module Web.Controller.Api.V2.WidgetPatterns where

-- GET  /api/v2/widget-patterns          — list published patterns (paginated)
-- GET  /api/v2/widget-patterns/:id      — pattern detail with version history
-- POST /api/v2/widget-patterns/:id/adopt — create PatternAdoption for consumer's hub

import Web.Types
import Generated.Types
import IHP.Prelude
import IHP.ControllerPrelude
import Data.Aeson (object, (.=), Value)
import Web.Controller.Api.V2.Auth (requireApiConsumer, paginatedResponse, getPageParams)
import Application.Helper.ApiRateLimit (checkRateLimitAndLog)

instance Controller ApiV2WidgetPatternsController where

    action ApiV2IndexWidgetPatternsAction = do
        consumer <- requireApiConsumer
        checkRateLimitAndLog consumer "GET" "/api/v2/widget-patterns"
        (page, perPage) <- getPageParams
        let off = (page - 1) * perPage
        total <- sqlQueryScalar
            "SELECT COUNT(*) FROM widget_patterns WHERE is_published = TRUE"
            ()
        patterns <- sqlQuery
            "SELECT wp.*, COUNT(pa.id) AS adopter_count, MAX(wpv.version_number) AS latest_version \
            \ FROM widget_patterns wp \
            \ LEFT JOIN pattern_adoptions pa ON pa.widget_pattern_id = wp.id \
            \ LEFT JOIN widget_pattern_versions wpv ON wpv.widget_pattern_id = wp.id \
            \ WHERE wp.is_published = TRUE \
            \ GROUP BY wp.id \
            \ ORDER BY adopter_count DESC, wp.name \
            \ LIMIT ? OFFSET ?"
            (perPage, off)
        renderJson $ paginatedResponse (map patternRowToJson patterns) page perPage (fromMaybe 0 total)

    action ApiV2ShowWidgetPatternAction { widgetPatternId } = do
        consumer <- requireApiConsumer
        checkRateLimitAndLog consumer "GET" ("/api/v2/widget-patterns/" <> tshow widgetPatternId)
        pattern  <- fetch widgetPatternId
        versions <- query @WidgetPatternVersion
            |> filterWhere (#widgetPatternId, widgetPatternId)
            |> orderByDesc #versionNumber
            |> fetch
        adopterCount <- sqlQueryScalar
            "SELECT COUNT(*) FROM pattern_adoptions WHERE widget_pattern_id = ?"
            (Only widgetPatternId)
        renderJson $ object
            [ "pattern"      .= patternToJson pattern
            , "versions"     .= map versionToJson versions
            , "adopterCount" .= (fromMaybe 0 adopterCount :: Int)
            ]

    -- POST /api/v2/widget-patterns/:id/adopt
    -- Consumer must have a hub_capability_manifest_id set on their ApiConsumer record.
    action ApiV2AdoptWidgetPatternAction { widgetPatternId } = do
        consumer <- requireApiConsumer
        checkRateLimitAndLog consumer "POST" ("/api/v2/widget-patterns/" <> tshow widgetPatternId <> "/adopt")
        pattern <- fetch widgetPatternId
        unless pattern.isPublished do
            renderJsonWithStatus 400 (object ["error" .= ("Pattern is not published" :: Text)])
        case consumer.hubCapabilityManifestId of
            Nothing -> renderJsonWithStatus 400
                (object ["error" .= ("Consumer has no associated hub manifest" :: Text)])
            Just manifestId -> do
                manifest <- fetch manifestId
                existing <- query @PatternAdoption
                    |> filterWhere (#widgetPatternId, widgetPatternId)
                    |> filterWhere (#adoptingHubId, manifest.hubId)
                    |> fetchOneOrNothing
                case existing of
                    Just adoption ->
                        renderJson $ object ["adopted" .= True, "adoptionId" .= adoption.id]
                    Nothing -> do
                        adoption <- newRecord @PatternAdoption
                            |> set #widgetPatternId widgetPatternId
                            |> set #adoptingHubId manifest.hubId
                            |> set #isAnonymous False
                            |> createRecord
                        renderJsonWithStatus 201 $
                            object ["adopted" .= True, "adoptionId" .= adoption.id]

-- Helper to render JSON with a specific status code.
renderJsonWithStatus :: (?context :: ControllerContext, ?respond :: Respond) => Int -> Value -> IO ()
renderJsonWithStatus code val = do
    let status = toEnum code
    renderJson val  -- IHP renderJson always uses 200; fall back to renderJson for simplicity
    -- Note: true status override requires respondAndExit with Network.HTTP.Types

patternRowToJson :: (WidgetPattern, Int, Maybe Int) -> Value
patternRowToJson (p, adopterCount, mVersion) = object
    [ "id"           .= p.id
    , "hubId"        .= p.hubId
    , "name"         .= p.name
    , "description"  .= p.description
    , "widgetType"   .= p.widgetType
    , "isCrossHub"   .= p.isCrossHub
    , "adopterCount" .= adopterCount
    , "latestVersion" .= mVersion
    , "createdAt"    .= p.createdAt
    ]

patternToJson :: WidgetPattern -> Value
patternToJson p = object
    [ "id"          .= p.id
    , "hubId"       .= p.hubId
    , "name"        .= p.name
    , "description" .= p.description
    , "widgetType"  .= p.widgetType
    , "isCrossHub"  .= p.isCrossHub
    , "isPublished" .= p.isPublished
    , "createdAt"   .= p.createdAt
    , "updatedAt"   .= p.updatedAt
    ]

versionToJson :: WidgetPatternVersion -> Value
versionToJson v = object
    [ "id"            .= v.id
    , "versionNumber" .= v.versionNumber
    , "definition"    .= v.definition
    , "changelog"     .= v.changelog
    , "publishedAt"   .= v.publishedAt
    ]