import Foundation

/// Editable view-model for one session's speaker corrections. Loads `speakers.json`
/// (+ optional `recap.json` and `cluster_fingerprints.json`), applies rename / merge
/// / per-segment reassignment, and on save rewrites `speakers.json`, re-renders
/// `transcript.md` + `recap.html`, and updates the voiceprint store (learning a voice
/// when an Unknown speaker is named).
@MainActor
final class RecapEditModel: ObservableObject {
    let folder: URL
    let title: String
    private let voiceprints: VoiceprintStore
    private let base: SpeakersFile
    private var recapFile: RecapFile?
    private let clusterFingerprints: [String: [Float]]
    private let originalSpeakers: [String]
    private var renameOps: [(from: String, to: String)] = []

    @Published private(set) var segments: [SpeakersFile.Segment]
    @Published private(set) var speakers: [String]
    @Published private(set) var dirty = false
    @Published private(set) var status: String?

    init?(folder: URL, voiceprints: VoiceprintStore) {
        let speakersURL = folder.appendingPathComponent("speakers.json")
        guard let data = try? Data(contentsOf: speakersURL),
              let file = try? JSONDecoder().decode(SpeakersFile.self, from: data),
              !file.segments.isEmpty else { return nil }
        self.folder = folder
        self.voiceprints = voiceprints
        self.base = file
        self.segments = file.segments
        self.speakers = SpeakerEditing.orderedSpeakers(file.segments)
        self.originalSpeakers = SpeakerEditing.orderedSpeakers(file.segments)
        self.recapFile = RecapFile.read(from: folder.appendingPathComponent("recap.json"))
        self.clusterFingerprints = Self.loadFingerprints(folder.appendingPathComponent("cluster_fingerprints.json"))
        self.title = recapFile?.title ?? file.app.capitalized + " call"
    }

    // MARK: - Edits

    func rename(_ name: String, to newName: String) {
        let to = newName.trimmingCharacters(in: .whitespacesAndNewlines)
        guard !to.isEmpty, to != name else { return }
        renameOps.append((from: name, to: to))
        segments = SpeakerEditing.replaceSpeaker(name, with: to, in: segments)
        refresh()
    }

    /// Merge is just a rename onto an existing speaker.
    func merge(_ absorbed: String, into survivor: String) {
        guard absorbed != survivor else { return }
        renameOps.append((from: absorbed, to: survivor))
        segments = SpeakerEditing.replaceSpeaker(absorbed, with: survivor, in: segments)
        refresh()
    }

    func reassign(_ index: Int, to speaker: String) {
        segments = SpeakerEditing.reassign(index, to: speaker, in: segments)
        refresh()
    }

    private func refresh() {
        speakers = SpeakerEditing.orderedSpeakers(segments)
        dirty = true
        status = nil
    }

    // MARK: - Save

    /// Persist corrections: rewrite speakers.json, re-render artifacts, update voiceprints.
    func save() {
        let newSpeakers = buildSpeakerList()
        let file = SpeakersFile(sessionId: base.sessionId, app: base.app, durationSec: base.durationSec,
                                speakers: newSpeakers, segments: segments, models: base.models)
        try? file.write(to: folder.appendingPathComponent("speakers.json"))

        let net = SpeakerEditing.netNameMap(originals: originalSpeakers, ops: renameOps)
        let result = recapFile.map { SpeakerEditing.remap($0.result, names: net) } ?? RecapResult(sections: [], extras: nil)
        if recapFile != nil {
            try? RecapFile(title: title, result: result).write(to: folder.appendingPathComponent("recap.json"))
        }
        try? RecapRenderer.write(file: file, result: result, title: title, to: folder)

        // Voiceprints: reconcile per the net rename/merge map.
        let stored = voiceprints.knownVoiceprints()
        for (orig, final) in net where !LabelMergeResponse.isUnknownName(final) {
            let finalHasPrint = clusterFingerprints[final] != nil || stored[final] != nil
            if finalHasPrint {
                // Merge into an existing identity → keep the survivor's print, drop the absorbed.
                if !LabelMergeResponse.isUnknownName(orig) { voiceprints.merge(orig, into: final) }
            } else if let vec = clusterFingerprints[orig] {
                // Rename / name an Unknown → learn this voice for the new name.
                voiceprints.enroll(name: final, vector: vec)
                if !LabelMergeResponse.isUnknownName(orig) { voiceprints.merge(orig, into: final) }
            } else {
                voiceprints.rename(orig, to: final)
            }
        }

        renameOps.removeAll()
        dirty = false
        status = "Saved — recap.html & transcript.md updated."
    }

    /// Speaker roster from the edited segments: keep the original source where the
    /// name is unchanged; mark new (renamed/merged) names as user-set.
    private func buildSpeakerList() -> [SpeakersFile.Speaker] {
        let byName = Dictionary(base.speakers.map { ($0.name, $0) }, uniquingKeysWith: { a, _ in a })
        return SpeakerEditing.orderedSpeakers(segments).map { name in
            byName[name] ?? SpeakersFile.Speaker(name: name, source: "manual", overlapConfidence: nil, matchSimilarity: nil)
        }
    }

    private static func loadFingerprints(_ url: URL) -> [String: [Float]] {
        guard let data = try? Data(contentsOf: url),
              let obj = try? JSONSerialization.jsonObject(with: data) as? [String: [Any]] else { return [:] }
        return obj.mapValues { $0.compactMap { ($0 as? NSNumber)?.floatValue } }
    }
}