# Sync project templates to target project.
# - Copies templates/memory-bank/ -> <project-root>/memory-bank/
# - Copies templates/prompts/ -> <project-root>/docs/prompts/
# - Copies templates/AGENTS.template.md -> <project-root>/AGENTS.md
# - Copies templates/AGENT_RULES.template.md -> <project-root>/AGENT_RULES.md
# Existing targets are backed up before overwrite.
[CmdletBinding()]
param(
  [Parameter(Mandatory = $false)]
  [Alias('h', '?')]
  [switch]$Help,

  [Parameter(Mandatory = $false)]
  [string]$ProjectRoot,

  [Parameter(Mandatory = $false)]
  [string]$ProjectName,

  [Parameter(Mandatory = $false)]
  [string]$Date,

  [Parameter(Mandatory = $false)]
  [switch]$NoBackup,

  [Parameter(Mandatory = $false)]
  [switch]$Force,

  [Parameter(Mandatory = $false)]
  [switch]$Full
)

$ErrorActionPreference = "Stop"

if ($Help) {
  Write-Host "Usage:"
  Write-Host "  powershell -File scripts/sync_templates.ps1 [options]"
  Write-Host "  powershell -File scripts/sync_templates.ps1 -ProjectRoot C:\\path\\to\\project"
  Write-Host ""
  Write-Host "Options:"
  Write-Host "  -ProjectRoot PATH  Target project root (default: git root)."
  Write-Host "  -ProjectName NAME   Replace {{PROJECT_NAME}} placeholder."
  Write-Host "  -Date DATE          Replace {{DATE}} placeholder (default: today)."
  Write-Host "  -NoBackup           Skip backup of existing files."
  Write-Host "  -Force              Overwrite without prompting."
  Write-Host "  -Full               Append full framework section to AGENTS.md."
  Write-Host "  -Help               Show this help."
  exit 0
}
$ScriptDir = Split-Path -Parent $MyInvocation.MyCommand.Path
$Src = (Resolve-Path (Join-Path $ScriptDir "..")).Path

# Defaults
if (-not $Date) {
  $Date = Get-Date -Format "yyyy-MM-dd"
}

# Determine project root
if (-not $ProjectRoot) {
  $ProjectRoot = (git -C $ScriptDir rev-parse --show-toplevel 2>$null)
  if (-not $ProjectRoot) { $ProjectRoot = (Get-Location).Path }
}
$ProjectRoot = (Resolve-Path $ProjectRoot).Path

# Source directories
$TemplatesDir = Join-Path $Src "templates"
$MemoryBankSrc = Join-Path $TemplatesDir "memory-bank"
$PromptsSrc = Join-Path $TemplatesDir "prompts"
$AgentsSrc = Join-Path $TemplatesDir "AGENTS.template.md"
$AgentRulesSrc = Join-Path $TemplatesDir "AGENT_RULES.template.md"

# Check source exists
if (-not (Test-Path $TemplatesDir)) {
  throw "Templates directory not found: $TemplatesDir"
}

# Skip if source equals destination
if ($Src -ieq $ProjectRoot) {
  Write-Host "Skip: playbook root equals project root."
  Write-Host "Done."
  exit 0
}

$timestamp = Get-Date -Format "yyyyMMddHHmmss"

# Function: backup file/directory
function Backup-IfExists {
  param([string]$Target)

  if ((Test-Path $Target) -and -not $NoBackup) {
    $backup = "$Target.bak.$timestamp"
    Move-Item $Target $backup
    Write-Host "Backed up: $(Split-Path -Leaf $Target) -> $(Split-Path -Leaf $backup)"
  }
}

# Function: replace placeholders in file
function Replace-Placeholders {
  param([string]$File)

  if (-not (Test-Path $File)) { return }

  $content = Get-Content -Raw -Path $File
  if ($ProjectName) {
    $content = $content.Replace("{{PROJECT_NAME}}", $ProjectName)
  }
  $content = $content.Replace("{{DATE}}", $Date)
  Set-Content -Path $File -Value $content -Encoding UTF8 -NoNewline
}

# Function: replace placeholders in directory
function Replace-PlaceholdersDir {
  param([string]$Dir)

  if (-not (Test-Path $Dir)) { return }

  Get-ChildItem -Path $Dir -Filter "*.md" -Recurse -File | ForEach-Object {
    Replace-Placeholders -File $_.FullName
  }
}

Write-Host "Syncing templates to: $ProjectRoot"
Write-Host ""

# 1. Sync memory-bank/
if (Test-Path $MemoryBankSrc) {
  $MemoryBankDst = Join-Path $ProjectRoot "memory-bank"

  if ((Test-Path $MemoryBankDst) -and -not $Force) {
    Write-Host "memory-bank/ already exists. Use -Force to overwrite."
  } else {
    Backup-IfExists -Target $MemoryBankDst
    New-Item -ItemType Directory -Path $MemoryBankDst -Force | Out-Null
    Copy-Item -Path (Join-Path $MemoryBankSrc "*") -Destination $MemoryBankDst -Recurse -Force

    # Rename .template.md to .md
    Get-ChildItem -Path $MemoryBankDst -Filter "*.template.md" -File | ForEach-Object {
      $newName = $_.Name -replace "\.template\.md$", ".md"
      Rename-Item -Path $_.FullName -NewName $newName
    }

    Replace-PlaceholdersDir -Dir $MemoryBankDst
    Write-Host "Synced: memory-bank/"
  }
} else {
  Write-Host "Skip: memory-bank/ templates not found"
}

# 2. Sync docs/prompts/
if (Test-Path $PromptsSrc) {
  $PromptsDst = Join-Path $ProjectRoot "docs\prompts"

  if ((Test-Path $PromptsDst) -and -not $Force) {
    Write-Host "docs/prompts/ already exists. Use -Force to overwrite."
  } else {
    Backup-IfExists -Target $PromptsDst
    $DocsDir = Join-Path $ProjectRoot "docs"
    New-Item -ItemType Directory -Path $DocsDir -Force | Out-Null
    New-Item -ItemType Directory -Path $PromptsDst -Force | Out-Null
    Copy-Item -Path (Join-Path $PromptsSrc "*") -Destination $PromptsDst -Recurse -Force

    # Rename .template.md to .md recursively
    Get-ChildItem -Path $PromptsDst -Filter "*.template.md" -Recurse -File | ForEach-Object {
      $newName = $_.Name -replace "\.template\.md$", ".md"
      Rename-Item -Path $_.FullName -NewName $newName
    }

    Replace-PlaceholdersDir -Dir $PromptsDst
    Write-Host "Synced: docs/prompts/"
  }
} else {
  Write-Host "Skip: prompts/ templates not found"
}

# 3. Sync AGENTS.md
# Choose markers based on -Full flag
if ($Full) {
  $MarkerStart = "<!-- playbook:framework:start -->"
  $MarkerEnd = "<!-- playbook:framework:end -->"
  $SectionName = "framework"
} else {
  $MarkerStart = "<!-- playbook:templates:start -->"
  $MarkerEnd = "<!-- playbook:templates:end -->"
  $SectionName = "templates"
}

if (Test-Path $AgentsSrc) {
  $AgentsDst = Join-Path $ProjectRoot "AGENTS.md"

  if (-not (Test-Path $AgentsDst)) {
    # AGENTS.md doesn't exist: create from full template
    Copy-Item -Path $AgentsSrc -Destination $AgentsDst -Force
    Replace-Placeholders -File $AgentsDst
    Write-Host "Created: AGENTS.md"
  } else {
    # AGENTS.md exists: update or append section
    # Extract snippet from template
    $templateContent = Get-Content -Raw -Path $AgentsSrc
    $extractPattern = "(?s)(" + [regex]::Escape($MarkerStart) + ".*?" + [regex]::Escape($MarkerEnd) + ")"
    if ($templateContent -match $extractPattern) {
      $snippetContent = $Matches[1]

      $content = Get-Content -Raw -Path $AgentsDst

      if ($content -match [regex]::Escape($MarkerStart)) {
        # Has markers: replace content between markers
        $replacePattern = "(?s)" + [regex]::Escape($MarkerStart) + ".*?" + [regex]::Escape($MarkerEnd)
        $newContent = $content -replace $replacePattern, $snippetContent
        Set-Content -Path $AgentsDst -Value $newContent -Encoding UTF8 -NoNewline
        Replace-Placeholders -File $AgentsDst
        Write-Host "Updated: AGENTS.md ($SectionName section)"
      } else {
        # No markers: append snippet at the end
        $newContent = $content.TrimEnd() + "`n`n" + $snippetContent
        Set-Content -Path $AgentsDst -Value $newContent -Encoding UTF8 -NoNewline
        Replace-Placeholders -File $AgentsDst
        Write-Host "Appended: AGENTS.md ($SectionName section)"
      }
    } else {
      Write-Host "Skip: markers not found in template"
    }
  }
} else {
  Write-Host "Skip: AGENTS.template.md not found"
}

# 4. Sync AGENT_RULES.md
if (Test-Path $AgentRulesSrc) {
  $AgentRulesDst = Join-Path $ProjectRoot "AGENT_RULES.md"

  if ((Test-Path $AgentRulesDst) -and -not $Force) {
    Write-Host "AGENT_RULES.md already exists. Use -Force to overwrite."
  } else {
    Backup-IfExists -Target $AgentRulesDst
    Copy-Item -Path $AgentRulesSrc -Destination $AgentRulesDst -Force
    Replace-Placeholders -File $AgentRulesDst
    Write-Host "Synced: AGENT_RULES.md"
  }
} else {
  Write-Host "Skip: AGENT_RULES.template.md not found"
}

Write-Host ""
Write-Host "Done."
Write-Host ""
Write-Host "Next steps:"
Write-Host "  1. Edit memory-bank/*.md to fill in project-specific content"
Write-Host "  2. Replace remaining {{PLACEHOLDER}} values"
Write-Host "  3. Run sync_standards.ps1 to sync .agents/ rules"