import { type NextRequest, NextResponse } from "next/server"

const FIXED_DIMENSIONS = { width: 864, height: 1184 }

const STYLE_DESCRIPTIONS: Record<string, string> = {
  noir: "film noir style, high contrast black and white, deep dramatic shadows, 1940s detective aesthetic, heavy bold inking, moody atmospheric lighting",
  manga:
    "Japanese manga style, clean precise black linework, screen tone shading, expressive eyes, dynamic speed lines, black and white with impact effects",
  superhero:
    "classic American superhero comic style, bold vibrant colors, dynamic heroic poses, detailed muscular anatomy, Jim Lee and Jack Kirby inspired",
  vintage:
    "Golden Age 1950s comic style, visible halftone Ben-Day dots, limited retro color palette, nostalgic warm tones, classic adventure comics",
  modern:
    "contemporary digital comic art, smooth gradient coloring, detailed realistic backgrounds, cinematic widescreen composition, graphic novel quality",
  watercolor:
    "painted watercolor comic style, soft blended edges, flowing artistic colors, delicate linework with painted fills, ethereal atmosphere",
}

async function analyzeCharacterImage(imageBase64: string, apiKey: string, characterNumber: number): Promise<string> {
  try {
    // Clean base64 string
    const base64Data = imageBase64.replace(/^data:image\/[^;]+;base64,/, "")

    const response = await fetch("https://api.together.xyz/v1/chat/completions", {
      method: "POST",
      headers: {
        Authorization: `Bearer ${apiKey}`,
        "Content-Type": "application/json",
      },
      body: JSON.stringify({
        model: "meta-llama/Llama-3.2-11B-Vision-Instruct-Turbo",
        messages: [
          {
            role: "user",
            content: [
              {
                type: "text",
                text: `Analyze this person for a comic book character reference. Provide a detailed physical description in one paragraph. Include:
- Gender and approximate age
- Face shape (round, oval, square, etc.)
- Hair: color, length, style, texture
- Eye color and shape
- Skin tone
- Body type/build
- Any distinctive features (glasses, facial hair, freckles, etc.)
- Current outfit/clothing style and colors

Be VERY specific and detailed. This description will be used to draw this exact person as a comic character. Respond ONLY with the physical description, no other text.`,
              },
              {
                type: "image_url",
                image_url: {
                  url: `data:image/jpeg;base64,${base64Data}`,
                },
              },
            ],
          },
        ],
        max_tokens: 500,
        temperature: 0.3,
      }),
    })

    if (!response.ok) {
      console.error(`[v0] Vision API error for character ${characterNumber}:`, await response.text())
      return `Character ${characterNumber}`
    }

    const data = await response.json()
    const description = data.choices?.[0]?.message?.content || `Character ${characterNumber}`
    console.log(`[v0] Character ${characterNumber} description:`, description)
    return description
  } catch (error) {
    console.error(`[v0] Error analyzing character ${characterNumber}:`, error)
    return `Character ${characterNumber}`
  }
}

export async function POST(request: NextRequest) {
  try {
    const {
      prompt,
      apiKey,
      style = "noir",
      characterImages = [],
      isContinuation = false,
      previousContext = "",
    } = await request.json()

    if (!prompt || !apiKey) {
      return NextResponse.json({ error: "Missing required fields" }, { status: 400 })
    }

    const dimensions = FIXED_DIMENSIONS
    const styleDesc = STYLE_DESCRIPTIONS[style] || STYLE_DESCRIPTIONS.noir

    const continuationContext =
      isContinuation && previousContext
        ? `\nCONTINUATION CONTEXT:\nThis is a continuation of an existing story. The previous page showed: ${previousContext}\nMaintain visual consistency with the previous panels. Continue the narrative naturally.\n`
        : ""

    let characterSection = ""
    if (characterImages.length > 0) {
      console.log(`[v0] Analyzing ${characterImages.length} character image(s)...`)

      const characterDescriptions = await Promise.all(
        characterImages.map((img: string, index: number) => analyzeCharacterImage(img, apiKey, index + 1)),
      )

      if (characterImages.length === 1) {
        characterSection = `
MAIN CHARACTER (MUST APPEAR IN EVERY PANEL):
${characterDescriptions[0]}

CRITICAL INSTRUCTIONS:
- This EXACT character must appear in ALL 5 panels
- Draw them in ${style} comic art style but keep their EXACT appearance
- Same face, same hair, same outfit, same features in every panel
- They are the PROTAGONIST - center of every scene`
      } else if (characterImages.length === 2) {
        characterSection = `
TWO MAIN CHARACTERS (BOTH MUST APPEAR TOGETHER IN MOST PANELS):

CHARACTER 1 - "FIRST PERSON":
${characterDescriptions[0]}

CHARACTER 2 - "SECOND PERSON":
${characterDescriptions[1]}

CRITICAL INSTRUCTIONS:
- BOTH characters must appear together in at least 4 of the 5 panels
- Keep them VISUALLY DISTINCT - do not mix up their features
- CHARACTER 1 and CHARACTER 2 are DIFFERENT PEOPLE with different appearances
- If one is female and one is male, keep their genders correct
- Draw both in ${style} comic art style but preserve their EXACT individual appearances
- Each character must be immediately recognizable in every panel they appear
- They are the two protagonists interacting with each other throughout the story`
      }
    }

    const systemPrompt = `Professional comic book page illustration.
${continuationContext}
TEXT AND LETTERING (CRITICAL):
- All text in speech bubbles must be PERFECTLY CLEAR, LEGIBLE, and correctly spelled
- Use bold clean comic book lettering, large and easy to read
- Speech bubbles: crisp white fill, solid black outline, pointed tail toward speaker
- Keep dialogue SHORT: maximum 1-2 sentences per bubble
- NO blurry, warped, or unreadable text

PAGE LAYOUT:
5-panel comic page arranged as:
[Panel 1] [Panel 2] — top row, 2 equal panels
[    Panel 3      ] — middle row, 1 large cinematic hero panel
[Panel 4] [Panel 5] — bottom row, 2 equal panels
- Solid black panel borders with clean white gutters between panels
- Each panel clearly separated and distinct

ART STYLE:
${styleDesc}
${characterSection}

COMPOSITION:
- Vary camera angles across panels: close-up, medium shot, wide establishing shot
- Natural visual flow: left-to-right, top-to-bottom reading order
- Dynamic character poses with clear expressive acting
- Detailed backgrounds matching the scene and mood`

    const fullPrompt = `${systemPrompt}\n\nSTORY:\n${prompt}`

    const requestBody = {
      model: "google/flash-image-2.5",
      prompt: fullPrompt,
      width: dimensions.width,
      height: dimensions.height,
      n: 1,
    }

    console.log("[v0] Generating comic with prompt length:", fullPrompt.length)

    const response = await fetch("https://api.together.xyz/v1/images/generations", {
      method: "POST",
      headers: {
        Authorization: `Bearer ${apiKey}`,
        "Content-Type": "application/json",
      },
      body: JSON.stringify(requestBody),
    })

    if (!response.ok) {
      const errorData = await response.json()
      console.error("[v0] Together AI API error:", errorData)

      if (response.status === 402) {
        return NextResponse.json(
          {
            error:
              "Insufficient API credits. Please add credits to your Together.ai account at https://api.together.ai/settings/billing or update your API key.",
            errorType: "credit_limit",
          },
          { status: 402 },
        )
      }

      return NextResponse.json(
        {
          error: errorData.error?.message || `Failed to generate image: ${response.statusText}`,
          errorType: errorData.error?.type || "api_error",
        },
        { status: response.status },
      )
    }

    const data = await response.json()

    if (!data.data || !data.data[0] || !data.data[0].url) {
      return NextResponse.json({ error: "No image URL in response" }, { status: 500 })
    }

    return NextResponse.json({ imageUrl: data.data[0].url })
  } catch (error) {
    console.error("[v0] Error in generate-comic API:", error)
    return NextResponse.json(
      { error: `Internal server error: ${error instanceof Error ? error.message : "Unknown error"}` },
      { status: 500 },
    )
  }
}