//
//  AdminLogsView.swift
//  FTStore Admin
//
//  The server's activity log — the same paginated, filterable feed the web
//  dashboard shows, which is usually the fastest way to find out why a build
//  never made it into the feed.
//

import SwiftUI

struct AdminLogsView: View {
	@EnvironmentObject private var session: AdminSession

	@StateObject private var _logs = AdminLoader<AdminActivityResponse>()

	@State private var _search = ""
	@State private var _type: String?
	@State private var _status: String?
	@State private var _page = 1

	private static let _types = ["scan", "download", "process", "generate", "cleanup", "system"]
	private static let _statuses = ["success", "info", "warning", "error"]

	var body: some View {
		List {
			_statsSection

			Section {
				if _logs.isLoading {
					AdminLoadingRow()
				} else if let error = _logs.errorMessage, !_logs.hasLoaded {
					AdminErrorRow(message: error) { Task { await _reload() } }
				} else if let entries = _logs.value?.data, entries.isEmpty {
					AdminEmptyRow(
						icon: "scroll",
						title: "Nothing logged",
						detail: "No entry matches the current filter."
					)
				} else if let entries = _logs.value?.data {
					ForEach(entries) { entry in
						AdminActivityRow(entry: entry)
					}
				}
			} header: {
				if let total = _logs.value?.total {
					Text(
					total == 1
						? String.localized("1 entry")
						: String.localized("%@ entries", AdminFormat.count(total))
				)
				}
			}

			_pagingSection
		}
		.navigationTitle("Logs")
		.navigationBarTitleDisplayMode(.inline)
		.searchable(text: $_search, prompt: "Message contains")
		.refreshable { await _reload() }
		.task { await _reload() }
		.onChange(of: _search) { _ in _resetAndReload() }
		.onChange(of: _type) { _ in _resetAndReload() }
		.onChange(of: _status) { _ in _resetAndReload() }
		.toolbar {
			ToolbarItem(placement: .topBarTrailing) {
				Menu {
					Picker("Type", selection: $_type) {
						Text("All types").tag(String?.none)
						ForEach(Self._types, id: \.self) { type in
							Text(type.capitalized).tag(String?.some(type))
						}
					}
					Divider()
					Picker("Status", selection: $_status) {
						Text("All statuses").tag(String?.none)
						ForEach(Self._statuses, id: \.self) { status in
							Text(status.capitalized).tag(String?.some(status))
						}
					}
				} label: {
					Image(systemName: _type == nil && _status == nil
						? "line.3.horizontal.decrease.circle"
						: "line.3.horizontal.decrease.circle.fill")
				}
			}
		}
	}

	// MARK: Sections

	@ViewBuilder
	private var _statsSection: some View {
		if let stats = _logs.value?.stats, !stats.isEmpty {
			Section {
				HStack(spacing: 8) {
					ForEach(stats.keys.sorted(), id: \.self) { key in
						VStack(spacing: 2) {
							Text(AdminFormat.count(stats[key] ?? 0))
								.font(.subheadline.monospacedDigit())
								.foregroundStyle(AdminStatusPill.tint(for: key))
							Text(key.capitalized)
								.font(.caption2)
								.foregroundStyle(.secondary)
						}
						.frame(maxWidth: .infinity)
					}
				}
				.padding(.vertical, 4)
			}
		}
	}

	@ViewBuilder
	private var _pagingSection: some View {
		if let response = _logs.value, response.totalPages > 1 {
			Section {
				HStack {
					Button("Previous") {
						_page = max(1, _page - 1)
						Task { await _reload() }
					}
					.disabled(_page <= 1)

					Spacer()
					Text("Page \(response.page) of \(response.totalPages)")
						.font(.caption)
						.foregroundStyle(.secondary)
					Spacer()

					Button("Next") {
						_page = min(response.totalPages, _page + 1)
						Task { await _reload() }
					}
					.disabled(_page >= response.totalPages)
				}
				.font(.subheadline)
			}
		}
	}

	// MARK: Loading

	private func _resetAndReload() {
		_page = 1
		Task { await _reload() }
	}

	private func _reload() async {
		var query = ["page": String(_page), "pageSize": "50"]
		if let _type { query["type"] = _type }
		if let _status { query["status"] = _status }
		let needle = _search.trimmingCharacters(in: .whitespaces)
		if !needle.isEmpty { query["search"] = needle }

		await _logs.load {
			try await session.get("/api/dashboard/activity", query: query, as: AdminActivityResponse.self)
		}
	}
}