import Foundation

/// The change a review thread's ```suggestion block proposes, as
/// `mr threads` carries it: lines `startLine` through `endLine` of `path`,
/// `original` replaced by `replacement`. Both texts end every line with
/// its terminator, so "" is no lines.
nonisolated struct Suggestion: Decodable, Sendable, Hashable {
    let path: String
    let startLine: Int64
    let endLine: Int64
    let original: String
    let replacement: String
    /// The lines it replaces have changed at the head, or the file moved;
    /// it cannot be applied then, and `reason` says which.
    let outdated: Bool
    let reason: String?
    /// "server" where `mr apply-suggestion` commits it; "local" where the
    /// repository requires signed commits, which only a clone can make.
    let apply: String

    enum CodingKeys: String, CodingKey {
        case path, original, replacement, outdated, reason, apply
        case startLine = "start_line"
        case endLine = "end_line"
    }

    var appliesOnServer: Bool { apply == "server" }

    /// The text as lines, without the terminator the last one carries.
    static func lines(_ text: String) -> [String] {
        guard !text.isEmpty else { return [] }
        var lines = text.components(separatedBy: "\n")
        if lines.last == "" { lines.removeLast() }
        return lines
    }

    /// A comment's text without its ```suggestion block, which the thread
    /// draws as replaced and proposed lines instead.
    static func withoutBlock(_ body: String) -> String {
        guard let start = body.range(of: "```suggestion") else { return body }
        let afterOpen = body[start.upperBound...]
        guard let close = afterOpen.range(of: "```") else { return body }
        let rest = body[..<start.lowerBound] + body[close.upperBound...]
        return rest.trimmingCharacters(in: .whitespacesAndNewlines)
    }
}