import { fail } from '@sveltejs/kit';
import { randomUUID } from 'node:crypto';
import { getSessionUser } from '$lib/server/auth/session';
import { requirePermission } from '$lib/server/auth/authorization';
import { getDatabase } from '$lib/server/database';
import { deserializeProposal, refreshProposalDependencies } from '$lib/server/data-moderation';
import { getPagination } from '$lib/server/pagination';
import { recordIsacAudit } from '$lib/server/audit';
import type { Actions, PageServerLoad } from './$types';
import { createNotification } from '$lib/server/notifications';

const statuses = ['pending', 'approved', 'rejected', 'failed'];
const modules = ['configuration', 'calculations', 'attributes', 'talents', 'brands', 'gear', 'weapons', 'weaponmods', 'gearmods', 'protocols', 'skillchips', 'specializations'];
type SerializedEntry =
	| { name: string; kind: 'text'; value: string }
	| { name: string; kind: 'file'; value: string; fileName: string; type: string };

async function specializationProposalSnapshot(database: any, proposal: any) {
	const id = String(proposal.entity_id ?? '');
	if (proposal.action === 'saveProgression') {
		return {
			record: await (await database.prepare("SELECT * FROM specialization_progression_config WHERE id='default'")).get(),
			rankProfiles: await (await database.prepare('SELECT * FROM specialization_rank_cost_profiles ORDER BY rank')).all()
		};
	}
	if (!id) return null;
	if (proposal.action === 'saveSpecialization') {
		return { record: await (await database.prepare('SELECT * FROM specializations WHERE id=?')).get(id) ?? null };
	}
	if (proposal.action === 'saveFocus') {
		return { record: await (await database.prepare('SELECT * FROM specialization_focuses WHERE id=?')).get(id) ?? null };
	}
	if (proposal.action === 'saveAbility') {
		return {
			record: await (await database.prepare('SELECT * FROM specialization_abilities WHERE id=?')).get(id) ?? null,
			effects: await (await database.prepare(
				'SELECT * FROM specialization_ability_effects WHERE ability_id=? ORDER BY effect_order'
			)).all(id)
		};
	}
	if (proposal.action === 'saveCombatEffect') {
		return {
			record: await (await database.prepare('SELECT * FROM specialization_combat_effects WHERE id=?')).get(id) ?? null,
			attachments: await (await database.prepare(
				'SELECT id,node_id,rank,effect_order FROM specialization_tree_rank_combat_effects WHERE combat_effect_id=? ORDER BY node_id,rank,effect_order'
			)).all(id)
		};
	}
	if (proposal.action === 'saveFocusAbilities') {
		return {
			record: await (await database.prepare('SELECT * FROM specialization_focuses WHERE id=?')).get(id) ?? null,
			abilities: await (await database.prepare(
				'SELECT ability_slot,ability_id FROM specialization_focus_abilities WHERE focus_id=? ORDER BY ability_slot'
			)).all(id)
		};
	}
	if (proposal.action === 'saveNode') {
		return {
			record: await (await database.prepare('SELECT * FROM specialization_tree_nodes WHERE id=?')).get(id) ?? null,
			ranks: await (await database.prepare(
				'SELECT * FROM specialization_tree_node_ranks WHERE node_id=? ORDER BY rank'
			)).all(id),
			effects: await (await database.prepare(
				'SELECT * FROM specialization_tree_rank_effects WHERE node_id=? ORDER BY rank,effect_order'
			)).all(id),
			costs: await (await database.prepare(
				'SELECT * FROM specialization_tree_rank_costs WHERE node_id=? ORDER BY rank,resource_id'
			)).all(id),
			combatEffects: await (await database.prepare(
				'SELECT * FROM specialization_tree_rank_combat_effects WHERE node_id=? ORDER BY rank,effect_order'
			)).all(id)
		};
	}
	return null;
}

async function skillChipProposalSnapshot(database: any, id: string) {
	const talent = await (await database.prepare(
		'SELECT * FROM skill_chip_talents WHERE skill_chip_set_id=?'
	)).get(id);
	return {
		record: await (await database.prepare('SELECT * FROM skill_chip_sets WHERE id=?')).get(id) ?? null,
		twoPiece: await (await database.prepare(
			'SELECT * FROM skill_chip_two_piece_bonuses WHERE skill_chip_set_id=?'
		)).get(id) ?? null,
		primaryOptions: await (await database.prepare(
			'SELECT stat_attribute_id FROM skill_chip_primary_options WHERE skill_chip_set_id=? ORDER BY stat_attribute_id'
		)).all(id),
		secondaryOptions: await (await database.prepare(
			'SELECT stat_attribute_id FROM skill_chip_secondary_options WHERE skill_chip_set_id=? ORDER BY stat_attribute_id'
		)).all(id),
		talent: talent ?? null,
		talentTriggers: talent ? await (await database.prepare(
			'SELECT trigger_id FROM skill_chip_talent_triggers WHERE talent_id=? ORDER BY trigger_id'
		)).all(talent.id) : [],
		talentEffects: talent ? await (await database.prepare(
			'SELECT * FROM skill_chip_talent_effects WHERE talent_id=? ORDER BY sort_order'
		)).all(talent.id) : []
	};
}

async function calculationProposalSnapshot(database: any, proposal: any) {
	const id = String(proposal.entity_id ?? '');
	if (!id) return null;
	if (proposal.action === 'saveRevision') return {
		record: await (await database.prepare('SELECT * FROM calculation_revisions WHERE id=?')).get(id) ?? null,
		stages: await (await database.prepare('SELECT * FROM calculation_stages WHERE revision_id=? ORDER BY display_order')).all(id),
		profiles: await (await database.prepare(
			'SELECT * FROM attribute_calculation_profiles WHERE revision_id=? ORDER BY stage_key,stat_attribute_id'
		)).all(id)
	};
	if (proposal.action === 'saveCalibration') return {
		record: await (await database.prepare('SELECT * FROM calculation_calibration_cases WHERE id=?')).get(id) ?? null
	};
	return null;
}

export const load: PageServerLoad = async ({ cookies, url }) => {
	await requirePermission(await getSessionUser(cookies), 'data.approve');
	const database = await getDatabase();
	const status = statuses.includes(url.searchParams.get('status') ?? '') ? String(url.searchParams.get('status')) : 'pending';
	const module = modules.includes(url.searchParams.get('module') ?? '') ? String(url.searchParams.get('module')) : '';
	const search = (url.searchParams.get('search') ?? '').trim().slice(0, 100);
	const conditions = ['p.status=?'];
	const args: unknown[] = [status];
	if (module) { conditions.push('p.module=?'); args.push(module); }
	if (search) { conditions.push("(p.summary LIKE ? ESCAPE '\\' COLLATE NOCASE OR proposer.username LIKE ? ESCAPE '\\' COLLATE NOCASE OR profile.display_name LIKE ? ESCAPE '\\' COLLATE NOCASE)"); const value = `%${search.replaceAll('\\','\\\\').replaceAll('%','\\%').replaceAll('_','\\_')}%`; args.push(value, value, value); }
	const where = `WHERE ${conditions.join(' AND ')}`;
	const total = Number((await (await database.prepare(`SELECT COUNT(*) AS total FROM data_change_proposals p JOIN users proposer ON proposer.id=p.proposed_by LEFT JOIN user_profiles profile ON profile.user_id=proposer.id ${where}`)).get(...args))?.total ?? 0);
	const pagination = getPagination(url, total);
	const proposals = await (await database.prepare(`SELECT p.*,COALESCE(profile.display_name,proposer.username) AS proposer_name,
		COALESCE(reviewer_profile.display_name,reviewer.username) AS reviewer_name
		FROM data_change_proposals p
		JOIN users proposer ON proposer.id=p.proposed_by
		LEFT JOIN user_profiles profile ON profile.user_id=proposer.id
		LEFT JOIN users reviewer ON reviewer.id=p.reviewed_by
		LEFT JOIN user_profiles reviewer_profile ON reviewer_profile.user_id=reviewer.id
		${where} ORDER BY p.created_at DESC LIMIT ? OFFSET ?`)).all(...args, pagination.perPage, pagination.offset);
	const proposalsWithSnapshots = await Promise.all(proposals.map(async (proposal) => ({
		...proposal,
		current_snapshot: proposal.module === 'attributes' && proposal.entity_id
			? await (await database.prepare('SELECT * FROM stat_attributes WHERE id=?')).get(String(proposal.entity_id)) ?? null
			: proposal.module === 'skillchips' && proposal.entity_id
				? await skillChipProposalSnapshot(database, String(proposal.entity_id))
			: proposal.module === 'calculations'
				? await calculationProposalSnapshot(database, proposal)
			: proposal.module === 'specializations'
				? await specializationProposalSnapshot(database, proposal)
				: null
	})));
	const summaryRows = await (await database.prepare('SELECT status,COUNT(*) AS count FROM data_change_proposals GROUP BY status')).all();
	return { proposals: proposalsWithSnapshots, pagination, status, module, search, summary: Object.fromEntries(summaryRows.map((row) => [String(row.status), Number(row.count)])), modules };
};

export const actions: Actions = {
	correct: async ({ cookies, request }) => {
		const reviewer = await requirePermission(await getSessionUser(cookies), 'data.approve');
		const form = await request.formData();
		const id = String(form.get('id') ?? '');
		let corrections: Array<{ index: number; value: string }>;
		try {
			const parsed = JSON.parse(String(form.get('corrections') ?? '[]'));
			if (!Array.isArray(parsed)) throw new Error();
			corrections = parsed.map((item) => ({ index: Number(item.index), value: String(item.value ?? '') }));
		} catch {
			return fail(400, { moderationError: 'The proposed corrections could not be read.' });
		}
		if (corrections.length > 250 || corrections.some((item) => !Number.isInteger(item.index) || item.index < 0 || item.value.length > 100_000)) {
			return fail(400, { moderationError: 'One or more corrected fields exceed the safe proposal limits.' });
		}
		const database = await getDatabase();
		const proposal = await (await database.prepare("SELECT * FROM data_change_proposals WHERE id=? AND status='pending'")).get(id);
		if (!proposal) return fail(404, { moderationError: 'That pending proposal no longer exists.' });
		const entries = JSON.parse(String(proposal.payload_json)) as SerializedEntry[];
		const changes: Array<{ index: number; name: string; before: string; after: string }> = [];
		for (const correction of corrections) {
			const entry = entries[correction.index];
			if (!entry || entry.kind !== 'text') return fail(400, { moderationError: 'Only existing text and numeric proposal fields may be corrected.' });
			if (entry.value !== correction.value) {
				changes.push({ index: correction.index, name: entry.name, before: entry.value, after: correction.value });
				entry.value = correction.value;
			}
		}
		if (!changes.length) return fail(400, { moderationError: 'No proposal fields were changed.' });
		const payload = JSON.stringify(entries);
		const oldDependencies = (await (await database.prepare('SELECT depends_on_proposal_id FROM data_change_proposal_dependencies WHERE proposal_id=? ORDER BY depends_on_proposal_id')).all(id)).map((row) => String(row.depends_on_proposal_id));
		const name = entries.find((entry) => entry.kind === 'text' && entry.name === 'name')?.value.trim();
		const summary = `${String(proposal.action).replace(/([A-Z])/g, ' $1').toUpperCase()} · ${name || proposal.entity_id || 'NEW RECORD'}`;
		await (await database.prepare('UPDATE data_change_proposals SET payload_json=?,summary=? WHERE id=?')).run(payload, summary, id);
		const dependencies = await refreshProposalDependencies(id, payload);
		await recordIsacAudit({
			actorId: reviewer.id,
			category: 'data_moderation',
			action: 'proposal.corrected',
			entityId: id,
			before: { summary: proposal.summary, dependencies: oldDependencies, fields: changes.map((change) => ({ index: change.index, name: change.name, value: change.before })) },
			after: { summary, dependencies, fields: changes.map((change) => ({ index: change.index, name: change.name, value: change.after })) }
		});
		return { moderationSaved: true, moderationToken: randomUUID() };
	},
	approve: async ({ cookies, request, fetch, url }) => {
		const reviewer = await requirePermission(await getSessionUser(cookies), 'data.approve');
		const form = await request.formData();
		const id = String(form.get('id') ?? '');
		const note = String(form.get('note') ?? '').trim().slice(0, 500);
		const database = await getDatabase();
		const proposal = await (await database.prepare("SELECT * FROM data_change_proposals WHERE id=? AND status='pending'")).get(id);
		if (!proposal) return fail(404, { moderationError: 'That pending proposal no longer exists.' });
		const unresolved = await (await database.prepare(`SELECT dependency.id,dependency.summary,dependency.status
			FROM data_change_proposal_dependencies link
			JOIN data_change_proposals dependency ON dependency.id=link.depends_on_proposal_id
			WHERE link.proposal_id=? AND dependency.status<>'approved'`)).all(id);
		if (unresolved.length) {
			const names = unresolved.map((item) => `${item.summary} (${item.status})`).join(', ');
			return fail(409, { moderationError: `Approve this proposal's dependencies first: ${names}.` });
		}
		const target = new URL(`/isac/${proposal.module}?/${proposal.action}`, url.origin);
		const proposalForm = deserializeProposal(String(proposal.payload_json));
		if (proposal.draft_entity_id && !proposal.entity_id) proposalForm.set('_proposedEntityId', String(proposal.draft_entity_id));
		const response = await fetch(target, { method: 'POST', body: proposalForm, headers: { origin: url.origin } });
		const now = new Date().toISOString();
		if (!response.ok) {
			const details = (await response.text()).slice(0, 1000);
			await (await database.prepare("UPDATE data_change_proposals SET status='failed',reviewed_by=?,review_note=?,reviewed_at=? WHERE id=?")).run(reviewer.id, details || note || 'Canonical validation failed.', now, id);
			await recordIsacAudit({ actorId: reviewer.id, category: 'data_moderation', action: 'proposal.failed', entityId: id, before: { status: 'pending' }, after: { status: 'failed', responseStatus: response.status } });
			await createNotification({ userId: String(proposal.proposed_by), category: 'contributions', source: 'ISAC DATA OVERSIGHT', title: 'Contribution could not be deployed', body: `${proposal.summary} did not pass current validation. Oversight evidence is available in your notification inbox.`, link: `/isac/${proposal.module}`, mandatory: true });
			return fail(409, { moderationError: 'The proposal did not pass the current canonical validation and was marked failed.' });
		}
		await (await database.prepare("UPDATE data_change_proposals SET status='approved',applied_entity_id=COALESCE(entity_id,draft_entity_id),reviewed_by=?,review_note=?,reviewed_at=?,applied_at=? WHERE id=?")).run(reviewer.id, note || null, now, now, id);
		await recordIsacAudit({ actorId: reviewer.id, category: 'data_moderation', action: 'proposal.approved', entityId: id, before: { status: 'pending' }, after: { status: 'approved', module: proposal.module, action: proposal.action, proposedBy: proposal.proposed_by, appliedEntityId: proposal.entity_id ?? proposal.draft_entity_id } });
		await createNotification({ userId: String(proposal.proposed_by), category: 'contributions', source: 'ISAC DATA OVERSIGHT', title: 'Contribution approved', body: `${proposal.summary} was approved and deployed to the live builder data set.`, link: `/isac/${proposal.module}`, mandatory: true });
		return { moderationSaved: true, moderationToken: randomUUID() };
	},
	reject: async ({ cookies, request }) => {
		const reviewer = await requirePermission(await getSessionUser(cookies), 'data.approve');
		const form = await request.formData();
		const id = String(form.get('id') ?? '');
		const note = String(form.get('note') ?? '').trim().slice(0, 500);
		if (note.length < 3) return fail(400, { moderationError: 'Add a brief reason for rejecting this proposal.' });
		const database = await getDatabase();
		const proposal = await (await database.prepare("SELECT module,action,proposed_by FROM data_change_proposals WHERE id=? AND status='pending'")).get(id);
		if (!proposal) return fail(404, { moderationError: 'That pending proposal no longer exists.' });
		const now = new Date().toISOString();
		await (await database.prepare("UPDATE data_change_proposals SET status='rejected',reviewed_by=?,review_note=?,reviewed_at=? WHERE id=?")).run(reviewer.id, note, now, id);
		await recordIsacAudit({ actorId: reviewer.id, category: 'data_moderation', action: 'proposal.rejected', entityId: id, before: { status: 'pending' }, after: { status: 'rejected', note, module: proposal.module, action: proposal.action, proposedBy: proposal.proposed_by } });
		await createNotification({ userId: String(proposal.proposed_by), category: 'contributions', source: 'ISAC DATA OVERSIGHT', title: 'Contribution needs revision', body: `${String(proposal.action).replace(/([A-Z])/g, ' $1').trim()} was not approved. Oversight reason: ${note}`, link: `/isac/${proposal.module}`, mandatory: true });
		return { moderationSaved: true, moderationToken: randomUUID() };
	}
};