-- Resolve the game's patch notes for the launcher footer modal.
--
-- Sources, first hit wins:
--   1. The GitHub body the self-updater already fetched (Check.parseRelease)
--   2. PATCH_NOTES.md, if a build packed one
--   3. mobile/ios/app-repo.json -- CI copies each release's notes into
--      versions[].localizedDescription, so a checkout already has them
--      on disk even when the updater has not run

local Json = require("src.link.Json")

local PatchNotes = {}

PatchNotes.FILES = {
  "PATCH_NOTES.md",
  "assets/PATCH_NOTES.md",
}

PatchNotes.REPO_FILES = {
  "mobile/ios/app-repo.json",
}

local function nonempty(s)
  return type(s) == "string" and s:find("%S")
end

function PatchNotes.fromCheck(Check)
  if not (Check and Check.state) then return nil, nil end
  local ok, st = pcall(Check.state)
  st = (ok and type(st) == "table") and st or nil
  if not st then return nil, nil end
  if nonempty(st.notes) then
    return st.notes, st.latest
  end
  return nil, st.latest
end

local function readPath(path)
  local fs = love and love.filesystem
  if fs and fs.read then
    local ok, text = pcall(fs.read, path)
    if ok and nonempty(text) then return text end
  end
  local f = io.open(path, "rb")
  if not f then return nil end
  local text = f:read("*a")
  f:close()
  return nonempty(text) and text or nil
end

function PatchNotes.fromFile()
  for _, path in ipairs(PatchNotes.FILES) do
    local text = readPath(path)
    if text then return text end
  end
  return nil
end

-- Newest-first list of { version, notes } from the iOS sidecar.
function PatchNotes.parseRepo(jsonText)
  local doc = Json.decode(jsonText)
  if type(doc) ~= "table" or type(doc.apps) ~= "table" then return {} end
  local out = {}
  for _, app in ipairs(doc.apps) do
    if type(app) == "table" and type(app.versions) == "table" then
      for _, row in ipairs(app.versions) do
        if type(row) == "table" and nonempty(row.localizedDescription) then
          out[#out + 1] = {
            version = row.version,
            notes = row.localizedDescription,
          }
        end
      end
    end
  end
  return out
end

function PatchNotes.fromRepo(engine)
  for _, path in ipairs(PatchNotes.REPO_FILES) do
    local text = readPath(path)
    if text then
      local list = PatchNotes.parseRepo(text)
      if #list == 0 then return nil, nil end
      if engine and engine ~= "0.0.0-dev" then
        for _, row in ipairs(list) do
          if row.version == engine then
            return row.notes, row.version
          end
        end
      end
      return list[1].notes, list[1].version
    end
  end
  return nil, nil
end

function PatchNotes.body(Check)
  local notes, ver = PatchNotes.fromCheck(Check)
  if notes then return notes, ver end
  notes = PatchNotes.fromFile()
  if notes then return notes, ver end
  local Version = require("src.core.Version")
  local engine = (Version and Version.engine) or "?"
  notes, ver = PatchNotes.fromRepo(engine)
  if notes then return notes, ver end
  return "No patch notes loaded yet for gen1recomp v" .. engine .. ".\n\n"
    .. "They appear here after the launcher checks GitHub for the latest "
    .. "release.", engine
end

return PatchNotes