using Invercargill;
using Invercargill.DataStructures;
using InvercargillJson;
using Statum;
using Usm;

namespace UsmWeb {

    /** One package row in the overview and single-repo tables. */
    public class PackageRow : Object {
        public string name { get; set; default = ""; }
        public string version { get; set; default = ""; }
        public string summary { get; set; default = ""; }
        public string size { get; set; default = ""; }
        public string file { get; set; default = ""; }
        public string repo { get; set; default = ""; }
    }

    /**
     * One artifact row in a DCBA repository's browse table: the listing
     * entry's name/version plus the page links the row renders — the
     * detail page ({@link href}) and the raw `.dcba` download
     * ({@link download_href}).
     */
    public class ArtifactRow : Object {
        public string name { get; set; default = ""; }
        public string version { get; set; default = ""; }
        public string size { get; set; default = ""; }
        public string file { get; set; default = ""; }
        public string href { get; set; default = ""; }
        public string download_href { get; set; default = ""; }
    }

    /**
     * One repository summary in the overview: the stats card fields plus the
     * per-repository add-repository instruction fields ({@link base_uri},
     * {@link usmr_href}, {@link repos_d_snippet}).
     *
     * Both repository kinds render a card; {@link kind} (the
     * {@link RepositoryKind.to_string} wire name) picks which instruction
     * block and stats the card shows — a USM card carries its package count
     * and byte total, a DCBA card its artifact count and artifact byte
     * total — that total sums the listing's `size` fields, so artifacts
     * from listings written before the field existed (size 0) contribute
     * nothing while still counting toward {@link artifact_count}. The
     * `*_href`/`*_snippet` members are named for the USM card;
     * a DCBA summary fills them with the `repo.dcbar` / `usm dcba
     * add-repo` counterparts so the card markup stays one block with a
     * kind branch.
     */
    public class RepoSummary : Object {
        public string name { get; set; default = ""; }
        public string summary { get; set; default = ""; }
        public string kind { get; set; default = "usm"; }
        public int package_count { get; set; }
        public string total_size { get; set; default = ""; }
        public string href { get; set; default = ""; }
        public string key_fingerprint { get; set; default = ""; }
        public string base_uri { get; set; default = ""; }
        public string usmr_href { get; set; default = ""; }
        public string repos_d_snippet { get; set; default = ""; }
        public int artifact_count { get; set; }
        public string artifact_total_size { get; set; default = ""; }
    }

    /**
     * Authors the `packages` PAGE-slot state shared by the overview and
     * single-repo entrypoints and the search action: repository summaries,
     * the add-repository / install-USM instruction blocks, and the (possibly
     * query-filtered) package table. The lists are authored as JSON arrays
     * because collection-typed GObject properties are write-side only.
     */
    public class PackagesState : Object {

        public const string SLOT_TYPE = "packages";

        /**
         * Builds the slot state: a repo-scoped view when `repo_name` names a
         * repository (its overview card, instruction block and table rows),
         * otherwise the all-repositories overview (summary cards with
         * per-repository add instructions, and one combined table). Rows are
         * filtered by the case-insensitive `query` substring over name and
         * summary (an empty query keeps every entry).
         *
         * The overview lists repositories of **both** kinds as summary
         * cards, in discovery order, but only the USM source repositories
         * feed the package table and the package counts and byte totals —
         * a DCBA entry contributes a card (its artifact count and artifact
         * byte total from the `ARTIFACTS.usml` sizes) and nothing else, so
         * pre-built artifacts surface in the detail views, never in the
         * home package table.
         *
         * A repo-scoped build for a DCBA repository renders that
         * repository's browse view instead: the same overview-card
         * fields (carrying its artifact count and artifact byte total),
         * the `usm dcba add-repo` instruction and one
         * {@link ArtifactRow} per `ARTIFACTS.usml` entry. The query
         * never filters artifacts (search is source-package-only), so
         * those rows ignore `query` entirely and the page omits the
         * search form on the DCBA branch.
         */
        public static State build(RepositoryService repositories, UsmWebConfig config,
                ActionRegistry action_registry, string base_uri, string query, string? repo_name = null) throws Error {
            var repo_rows = new Vector<RepoSummary>();
            var package_rows = new Vector<PackageRow>();
            var dcba_artifact_rows = new Vector<ArtifactRow>();
            int64 total_bytes = 0;
            uint total_count = 0;
            uint matched = 0;

            foreach (var entry in repositories.entries()) {
                var repo = entry.repo();
                if (repo_name != null && repo.name != repo_name) {
                    continue;
                }

                if (entry.kind == RepositoryKind.DCBA) {
                    int64 artifact_bytes = 0;
                    uint artifact_count = 0;
                    var artifact_rows = new Vector<ArtifactRow>();
                    if (repo_name != null) {
                        foreach (var artifact_entry in entry.dcba_listing_entries()) {
                            var file = Path.get_basename(artifact_entry.path);
                            artifact_bytes += (int64) artifact_entry.size;
                            artifact_count++;
                            artifact_rows.add(new ArtifactRow() {
                                name = artifact_entry.name,
                                version = artifact_entry.version,
                                size = artifact_entry.size > 0
                                    ? format_size((int64) artifact_entry.size)
                                    : "?",
                                file = file,
                                href = "/repo/" + repo.name + "/artifact/" + file,
                                download_href = "/repo/" + repo.name + "/" + file
                            });
                        }
                        dcba_artifact_rows.add_all(artifact_rows);
                    } else {
                        foreach (var artifact_entry in entry.dcba_listing_entries()) {
                            artifact_bytes += (int64) artifact_entry.size;
                            artifact_count++;
                        }
                    }

                    repo_rows.add(new RepoSummary() {
                        name = repo.name,
                        summary = repo.summary,
                        kind = RepositoryKind.DCBA.to_string(),
                        artifact_count = (int) artifact_count,
                        artifact_total_size = format_size(artifact_bytes),
                        href = "/repo/" + repo.name,
                        key_fingerprint = fingerprint(repo.key.to_hex()),
                        base_uri = base_uri + "repo/" + repo.name + "/",
                        usmr_href = base_uri + "repo/" + repo.name + "/repo.dcbar",
                        repos_d_snippet = "sudo usm dcba add-repo %srepo/%s/repo.dcbar"
                            .printf(base_uri, repo.name)
                    });
                    continue;
                }

                int64 repo_bytes = 0;
                uint repo_count = 0;
                var rows = new Vector<PackageRow>();
                foreach (var listing_entry in entry.listing_entries()) {
                    var file = Path.get_basename(listing_entry.path);
                    int64 size = file_size(entry.package_location(file));
                    repo_bytes += size;
                    repo_count++;

                    if (!matches(listing_entry, query)) {
                        continue;
                    }
                    rows.add(new PackageRow() {
                        name = listing_entry.manifest.name,
                        version = listing_entry.manifest.version.to_string(),
                        summary = listing_entry.manifest.summary,
                        size = format_size(size),
                        file = file,
                        repo = repo.name
                    });
                }
                matched += rows.length;
                package_rows.add_all(rows);

                repo_rows.add(new RepoSummary() {
                    name = repo.name,
                    summary = repo.summary,
                    kind = RepositoryKind.USM.to_string(),
                    package_count = (int) repo_count,
                    total_size = format_size(repo_bytes),
                    href = "/repo/" + repo.name,
                    key_fingerprint = fingerprint(repo.key.to_hex()),
                    base_uri = base_uri + "repo/" + repo.name + "/",
                    usmr_href = base_uri + "repo/" + repo.name + "/repo.usmr",
                    repos_d_snippet = "sudo usm add-repo %srepo/%s/repo.usmr"
                        .printf(base_uri, repo.name)
                });
                total_bytes += repo_bytes;
                total_count += repo_count;
            }

            if (repo_name != null && repo_rows.length == 0) {
                throw new UsmWebError.INVALID_CONFIGURATION(@"No repository named \"$repo_name\"");
            }

            var dict = new PropertyDictionary();
            if (repo_name == null) {
                dict.set_native<string>("site_name", config.display_name ?? "Repositories");
                dict.set_native<int>("repo_count", (int) repo_rows.length);
                dict.set_native<int>("package_count", (int) total_count);
                dict.set_native<string>("total_size", format_size(total_bytes));
                dict["repos"] = repo_list(repo_rows);
            } else {
                var summary = repo_rows.first();
                dict.set_native<string>("repo_name", summary.name);
                dict.set_native<string>("repo_summary", summary.summary);
                dict.set_native<string>("repo_kind", summary.kind);
                dict.set_native<string>("key_fingerprint", summary.key_fingerprint);
                dict.set_native<int>("package_count", summary.package_count);
                dict.set_native<string>("total_size", summary.total_size);
                dict.set_native<string>("base_uri", summary.base_uri);
                dict.set_native<string>("usmr_href", summary.usmr_href);
                dict.set_native<string>("repos_d_snippet", summary.repos_d_snippet);
                dict.set_native<int>("artifact_count", summary.artifact_count);
                dict.set_native<string>("artifact_total_size", summary.artifact_total_size);
            }
            dict["artifacts"] = artifact_list(dcba_artifact_rows);
            dict.set_native<string>("query", query);
            dict.set_native<string>("result_note", result_note(query, matched, total_count));
            dict.set_native<string>("installer_mode", config.installer.to_string());
            dict.set_native<string>("installer_href", installer_href(config, base_uri));
            dict.set_native<string>("installer_command", installer_command(config, base_uri));
            dict["search"] = action_registry.author<SearchPackagesAction>().to_element();
            dict["packages"] = list(package_rows);

            return new State() {
                type_name = SLOT_TYPE,
                public_data = dict,
                private_data = new PropertyDictionary()
            };
        }

        /** Case-insensitive substring match over name and summary. */
        public static bool matches(RepositoryListingEntry entry, string query) {
            if (query.length == 0) {
                return true;
            }
            var needle = query.casefold();
            return entry.manifest.name.casefold().contains(needle)
                || entry.manifest.summary.casefold().contains(needle);
        }

        /** Builds the package rows' JSON array (the {@link StateJson.list} pattern). */
        public static JsonElement list(Lot<PackageRow> rows) throws Error {
            var arr = new JsonArray();
            foreach (var row in rows) {
                arr.add(new JsonElement.from_properties(GObjectMapping.to_properties(row)));
            }
            return new JsonElement.from_elements(arr);
        }

        /** Builds the artifact rows' JSON array (the same pattern as {@link list}). */
        public static JsonElement artifact_list(Lot<ArtifactRow> rows) throws Error {
            var arr = new JsonArray();
            foreach (var row in rows) {
                arr.add(new JsonElement.from_properties(GObjectMapping.to_properties(row)));
            }
            return new JsonElement.from_elements(arr);
        }

        /** Builds the repository summaries' JSON array. */
        public static JsonElement repo_list(Lot<RepoSummary> rows) throws Error {
            var arr = new JsonArray();
            foreach (var row in rows) {
                arr.add(new JsonElement.from_properties(GObjectMapping.to_properties(row)));
            }
            return new JsonElement.from_elements(arr);
        }

        /** Groups a hex digest into space-separated 16-character chunks. */
        public static string fingerprint(string hex) {
            var builder = new StringBuilder();
            for (int i = 0; i < hex.length; i += 16) {
                if (i > 0) {
                    builder.append_c(' ');
                }
                builder.append(hex[i:int.min(i + 16, hex.length)]);
            }
            return builder.str;
        }

        /** Human-readable byte size (KiB/MiB/GiB). */
        public static string format_size(int64 bytes) {
            if (bytes >= 1073741824) {
                return "%.2f GiB".printf(bytes / 1073741824.0);
            }
            if (bytes >= 1048576) {
                return "%.1f MiB".printf(bytes / 1048576.0);
            }
            if (bytes >= 1024) {
                return "%.1f KiB".printf(bytes / 1024.0);
            }
            return "%lld B".printf(bytes);
        }

        /** The link the install card points at (external URL or this app). */
        private static string installer_href(UsmWebConfig config, string base_uri) {
            if (config.installer == InstallerSource.URL) {
                return (!)config.installer_url;
            }
            return base_uri + "install-usm.sh";
        }

        /** The copy-paste one-liner the install card shows. */
        private static string installer_command(UsmWebConfig config, string base_uri) {
            return "curl -fsSL %s | sh".printf(installer_href(config, base_uri));
        }

        private static string result_note(string query, uint matched, uint total) {
            if (query.length == 0) {
                return "";
            }
            if (matched == 0) {
                return "No packages match \"%s\".".printf(query);
            }
            return "Showing %u of %u packages.".printf(matched, total);
        }

        private static int64 file_size(string path) {
            try {
                var info = File.new_for_path(path).query_info(
                    FileAttribute.STANDARD_SIZE, FileQueryInfoFlags.NONE);
                return info.get_size();
            } catch (Error e) {
                return 0;
            }
        }
    }
}