package api

import (
	"fmt"
	"html"
	"net/http"
	"strings"

	"provisioning/internal/model"
)

func renderHTML(w http.ResponseWriter, body string) {
	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	w.Write([]byte(body))
}

func dashboardPage(hosts []model.Host) string {
	var tiles strings.Builder
	for _, h := range hosts {
		tiles.WriteString(hostTile(h))
	}
	if len(hosts) == 0 {
		tiles.WriteString(`<p class="empty">No hosts registered. <a href="/hosts/new">Register one.</a></p>`)
	}
	return layout("Dashboard", fmt.Sprintf(`
		<div class="actions">
			<a href="/hosts/new" class="btn">Register Host</a>
			<span class="count">%d hosts</span>
		</div>
		<div class="host-grid">%s</div>
	`, len(hosts), tiles.String()))
}

func hostTile(h model.Host) string {
	stateClass := stateColor(h.State)
	led := ledClass(h.State)
	return fmt.Sprintf(`
		<a href="/hosts/%d" class="tile %s" id="tile-%d">
			<div class="tile-header">
				<span class="led led-lg %s"></span>
				<span class="tile-name">%s</span>
			</div>
			<div class="tile-meta">
				<span class="tile-type">%s</span>
			</div>
			<div class="tile-footer">
				<span class="tile-mac">%s</span>
				<span class="tile-state-label">%s</span>
			</div>
		</a>
	`, h.ID, stateClass, h.ID, led, html.EscapeString(h.Hostname), html.EscapeString(h.ServerType), h.MAC, h.State)
}

func hostFormPage(types []string, errMsg string, prefill *model.Host) string {
	var opts strings.Builder
	for _, t := range types {
		selected := ""
		if prefill != nil && prefill.ServerType == t {
			selected = " selected"
		}
		opts.WriteString(fmt.Sprintf(`<option value="%s"%s>%s</option>`, t, selected, t))
	}
	errHTML := ""
	if errMsg != "" {
		errHTML = fmt.Sprintf(`<div class="error">%s</div>`, html.EscapeString(errMsg))
	}
	hostname, mac, notes := "", "", ""
	if prefill != nil {
		hostname = html.EscapeString(prefill.Hostname)
		mac = html.EscapeString(prefill.MAC)
		notes = html.EscapeString(prefill.Notes)
	}
	return layout("Register Host", fmt.Sprintf(`
		<h2>Register Host</h2>
		%s
		<form method="POST" action="/hosts" class="form">
			<label>Hostname<input type="text" name="hostname" value="%s" required></label>
			<label>MAC Address<input type="text" name="mac" value="%s" placeholder="aa:bb:cc:dd:ee:ff" required></label>
			<label>Server Type<select name="server_type" required>%s</select></label>
			<label>Notes<textarea name="notes">%s</textarea></label>
			<button type="submit" class="btn">Register</button>
		</form>
	`, errHTML, hostname, mac, opts.String(), notes))
}

func hostDetailPage(h *model.Host, ops []model.Operation) string {
	stateClass := stateColor(h.State)
	led := ledClass(h.State)
	canRebuild := h.State == model.StateRegistered || h.State == model.StateReady || h.State == model.StateFailed

	var actions strings.Builder
	if canRebuild {
		actions.WriteString(fmt.Sprintf(`<form method="POST" action="/hosts/%d/rebuild" class="inline"><button class="btn">Rebuild</button></form>`, h.ID))
	}
	actions.WriteString(fmt.Sprintf(`<form method="POST" action="/hosts/%d/delete" class="inline" onsubmit="return confirm('Delete this host?')"><button class="btn btn-danger">Delete</button></form>`, h.ID))

	var opsHTML strings.Builder
	for _, op := range ops {
		duration := ""
		if op.CompletedAt != nil {
			duration = op.CompletedAt.Sub(op.StartedAt).Truncate(1e9).String()
		}
		errCell := ""
		if op.ErrorMessage != "" {
			errCell = html.EscapeString(op.ErrorMessage)
		}
		opsHTML.WriteString(fmt.Sprintf(`<tr><td>%s</td><td>%s</td><td>%s</td><td>%s</td><td>%s</td></tr>`,
			op.Kind, op.State, op.StartedAt.Format("2006-01-02 15:04"), duration, errCell))
	}

	ip := h.IPAddress
	if ip == "" {
		ip = "—"
	}

	return layout(h.Hostname, fmt.Sprintf(`
		<div class="host-header">
			<span class="led led-lg %s"></span>
			<h2 style="margin-bottom:0">%s</h2>
			<span class="badge %s">%s</span>
		</div>
		<div class="panel">
			<table class="detail-table">
				<tr><th>MAC</th><td>%s</td></tr>
				<tr><th>Server Type</th><td>%s</td></tr>
				<tr><th>IP Address</th><td>%s</td></tr>
				<tr><th>Notes</th><td>%s</td></tr>
			</table>
			<div class="actions">%s</div>
		</div>
		<h3>Operations</h3>
		<div class="panel">
			<table class="ops-table">
				<thead><tr><th>Kind</th><th>State</th><th>Started</th><th>Duration</th><th>Error</th></tr></thead>
				<tbody>%s</tbody>
			</table>
		</div>
	`, led, html.EscapeString(h.Hostname), stateClass, h.State, h.MAC, h.ServerType, ip, html.EscapeString(h.Notes), actions.String(), opsHTML.String()))
}

func imagesPage(images []model.Image) string {
	var rows strings.Builder
	for _, img := range images {
		def := ""
		if img.IsDefault {
			def = `<span class="badge state-green">default</span>`
		} else {
			def = fmt.Sprintf(`<form method="POST" action="/images/%d/default" class="inline"><button class="btn" style="font-size:0.7rem;padding:0.25rem 0.5rem">Set Default</button></form>`, img.ID)
		}
		deleteBtn := fmt.Sprintf(`<form method="POST" action="/images/%d/delete" class="inline" onsubmit="return confirm('Delete image %s?')"><button class="btn btn-danger" style="font-size:0.7rem;padding:0.25rem 0.5rem">Delete</button></form>`, img.ID, html.EscapeString(img.Name))
		rows.WriteString(fmt.Sprintf(`<tr><td>%s</td><td>%s</td><td>%s</td><td>%s</td><td>%s</td><td>%s</td></tr>`,
			html.EscapeString(img.Name), img.Kind, img.Version, def, img.CreatedAt.Format("2006-01-02"), deleteBtn))
	}
	if len(images) == 0 {
		rows.WriteString(`<tr><td colspan="6" class="empty">No images uploaded yet.</td></tr>`)
	}
	return layout("Images", fmt.Sprintf(`
		<div class="actions">
			<a href="/images/new" class="btn">Upload Image</a>
			<span class="count">%d images</span>
		</div>
		<div class="panel">
			<table class="ops-table">
				<thead><tr><th>Name</th><th>Kind</th><th>Version</th><th>Default</th><th>Added</th><th></th></tr></thead>
				<tbody>%s</tbody>
			</table>
		</div>
	`, len(images), rows.String()))
}

func imageUploadForm(errMsg string) string {
	errHTML := ""
	if errMsg != "" {
		errHTML = fmt.Sprintf(`<div class="error">%s</div>`, html.EscapeString(errMsg))
	}
	return layout("Upload Image", fmt.Sprintf(`
		<h2>Upload Boot Image</h2>
		%s
		<form id="upload-form" method="POST" action="/images/upload" enctype="multipart/form-data" class="form">
			<input type="hidden" name="upload_id" id="upload-id" value="">
			<label>Name<input type="text" name="name" placeholder="proxmox-8.2" required pattern="[a-z0-9][a-z0-9.\-]*"></label>
			<label>Version<input type="text" name="version" placeholder="8.2-1" required></label>
			<label>Kind
				<select name="kind">
					<option value="proxmox" selected>Proxmox VE</option>
				</select>
			</label>
			<label>ISO File<input type="file" name="iso" accept=".iso" required></label>
			<button type="submit" class="btn">Upload &amp; Extract</button>
		</form>
		<div id="upload-progress" style="display:none" class="upload-progress">
			<h3 id="progress-title">Uploading ISO...</h3>
			<div class="progress-bar-track">
				<div class="progress-bar-fill" id="progress-fill"></div>
			</div>
			<div class="progress-text" id="progress-text">Preparing upload...</div>
			<div class="progress-detail" id="progress-detail"></div>
		</div>
	`, errHTML))
}

func stateColor(s model.HostState) string {
	switch s {
	case model.StateRegistered:
		return "state-grey"
	case model.StatePXEReady, model.StatePXEBooted, model.StateInstalling:
		return "state-blue"
	case model.StateInstalled, model.StateFirstBoot, model.StateJoining:
		return "state-amber"
	case model.StateReady:
		return "state-green"
	case model.StateFailed:
		return "state-red"
	default:
		return "state-grey"
	}
}

func ledClass(s model.HostState) string {
	switch s {
	case model.StateRegistered:
		return "led-grey"
	case model.StatePXEReady, model.StatePXEBooted, model.StateInstalling:
		return "led-blue"
	case model.StateInstalled, model.StateFirstBoot, model.StateJoining:
		return "led-amber"
	case model.StateReady:
		return "led-green"
	case model.StateFailed:
		return "led-red"
	default:
		return "led-grey"
	}
}

func layout(title, body string) string {
	return fmt.Sprintf(`<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="utf-8">
	<meta name="viewport" content="width=device-width, initial-scale=1">
	<title>%s — Provisioning</title>
	<link rel="preconnect" href="https://fonts.googleapis.com">
	<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
	<link href="https://fonts.googleapis.com/css2?family=IBM+Plex+Mono:wght@400;500;600&family=Outfit:wght@400;500;600;700&display=swap" rel="stylesheet">
	<link rel="stylesheet" href="/static/app.css">
</head>
<body>
	<nav class="topbar">
		<a href="/" class="brand">Provisioning</a>
		<div class="nav-links">
			<a href="/">Dashboard</a>
			<a href="/images">Images</a>
		</div>
		<div class="sse-status">
			<span class="sse-label">Link</span>
			<span class="led led-grey" id="sse-dot"></span>
		</div>
	</nav>
	<main>%s</main>
	<script src="/static/app.js"></script>
</body>
</html>`, html.EscapeString(title), body)
}