module Web.View.Hubs.GovernanceDashboard where

import Web.Types
import Generated.Types
import IHP.Prelude
import IHP.ViewPrelude
import Web.Routes ()

data GovernanceDashboardView = GovernanceDashboardView
    { hub                 :: !Hub
    , widgets             :: ![Widget]
    , allCandidates       :: ![RequirementCandidate]
    , allRequirements     :: ![Requirement]
    , recentDecisions     :: ![DecisionRecord]
    , allDecisions        :: ![DecisionRecord]
    , allAnnotations      :: ![Annotation]
    , regressionWidgetIds :: ![Id Widget]
    }

instance View GovernanceDashboardView where
    html GovernanceDashboardView { .. } = [hsx|
        <div class="mb-6 flex items-center justify-between">
            <div>
                <div class="flex items-center gap-2 text-sm text-gray-500 mb-1">
                    <a href={HubsAction} class="hover:text-gray-700">Hubs</a>
                    <span>/</span>
                    <a href={ShowHubAction (hub.id)} class="hover:text-gray-700">{hub.name}</a>
                    <span>/</span>
                    <span>Governance</span>
                </div>
                <h1 class="text-2xl font-semibold">Governance Dashboard — {hub.name}</h1>
            </div>
            <div class="flex gap-2">
                <a href={TriageDashboardAction (hub.id)}
                   class="text-sm border border-gray-300 px-3 py-1.5 rounded hover:bg-gray-50">
                    Triage Dashboard
                </a>
                <a href={AntifragilityDashboardAction (hub.id)}
                   class="text-sm border border-green-300 text-green-700 px-3 py-1.5 rounded hover:bg-green-50">
                    Antifragility
                </a>
                <a href={ShowHubAction (hub.id)}
                   class="text-sm border border-gray-300 px-3 py-1.5 rounded hover:bg-gray-50">
                    Hub Overview
                </a>
            </div>
        </div>

        <!-- KPI row: decision outcomes + regression -->
        <div class="grid grid-cols-3 gap-4 mb-4 sm:grid-cols-7">
            {forEach outcomeList (\o -> renderKpiCard o (countOutcome allDecisions o))}
            <div class="bg-red-50 text-red-800 rounded-lg px-4 py-3 text-center">
                <div class="text-2xl font-bold">{show (length regressionWidgetIds)}</div>
                <div class="text-xs mt-0.5 opacity-75">regressions</div>
            </div>
        </div>

        {if null regressionWidgetIds then mempty else renderGovRegressionAlerts regressedWidgets}

        <!-- Open requirements awaiting decision -->
        <div class="bg-white rounded-lg border border-gray-200 px-6 py-5 mb-6">
            <h2 class="text-sm font-semibold text-gray-700 mb-3">
                Open Requirements Awaiting Decision
                <span class="ml-2 text-xs font-normal text-gray-400">
                    ({show (length awaitingDecision)} pending)
                </span>
            </h2>
            {renderAwaitingSection awaitingDecision}
        </div>

        <!-- Recent decisions -->
        <div class="bg-white rounded-lg border border-gray-200 px-6 py-5 mb-6">
            <h2 class="text-sm font-semibold text-gray-700 mb-3">Recent Decisions</h2>
            {renderRecentDecisionsSection recentDecisions allRequirements allCandidates widgets}
        </div>

        <!-- Traceability coverage per widget -->
        <div class="bg-white rounded-lg border border-gray-200 px-6 py-5">
            <h2 class="text-sm font-semibold text-gray-700 mb-3">Traceability Coverage</h2>
            <table class="w-full text-sm">
                <thead class="border-b border-gray-100">
                    <tr>
                        <th class="text-left py-2 text-xs font-medium text-gray-500">Widget</th>
                        <th class="text-center py-2 text-xs font-medium text-gray-500">Annotation</th>
                        <th class="text-center py-2 text-xs font-medium text-gray-500">Candidate</th>
                        <th class="text-center py-2 text-xs font-medium text-gray-500">Decision</th>
                    </tr>
                </thead>
                <tbody class="divide-y divide-gray-50">
                    {forEach widgets (renderCoverageRow allAnnotations allCandidates allRequirements allDecisions)}
                </tbody>
            </table>
        </div>
    |]
  where
    awaitingDecision  = filter (isAwaitingDecision allDecisions) allRequirements
    regressedWidgets  = filter (\w -> w.id `elem` regressionWidgetIds) widgets

outcomeList :: [Text]
outcomeList = ["accepted", "rejected", "deferred", "split", "merged", "reframed"]

countOutcome :: [DecisionRecord] -> Text -> Int
countOutcome decisions o = length (filter (\d -> d.outcome == o) decisions)

renderKpiCard :: Text -> Int -> Html
renderKpiCard outcome count = [hsx|
    <div class={kpiCardClass outcome <> " rounded-lg px-4 py-3 text-center"}>
        <div class="text-2xl font-bold">{show count}</div>
        <div class="text-xs mt-0.5 opacity-75">{outcome}</div>
    </div>
|]

kpiCardClass :: Text -> Text
kpiCardClass "accepted"  = "bg-green-50 text-green-800"
kpiCardClass "rejected"  = "bg-red-50 text-red-800"
kpiCardClass "deferred"  = "bg-gray-50 text-gray-700"
kpiCardClass "split"     = "bg-purple-50 text-purple-800"
kpiCardClass "merged"    = "bg-indigo-50 text-indigo-800"
kpiCardClass "reframed"  = "bg-orange-50 text-orange-800"
kpiCardClass _           = "bg-gray-50 text-gray-700"

isAwaitingDecision :: [DecisionRecord] -> Requirement -> Bool
isAwaitingDecision decisions req =
    not (any (\d -> d.requirementId == Just req.id) decisions)

renderAwaitingReq :: Requirement -> Html
renderAwaitingReq req = [hsx|
    <div class="flex items-center justify-between py-2 border-b border-gray-50 last:border-0">
        <a href={ShowRequirementAction (req.id)}
           class="text-sm text-indigo-600 hover:text-indigo-800">{req.title}</a>
        <span class="text-xs text-gray-400">{show req.createdAt}</span>
    </div>
|]

renderDecisionRow :: [Requirement] -> [RequirementCandidate] -> [Widget] -> DecisionRecord -> Html
renderDecisionRow reqs candidates widgets dr = [hsx|
    <tr>
        <td class="py-2 pr-4">
            <a href={ShowDecisionRecordAction (dr.id)}
               class="text-indigo-600 hover:text-indigo-800">{dr.title}</a>
        </td>
        <td class="py-2 pr-4">
            <span class={outcomeClass dr.outcome <> " text-xs px-2 py-0.5 rounded font-medium"}>
                {dr.outcome}
            </span>
        </td>
        <td class="py-2 pr-4 text-gray-600 text-xs">
            {originWidget dr reqs candidates widgets}
        </td>
        <td class="py-2 text-gray-400 text-xs">{show dr.decidedAt}</td>
    </tr>
|]

-- Trace decision → requirement → candidate → widget name
originWidget :: DecisionRecord -> [Requirement] -> [RequirementCandidate] -> [Widget] -> Text
originWidget dr reqs candidates widgets =
    case dr.requirementId >>= \rid -> find (\r -> r.id == rid) reqs of
        Just req ->
            case find (\c -> c.id == req.sourceCandidateId) candidates of
                Just c ->
                    case find (\w -> w.id == c.sourceWidgetId) widgets of
                        Just w  -> w.name
                        Nothing -> "—"
                Nothing -> "—"
        Nothing ->
            case dr.candidateId >>= \cid -> find (\c -> c.id == cid) candidates of
                Just c ->
                    case find (\w -> w.id == c.sourceWidgetId) widgets of
                        Just w  -> w.name
                        Nothing -> "—"
                Nothing -> "—"

renderCoverageRow :: [Annotation] -> [RequirementCandidate] -> [Requirement] -> [DecisionRecord] -> Widget -> Html
renderCoverageRow annotations candidates requirements decisions w = [hsx|
    <tr>
        <td class="py-2 pr-4 text-sm text-gray-700">{w.name}</td>
        <td class="py-2 text-center">{coverageMark hasAnnotation}</td>
        <td class="py-2 text-center">{coverageMark hasCandidate}</td>
        <td class="py-2 text-center">{coverageMark hasDecision}</td>
    </tr>
|]
  where
    hasAnnotation = any (\a -> a.widgetId == w.id) annotations
    widgetCandidates = filter (\c -> c.sourceWidgetId == w.id) candidates
    hasCandidate = not (null widgetCandidates)
    candidateIds = map (.id) widgetCandidates
    widgetReqIds = map (.id) (filter (\r -> r.sourceCandidateId `elem` candidateIds) requirements)
    hasDecision  = any (\d -> d.requirementId `elem` map Just widgetReqIds) decisions

renderRegressedBadge :: Widget -> Html
renderRegressedBadge w = [hsx|
    <a href={ShowWidgetAction (w.id)}
       class="text-xs bg-red-100 text-red-800 border border-red-300 rounded px-2 py-1 hover:bg-red-200">
        {w.name}
    </a>
|]

coverageMark :: Bool -> Html
coverageMark True  = [hsx|<span class="text-green-600 font-bold">✓</span>|]
coverageMark False = [hsx|<span class="text-gray-300">✗</span>|]

renderGovRegressionAlerts :: [Widget] -> Html
renderGovRegressionAlerts ws = [hsx|
    <div class="bg-red-50 border border-red-200 rounded-lg px-6 py-4 mb-6">
        <h2 class="text-sm font-semibold text-red-700 mb-3">Regression Alerts</h2>
        <div class="flex flex-wrap gap-2">
            {forEach ws renderRegressedBadge}
        </div>
    </div>
|]

renderAwaitingSection :: [Requirement] -> Html
renderAwaitingSection [] = [hsx|<p class="text-sm text-gray-400">All requirements have linked decisions.</p>|]
renderAwaitingSection reqs = [hsx|{forEach reqs renderAwaitingReq}|]

renderRecentDecisionsSection :: [DecisionRecord] -> [Requirement] -> [RequirementCandidate] -> [Widget] -> Html
renderRecentDecisionsSection [] _ _ _ = [hsx|<p class="text-sm text-gray-400">No decisions recorded yet.</p>|]
renderRecentDecisionsSection decisions reqs candidates ws = [hsx|
    <table class="w-full text-sm">
        <thead class="border-b border-gray-100">
            <tr>
                <th class="text-left py-2 text-xs font-medium text-gray-500">Title</th>
                <th class="text-left py-2 text-xs font-medium text-gray-500">Outcome</th>
                <th class="text-left py-2 text-xs font-medium text-gray-500">Source Widget</th>
                <th class="text-left py-2 text-xs font-medium text-gray-500">Decided At</th>
            </tr>
        </thead>
        <tbody class="divide-y divide-gray-50">
            {forEach decisions (renderDecisionRow reqs candidates ws)}
        </tbody>
    </table>
|]

outcomeClass :: Text -> Text
outcomeClass "accepted"  = "bg-green-100 text-green-800"
outcomeClass "rejected"  = "bg-red-100 text-red-800"
outcomeClass "deferred"  = "bg-gray-100 text-gray-600"
outcomeClass "split"     = "bg-purple-100 text-purple-800"
outcomeClass "merged"    = "bg-indigo-100 text-indigo-800"
outcomeClass "reframed"  = "bg-orange-100 text-orange-800"
outcomeClass _           = "bg-gray-100 text-gray-600"