<#
.SYNOPSIS
    Renders the JSON output of Suggest-ArticleSignals.ps1 into a single,
    non-blocking Markdown PR advisory comment with embedded feedback metadata.

.DESCRIPTION
    The automated authoring-assist advisory posts ONE consolidated comment per
    PR (update-in-place) built from the per-article suggestions. Each article
    section carries HTML metadata markers so downstream feedback tooling (the
    BC-ALAgentsInternal harvester) can correlate reactions and applied/not-applied
    outcomes back to a specific suggestion via its stable `suggestionId`.

    The comment is ADVISORY ONLY: it never fails a build, it only suggests
    front-matter an author eyeballs and applies via a normal PR. R29
    (validate_frontmatter.py), CI, and CODEOWNERS remain the gate.

    Markers emitted (stable contract — do not change without bumping the tool
    schema and updating the harvester):

        <!-- authoring-assist-advisory -->                 top anchor (find/update)
        <!-- aa:meta schema="X" tool="Y" generated="Z" articles="N" -->
        <!-- aa:article path="..." domain="..." effect="raise|suppress"
                        suppressor="true|false" suggestions="id1,id2,..." -->

.PARAMETER JsonPath
    Path to a file containing the `Suggest-ArticleSignals.ps1 -AsJson` output.
    If omitted, JSON is read from stdin.

.PARAMETER RepoUrl
    Base repo URL used to build article permalinks (e.g.
    https://github.com/microsoft/BCQuality). Optional; when omitted, article
    paths are rendered as inline code without links.

.PARAMETER Ref
    Git ref/SHA the suggestions were computed against, used in permalinks and
    surfaced in the footer for provenance. Optional.

.PARAMETER DocUrl
    URL surfaced in the feedback footer ("reply with why"). Optional.

.OUTPUTS
    Writes the Markdown comment body to stdout.
#>
[CmdletBinding()]
param(
    [string] $JsonPath,
    [string] $RepoUrl,
    [string] $Ref,
    [string] $DocUrl
)

Set-StrictMode -Version Latest
$ErrorActionPreference = 'Stop'

$Anchor = '<!-- authoring-assist-advisory -->'

if ($JsonPath) {
    if (-not (Test-Path -LiteralPath $JsonPath)) { throw "JSON file not found: $JsonPath" }
    $raw = Get-Content -LiteralPath $JsonPath -Raw
} else {
    $raw = [Console]::In.ReadToEnd()
}
if ([string]::IsNullOrWhiteSpace($raw)) { throw 'No JSON input provided (empty file/stdin).' }

$data = $raw | ConvertFrom-Json

$reports = @()
if ($data.PSObject.Properties.Name -contains 'reports' -and $data.reports) {
    $reports = @($data.reports)
}

function Format-Provenance {
    param([object] $Proposal)
    $tags = [System.Collections.Generic.List[string]]::new()
    if ($Proposal.keywordBacked) { $tags.Add('keyword-backed') | Out-Null }
    if ($Proposal.inBad)         { $tags.Add('anti-pattern sample') | Out-Null }
    if ($Proposal.proseOnly)     { $tags.Add('prose-only') | Out-Null }
    if ($tags.Count -eq 0)       { $tags.Add('sample') | Out-Null }
    return ($tags -join ', ')
}

function Format-SignalsBlock {
    param([object] $Report)
    $lines = [System.Collections.Generic.List[string]]::new()
    $lines.Add('signals:') | Out-Null
    foreach ($p in $Report.proposals) {
        if ($Report.effect -eq 'suppress') {
            $lines.Add("  - token: $($p.token)") | Out-Null
            $lines.Add('    effect: suppress') | Out-Null
        } else {
            $lines.Add("  - $($p.token)") | Out-Null
        }
    }
    return ($lines -join "`n")
}

$body = [System.Collections.Generic.List[string]]::new()
$body.Add($Anchor) | Out-Null

$schema    = if ($data.PSObject.Properties.Name -contains 'schemaVersion') { $data.schemaVersion } else { 'unknown' }
$toolVer   = if ($data.PSObject.Properties.Name -contains 'toolVersion')   { $data.toolVersion }   else { 'unknown' }
$generated = if ($data.PSObject.Properties.Name -contains 'generatedAt')   { $data.generatedAt }   else { '' }

$body.Add(('<!-- aa:meta schema="{0}" tool="{1}" generated="{2}" articles="{3}" -->' -f $schema, $toolVer, $generated, @($reports).Count)) | Out-Null
$body.Add('') | Out-Null
$body.Add('## 🧭 Authoring-assist advisory') | Out-Null
$body.Add('') | Out-Null

if (@($reports).Count -eq 0) {
    $body.Add('No routing head-matter suggestions for the knowledge articles changed in this PR. ✅') | Out-Null
    $body.Add('') | Out-Null
    $body.Add('<sub>Advisory only — never blocks a merge. Generated by `tools/Suggest-ArticleSignals.ps1`.</sub>') | Out-Null
    return ($body -join "`n")
}

$body.Add(("This PR changes knowledge articles whose routing head-matter could be improved. " +
           "These are **non-blocking suggestions** — paste the proposed ``signals:`` block into the " +
           "article's front-matter if it looks right. R29 + CODEOWNERS still review the change.")) | Out-Null
$body.Add('') | Out-Null

foreach ($r in ($reports | Sort-Object domain, path)) {
    $effect = $r.effect
    $badge  = if ($r.suppressor) { '🛡️ suppressor' } else { '🎯 trigger' }

    $suggestionIds = @($r.proposals | ForEach-Object { $_.suggestionId }) -join ','
    $body.Add(('<!-- aa:article path="{0}" domain="{1}" effect="{2}" suppressor="{3}" suggestions="{4}" -->' -f `
                $r.path, $r.domain, $effect, ([string]$r.suppressor).ToLowerInvariant(), $suggestionIds)) | Out-Null

    $title = if ($RepoUrl -and $Ref) { "[``$($r.path)``]($RepoUrl/blob/$Ref/$($r.path))" } else { "``$($r.path)``" }
    $body.Add("### $title") | Out-Null
    $body.Add("**Domain:** ``$($r.domain)`` &nbsp;·&nbsp; $badge &nbsp;·&nbsp; ``effect: $effect``") | Out-Null
    $body.Add('') | Out-Null

    if (@($r.proposals).Count -gt 0) {
        $body.Add('Proposed front-matter:') | Out-Null
        $body.Add('') | Out-Null
        $body.Add('```yaml') | Out-Null
        $body.Add((Format-SignalsBlock -Report $r)) | Out-Null
        $body.Add('```') | Out-Null
        $body.Add('') | Out-Null
        foreach ($p in $r.proposals) {
            $body.Add(("- ``$($p.token)`` — {0} · {1}" -f (Format-Provenance -Proposal $p), $p.note)) | Out-Null
        }
        $body.Add('') | Out-Null
    }

    if ($r.mismatch) {
        $body.Add("> ⚠️ **Domain check:** $($r.mismatch)") | Out-Null
        $body.Add('') | Out-Null
    }
    if ($r.applicability) {
        $body.Add("> ⚠️ **Applicability:** $($r.applicability)") | Out-Null
        $body.Add('') | Out-Null
    }
    if (@($r.keywordSuggestions).Count -gt 0) {
        $kw = @($r.keywordSuggestions | ForEach-Object { '`' + $_ + '`' }) -join ', '
        $body.Add("> 💡 **Keywords:** consider adding $kw") | Out-Null
        $body.Add('') | Out-Null
    }
}

$replyLink = if ($DocUrl) { " - <a href=`"$DocUrl`">reply with why</a>" } else { '' }
$provenance = if ($Ref) { " against ``$Ref``" } else { '' }
$body.Add('---') | Out-Null
$body.Add("<sub>👍 useful · ❤️ especially valuable · 👎 wrong$replyLink</sub>") | Out-Null
$body.Add("<sub>Advisory only — never blocks a merge. Generated by ``tools/Suggest-ArticleSignals.ps1``$provenance. Suggestions carry stable ids for feedback; applying them is optional and human-reviewed.</sub>") | Out-Null

return ($body -join "`n")