import { randomUUID } from 'node:crypto';
import type { BlueprintSummary, LaunchRecipeSummary, LaunchFileSummary } from '$lib/deployment-plan.js';
import { config, configFileForGame } from '../config.js';
import { db } from '../db/index.js';
import { zombieMapBySlug, type ZombieGame } from './map-aliases.js';
import { promotedArtifacts } from './promoted-artifacts.js';
import { getPromotedServerConfig, getServerMapConfig, MAP_CONFIG_FILE } from './server-config.js';
import { getBaselineForScope, getVersion, listPromotedOverlaysForScope } from './scripts.js';
import { sha256Buffer } from './files.js';

export interface LaunchRecipe {
    native?: import('../../hosts.js').NativePlacement;
    format: 1;
    game: ZombieGame;
    mapSlug: string;
    mapName: string;
    expectedMap: string;
    capturedAt: string;
    image: string;
    configFile: string;
    configSource: string;
    files: (LaunchFileSummary & { content: string })[];
}

export interface BlueprintEntry { count: number; recipe: LaunchRecipe }
interface BlueprintSelection { count: number; game: ZombieGame; mapSlug: string }
interface BlueprintRow { id: string; name: string; description: string; created_at: string; recipe: string }

/** Legacy snapshots provide the lineup only; their file versions never govern a new launch. */
function readEntries(raw: string): BlueprintSelection[] {
    const saved = JSON.parse(raw) as LaunchRecipe | { format: 2; entries: BlueprintEntry[] }
        | { format: 3; entries: BlueprintSelection[] };
    if (saved.format === 3) return saved.entries;
    const entries = saved.format === 2 ? saved.entries : [{ count: 1, recipe: saved }];
    return entries.map(({ count, recipe }) => ({ count, game: recipe.game, mapSlug: recipe.mapSlug }));
}

function summarizeBlueprint(row: BlueprintRow): BlueprintSummary {
    const entries = readEntries(row.recipe).map(entry => ({ ...entry,
        mapName: zombieMapBySlug(entry.game, entry.mapSlug)?.friendly ?? entry.mapSlug }));
    return { id: row.id, name: row.name, description: row.description, createdAt: row.created_at,
        entries, totalServers: entries.reduce((total, entry) => total + entry.count, 0) };
}

export function blueprintEntries(id: string): { entries: BlueprintEntry[]; blueprintName: string } {
    const row = db().prepare('SELECT * FROM server_blueprints WHERE id = ?').get(id) as BlueprintRow | undefined;
    if (!row) throw new Error('This collection is no longer available. Choose another starting point.');
    const entries = readEntries(row.recipe).map(({ count, game, mapSlug }) => ({ count, recipe: captureRecipe(game, mapSlug) }));
    return { entries, blueprintName: row.name };
}

function buildEntries(input: unknown): BlueprintSelection[] {
    if (!Array.isArray(input) || input.length < 1 || input.length > 40) throw new Error('Add between 1 and 40 map selections.');
    const seen = new Set<string>();
    const entries = input.map(entry => {
        if (!entry || (entry.game !== 't5' && entry.game !== 't6') || typeof entry.mapSlug !== 'string'
            || !zombieMapBySlug(entry.game, entry.mapSlug)) throw new Error('Each selection needs a supported game and map.');
        if (!Number.isSafeInteger(entry.count) || entry.count < 1 || entry.count > 20) throw new Error('Choose 1–20 lobbies for each map.');
        const key = `${entry.game}:${entry.mapSlug}`;
        if (seen.has(key)) throw new Error('Each game/map can appear once. Increase its lobby count instead.');
        seen.add(key);
        return { count: entry.count as number, game: entry.game as ZombieGame, mapSlug: entry.mapSlug as string };
    });
    if (entries.reduce((total, entry) => total + entry.count, 0) > 100) throw new Error('A collection can launch at most 100 servers.');
    return entries;
}

export function captureRecipe(game: ZombieGame, mapSlug: string): LaunchRecipe {
    const map = zombieMapBySlug(game, mapSlug);
    if (!map) throw new Error('Choose a supported game and map.');
    const files: LaunchRecipe['files'] = promotedArtifacts(game, map.canonical).map(({ kind, script, version }) => ({
        name: script.name, kind, path: script.target_rel_path, versionId: version.id,
        version: version.version, sha256: version.sha256, size: version.size, content: version.content.toString('base64')
    }));
    const addConfig = (name: string, path: string, content: Buffer) => files.push({
        name, path, kind: 'config', versionId: null, version: null,
        sha256: sha256Buffer(content), size: content.length, content: content.toString('base64')
    });
    const composed = getPromotedServerConfig(game, map.canonical, map.slug);
    let configSource = 'Plutainer defaults, seeded on first boot';
    if (composed) {
        const baseline = getBaselineForScope('game', game)!;
        const layers = [baseline, ...listPromotedOverlaysForScope('game', game), ...listPromotedOverlaysForScope('map', map.canonical)];
        configSource = layers.map(layer => `${layer.name} v${getVersion(layer.current_version_id!)!.version}`).join(' + ');
        addConfig('Composed server configuration', configFileForGame(game), composed);
    }
    addConfig('Selected map', MAP_CONFIG_FILE, getServerMapConfig(game, map.canonical, map.slug)!);
    return { format: 1, game, mapSlug, mapName: map.friendly, expectedMap: map.canonical,
        capturedAt: new Date().toISOString(), image: config.komodo.defaultImage,
        configFile: configFileForGame(game), configSource, files };
}

export function summarizeRecipe(recipe: LaunchRecipe): LaunchRecipeSummary {
    const { format: _format, files, ...summary } = recipe;
    return { ...summary, files: files.map(({ content: _content, ...file }) => file),
        fingerprint: sha256Buffer(Buffer.from(JSON.stringify(recipe))) };
}

export function recipeForDeployment(id: string): { recipe: LaunchRecipe; blueprintName: string | null } | null {
    const row = db().prepare('SELECT recipe, blueprint_name FROM server_launch_recipes WHERE deployment_id = ?')
        .get(id) as { recipe: string; blueprint_name: string | null } | undefined;
    return row ? { recipe: JSON.parse(row.recipe), blueprintName: row.blueprint_name } : null;
}

export function blueprintRecipe(id: string): { recipe: LaunchRecipe; blueprintName: string } {
    const { entries, blueprintName } = blueprintEntries(id);
    if (entries.length !== 1 || entries[0].count !== 1) throw new Error('This collection launches multiple servers. Use the collection preview.');
    return { recipe: entries[0].recipe, blueprintName };
}

export function listBlueprints(): BlueprintSummary[] {
    return (db().prepare('SELECT * FROM server_blueprints ORDER BY name COLLATE NOCASE').all() as BlueprintRow[]).map(summarizeBlueprint);
}

function blueprintName(input: { name: unknown; description?: unknown }, exceptId = ''): string {
    if (typeof input.name !== 'string' || !input.name.trim() || input.name.trim().length > 80) throw new Error('Give the collection a name of 1–80 characters.');
    if (input.description !== undefined && (typeof input.description !== 'string' || input.description.length > 500)) throw new Error('Keep the description to 500 characters.');
    if (db().prepare('SELECT id FROM server_blueprints WHERE name = ? COLLATE NOCASE AND id != ?').get(input.name.trim(), exceptId)) throw new Error('A collection with this name already exists. Choose a new name.');
    return input.name.trim();
}

export function saveBlueprint(input: { name: unknown; description?: unknown; previewId?: unknown; deploymentId?: unknown; entries?: unknown }): BlueprintSummary {
    const name = blueprintName(input);
    if ([input.previewId, input.deploymentId, input.entries].filter(value => value !== undefined).length !== 1) throw new Error('Choose exactly one launch preview, recorded deployment, or set of maps.');
    let recipe: LaunchRecipe | undefined;
    if (typeof input.previewId === 'string') {
        const row = db().prepare('SELECT recipe FROM server_launch_previews WHERE id = ? AND expires_at > ?')
            .get(input.previewId, new Date().toISOString()) as { recipe: string } | undefined;
        if (row) recipe = JSON.parse(row.recipe);
    } else if (typeof input.deploymentId === 'string') recipe = recipeForDeployment(input.deploymentId)?.recipe;
    if (!recipe && input.entries === undefined) throw new Error('The launch recipe is unavailable or the preview expired. Generate a fresh preview.');
    const entries = input.entries !== undefined ? buildEntries(input.entries)
        : buildEntries([{ count: 1, game: recipe!.game, mapSlug: recipe!.mapSlug }]);
    const id = randomUUID();
    const createdAt = new Date().toISOString();
    const saved = JSON.stringify({ format: 3, entries });
    db().prepare('INSERT INTO server_blueprints (id, name, description, created_at, recipe) VALUES (?, ?, ?, ?, ?)')
        .run(id, name, input.description ?? '', createdAt, saved);
    return summarizeBlueprint({ id, name, description: (input.description as string) ?? '', created_at: createdAt, recipe: saved });
}

export function updateBlueprint(id: string, input: { name: unknown; description?: unknown; entries?: unknown }): BlueprintSummary {
    return db().transaction(() => {
        const row = db().prepare('SELECT * FROM server_blueprints WHERE id = ?').get(id) as BlueprintRow | undefined;
        if (!row) throw new Error('Collection not found.');
        const name = blueprintName(input, id);
        const entries = buildEntries(input.entries);
        const recipe = JSON.stringify({ format: 3, entries });
        const description = (input.description as string) ?? '';
        db().prepare('UPDATE server_blueprints SET name = ?, description = ?, recipe = ? WHERE id = ?').run(name, description, recipe, id);
        return summarizeBlueprint({ ...row, name, description, recipe });
    })();
}

export function deleteBlueprint(id: string): boolean {
    return db().prepare('DELETE FROM server_blueprints WHERE id = ?').run(id).changes > 0;
}