home, ".bux"), "registry.toml");
        if Reg_FileExists(homeIdx) {
            let content: String = bux_read_file(homeIdx);
            reg = Reg_ParseContent(content, homeIdx);
            reg.path = homeIdx;
            return reg;
        }
    }
    // cwd-relative candidates
    let cwd: String = bux_getcwd();
    var c0: String = bux_path_join(cwd, "config/registry.toml");
    if Reg_FileExists(c0) {
        let content: String = bux_read_file(c0);
        reg = Reg_ParseContent(content, c0);
        reg.path = c0;
        return reg;
    }
    c0 = bux_path_join(cwd, "../config/registry.toml");
    if Reg_FileExists(c0) {
        let content: String = bux_read_file(c0);
        reg = Reg_ParseContent(content, c0);
        reg.path = c0;
        return reg;
    }
    c0 = bux_path_join(cwd, "../../config/registry.toml");
    if Reg_FileExists(c0) {
        let content: String = bux_read_file(c0);
        reg = Reg_ParseContent(content, c0);
        reg.path = c0;
        return reg;
    }
    return reg;
}

func Reg_VersionOk(have: String, req: String) -> bool {
    if String_Eq(req, "") || String_Eq(req, "*") { return true; }
    return String_Eq(have, req);
}

// Lookup by name; versionReq "*" = last matching entry (highest listed last).
func Reg_Lookup(reg: Registry, name: String, versionReq: String) -> RegistryPackage {
    var found: RegistryPackage;
    found.name = "";
    var i: int = 0;
    while i < reg.count {
        let p: RegistryPackage = Reg_GetPkg(reg, i);
        if String_Eq(p.name, name) && Reg_VersionOk(p.version, versionReq) {
            found = p;
        }
        i = i + 1;
    }
    return found;
}

func Reg_Search(reg: Registry, query: String) -> int {
    // print hits; return count
    var hits: int = 0;
    // Dedupe by name: keep last version
    // Simple O(n^2): for each pkg, if last occurrence of name, print
    var i: int = 0;
    while i < reg.count {
        let p: RegistryPackage = Reg_GetPkg(reg, i);
        var isLast: bool = true;
        var j: int = i + 1;
        while j < reg.count {
            let q: RegistryPackage = Reg_GetPkg(reg, j);
            if String_Eq(q.name, p.name) {
                isLast = false;
                break;
            }
            j = j + 1;
        }
        if isLast {
            var ok: bool = true;
            if !String_Eq(query, "") {
                ok = String_Contains(p.name, query) || String_Contains(p.description, query);
            }
            if ok {
                Print("  ");
                Print(p.name);
                Print("  ");
                Print(p.version);
                Print("  — ");
                if !String_Eq(p.description, "") {
                    PrintLine(p.description);
                } else {
                    PrintLine(p.source);
                }
                hits = hits + 1;
            }
        }
        i = i + 1;
    }
    return hits;
}
}