// BuildService.swift
// All shared models (FileNode, ConnectedDevice, ConsoleLine, etc.)
// live in Shared/SharedModels.swift — do not redeclare them here.

import Foundation
import Combine
import SwiftUI

@MainActor
final class BuildService: ObservableObject {

    @Published var fileTree:     FileNode?
    @Published var devices:      [ConnectedDevice] = []
    @Published var consoleLines: [ConsoleLine] = []
    @Published var isBuilding:   Bool = false
    @Published var errorMessage: String?

    let historyStore   = BuildHistoryStore()
    let healthMonitor: DaemonHealthMonitor

    let config: DaemonConfiguration

    private var webSocketTask:     URLSessionWebSocketTask?
    private var buildStartTime:    Date?
    private var currentBuildRecord: PartialBuildRecord?

    private struct PartialBuildRecord {
        let id            = UUID()
        let projectName:  String
        let scheme:       String
        let action:       String
        let configuration: String
        let destination:  String
        var errorCount    = 0
        var warningCount  = 0
        var logBuffer     = ""
    }

    init(config: DaemonConfiguration) {
        self.config        = config
        self.healthMonitor = DaemonHealthMonitor(config: config)
        healthMonitor.onReconnected  = { [weak self] in await self?.onDaemonReconnected() }
        healthMonitor.onDisconnected = { [weak self] in self?.handleDaemonDisconnected() }
        healthMonitor.startPolling()
    }

    // MARK: - File Tree

    func fetchFileTree(projectPath: String) async {
        guard let url = URL(string: "\(config.baseURL)/files/tree?path=\(projectPath.urlEncoded)") else { return }
        do {
            let (data, _) = try await URLSession.shared.data(from: url)
            fileTree = try JSONDecoder().decode(FileNode.self, from: data)
        } catch {
            errorMessage = "File tree: \(error.localizedDescription)"
        }
    }

    // MARK: - File Content

    func fetchFileContent(path: String) async -> String? {
        guard let url = URL(string: "\(config.baseURL)/files/content?path=\(path.urlEncoded)") else { return nil }
        do {
            let (data, _) = try await URLSession.shared.data(from: url)
            return try JSONDecoder().decode(FileContentResponse.self, from: data).content
        } catch {
            errorMessage = "Load file: \(error.localizedDescription)"
            return nil
        }
    }

    // MARK: - File Save

    func saveFile(path: String, content: String) async {
        do {
            try FileOperationValidator.validateSave(path: path, content: content)
        } catch {
            appendConsole("⚠️ \(error.localizedDescription)", type: .warning)
            return
        }
        do {
            try await withRetry(policy: .fileSave) {
                guard let url = URL(string: "\(self.config.baseURL)/files/save") else {
                    throw URLError(.badURL)
                }
                let body: [String: String] = ["path": path, "content": content]
                guard let data = try? JSONEncoder().encode(body) else { throw URLError(.cannotDecodeContentData) }
                var req = URLRequest(url: url)
                req.httpMethod = "PUT"
                req.setValue("application/json", forHTTPHeaderField: "Content-Type")
                req.httpBody = data
                req.timeoutInterval = 8
                let (_, resp) = try await URLSession.shared.data(for: req)
                guard (resp as? HTTPURLResponse)?.statusCode == 204 else { throw URLError(.badServerResponse) }
            }
        } catch {
            appendConsole("❌ Save failed: \(error.localizedDescription)", type: .error)
            ToastStore.shared.show("Save failed", style: .error)
        }
    }

    // MARK: - Devices

    func fetchDevices() async {
        guard let url = URL(string: "\(config.baseURL)/devices/list") else { return }
        do {
            let (data, _) = try await URLSession.shared.data(from: url)
            devices = try JSONDecoder().decode([ConnectedDevice].self, from: data)
        } catch {
            errorMessage = "Devices: \(error.localizedDescription)"
        }
    }

    // MARK: - Build

    func startBuild(
        projectPath:      String,
        scheme:           String,
        selectedDevice:   ConnectedDevice?,
        action:           String = "build",
        preBuildHooks:    [PreBuildHookRequest] = [],
        bundleIdentifier: String? = nil
    ) async {
        guard !isBuilding else { return }
        isBuilding     = true
        buildStartTime = Date()
        consoleLines   = []

        let destination:      String
        let destinationLabel: String

        if let device = selectedDevice {
            destination      = "platform=iOS,id=\(device.udid)"
            destinationLabel = "\(device.name) (\(device.osVersion))"
        } else {
            destination      = ""
            destinationLabel = "Build Only"
        }

        let resolvedAction = (selectedDevice == nil) ? "build" : action

        if selectedDevice == nil && action == "buildAndRun" {
            appendConsole("⚠️  No device selected — building without deploying.", type: .warning)
        }

        currentBuildRecord = PartialBuildRecord(
            projectName:   URL(fileURLWithPath: projectPath).lastPathComponent,
            scheme:        scheme,
            action:        resolvedAction,
            configuration: config.buildConfiguration,
            destination:   destinationLabel
        )

        let buildReq = BuildRequest(
            projectPath:        projectPath,
            scheme:             scheme,
            destination:        destination,
            action:             resolvedAction,
            configuration:      config.buildConfiguration,
            preBuildHooks:      preBuildHooks,
            bundleIdentifier:   bundleIdentifier,
            extraBuildSettings: []
        )

        guard let url = URL(string: "\(config.baseURL)/build/start"),
              let bodyData = try? JSONEncoder().encode(buildReq) else {
            isBuilding = false; return
        }

        var request = URLRequest(url: url)
        request.httpMethod = "POST"
        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
        request.httpBody = bodyData

        do {
            let (data, _) = try await URLSession.shared.data(for: request)
            let session   = try JSONDecoder().decode(BuildSessionResponse.self, from: data)
            await connectBuildStream(webSocketURL: session.webSocketURL)
        } catch {
            appendConsole("❌ Failed to reach daemon: \(error.localizedDescription)", type: .error)
            isBuilding = false
            commitBuildRecord(outcome: .failure)
        }
    }

    // MARK: - WebSocket

    private func connectBuildStream(webSocketURL: String) async {
        guard let url = URL(string: webSocketURL) else { return }
        webSocketTask?.cancel()
        webSocketTask = URLSession.shared.webSocketTask(with: url)
        webSocketTask?.resume()
        appendConsole("🔌 Connected to build stream.", type: .info)
        await receiveLoop()
    }

    private func receiveLoop() async {
        guard let task = webSocketTask, task.state == .running else {
            isBuilding = false; return
        }
        do {
            let message = try await task.receive()
            switch message {
            case .string(let text): handleIncomingLog(text)
            case .data(let data):
                if let text = String(data: data, encoding: .utf8) { handleIncomingLog(text) }
            @unknown default: break
            }
            await receiveLoop()
        } catch {
            isBuilding = false
            commitBuildRecord(outcome: .failure)
        }
    }

    private func handleIncomingLog(_ text: String) {
        guard let data = text.data(using: .utf8),
              let msg  = try? JSONDecoder().decode(BuildLogMessage.self, from: data) else {
            appendConsole(text, type: .standard); return
        }
        let newLines = ConsoleLine.fromBuildLogMessage(msg)
        consoleLines.append(contentsOf: newLines)
        if var rec = currentBuildRecord {
            rec.errorCount   += newLines.filter { $0.type == .error   }.count
            rec.warningCount += newLines.filter { $0.type == .warning }.count
            rec.logBuffer     = String((rec.logBuffer + newLines.map(\.text).joined(separator: "\n")).suffix(2000))
            currentBuildRecord = rec
        }
        if msg.type == .status {
            isBuilding = false
            commitBuildRecord(outcome: msg.exitCode == 0 ? .success : .failure)
        }
    }

    // MARK: - History

    private func commitBuildRecord(outcome: BuildRecord.Outcome) {
        guard let rec = currentBuildRecord else { return }
        let duration = buildStartTime.map { Date().timeIntervalSince($0) } ?? 0
        historyStore.append(BuildRecord(
            id:            rec.id,
            projectName:   rec.projectName,
            scheme:        rec.scheme,
            date:          buildStartTime ?? Date(),
            duration:      duration,
            action:        rec.action,
            configuration: rec.configuration,
            destination:   rec.destination,
            outcome:       outcome,
            errorCount:    rec.errorCount,
            warningCount:  rec.warningCount,
            logSnippet:    String(rec.logBuffer.suffix(500))
        ))
        currentBuildRecord = nil
        buildStartTime     = nil
    }

    // MARK: - Reconnection

    private func onDaemonReconnected() async {
        appendConsole("🔌 Reconnected to daemon.", type: .info)
        await fetchDevices()
    }

    private func handleDaemonDisconnected() {
        guard isBuilding else { return }
        appendConsole("⚠️ Lost connection during build.", type: .error)
        isBuilding = false
        commitBuildRecord(outcome: .failure)
    }

    // MARK: - Console

    func appendConsole(_ text: String, type: ConsoleLine.LineType) {
        let lines = text.split(separator: "\n", omittingEmptySubsequences: false)
            .map { ConsoleLine(text: String($0), type: type) }
        consoleLines.append(contentsOf: lines)
    }

    func clearConsole() { consoleLines = [] }
}