import Foundation

/// Emoji reactions on a post in a thread.
public struct OrgSocialMood: Sendable, Equatable {
    public let emoji: String
    public let posts: [String]

    public init(emoji: String, posts: [String]) {
        self.emoji = emoji
        self.posts = posts
    }
}

/// A node in the reply tree: a fully-resolved post plus its nested children.
public struct OrgSocialThreadNode: Sendable {
    public let post: OrgSocialPost
    public let children: [OrgSocialThreadNode]
    public let moods: [OrgSocialMood]

    public init(post: OrgSocialPost, children: [OrgSocialThreadNode] = [], moods: [OrgSocialMood] = []) {
        self.post = post
        self.children = children
        self.moods = moods
    }
}

/// A fully-resolved conversation thread.
public struct OrgSocialThread: Sendable {
    /// The post the thread was opened from.
    public let focalPost: OrgSocialPost
    /// Ancestor posts, oldest first (may be empty).
    public let parentChain: [OrgSocialPost]
    /// Direct replies to the focal post, each with their own nested children.
    public let replies: [OrgSocialThreadNode]
    /// Emoji reactions on the focal post.
    public let moods: [OrgSocialMood]

    public init(
        focalPost: OrgSocialPost,
        parentChain: [OrgSocialPost] = [],
        replies: [OrgSocialThreadNode] = [],
        moods: [OrgSocialMood] = []
    ) {
        self.focalPost = focalPost
        self.parentChain = parentChain
        self.replies = replies
        self.moods = moods
    }

    /// Total number of replies (all depths combined).
    public var replyCount: Int {
        replies.reduce(0) { $0 + 1 + countChildren($1) }
    }

    private func countChildren(_ node: OrgSocialThreadNode) -> Int {
        node.children.reduce(0) { $0 + 1 + countChildren($1) }
    }
}

/// Interaction summary for a post (from /interactions/).
public struct OrgSocialInteractions: Sendable {
    public let replyCount: Int
    public let reactionCount: Int
    public let boostCount: Int
    public let replyURLs: [String]
    /// Post URLs of the boost posts (one per booster). The feed URL of each
    /// booster is the prefix before `#` — useful for cross-checking "did I
    /// boost this?" without refetching the user's own feed.
    public let boostURLs: [String]
    /// Emoji reactions grouped by emoji, sorted by count descending.
    public let reactions: [OrgSocialMood]

    public init(
        replyCount: Int,
        reactionCount: Int,
        boostCount: Int,
        replyURLs: [String],
        boostURLs: [String] = [],
        reactions: [OrgSocialMood] = []
    ) {
        self.replyCount = replyCount
        self.reactionCount = reactionCount
        self.boostCount = boostCount
        self.replyURLs = replyURLs
        self.boostURLs = boostURLs
        self.reactions = reactions
    }

    public var hasActivity: Bool { replyCount > 0 || reactionCount > 0 || boostCount > 0 }
}